DICOM Standard Browser

by Innolitics

CR ImageCIOD
CT ImageCIOD
MR ImageCIOD
NM ImageCIOD
US ImageCIOD
US Multi-frame ImageCIOD
SC ImageCIOD
Multi-frame Single Bit SC ImageCIOD
Multi-frame Grayscale Byte SC ImageCIOD
Multi-frame Grayscale Word SC ImageCIOD
Multi-frame True Color SC ImageCIOD
X-Ray Angiographic ImageCIOD
XRF ImageCIOD
RT ImageCIOD
PatientMModule - Patient
Clinical Trial SubjectUModule - Patient
General StudyMModule - Study
Patient StudyUModule - Study
Clinical Trial StudyUModule - Study
RT SeriesMModule - Series
Clinical Trial SeriesUModule - Series
Frame of ReferenceUModule - Frame of Reference
General EquipmentMModule - Equipment
General ImageMModule - Image
General ReferenceUModule - Image
Image PixelMModule - Image
Contrast/BolusCModule - Image
CineCModule - Image
Multi-frameCModule - Image
DeviceUModule - Image
RT ImageMModule - Image
(0028,0002) Samples per Pixel1Unsigned Short
(0028,0004) Photometric Interpretation1Code String
(0028,0100) Bits Allocated1Unsigned Short
(0028,0101) Bits Stored1Unsigned Short
(0028,0102) High Bit1Unsigned Short
(0028,0103) Pixel Representation1Unsigned Short
(0028,1040) Pixel Intensity Relationship3Code String
(0028,1041) Pixel Intensity Relationship Sign1CSigned Short
(3002,0002) RT Image Label1Short String
(3002,0003) RT Image Name3Long String
(3002,0004) RT Image Description3Short Text
(0008,0008) Image Type1Code String
(0008,0064) Conversion Type2Code String
(3002,000A) Reported Values Origin2CCode String
(3002,000C) RT Image Plane1Code String
(3002,000D) X-Ray Image Receptor Translation3Decimal String
(3002,000E) X-Ray Image Receptor Angle2Decimal String
(3002,0010) RT Image Orientation2CDecimal String
(3002,0011) Image Plane Pixel Spacing2Decimal String
(3002,0012) RT Image Position2Decimal String
(3002,0020) Radiation Machine Name2Short String
(300A,00B3) Primary Dosimeter Unit2Code String
(3002,0022) Radiation Machine SAD2Decimal String
(3002,0024) Radiation Machine SSD3Decimal String
(3002,0026) RT Image SID2Decimal String
(3002,0028) Source to Reference Object Distance3Decimal String
(300C,0002) Referenced RT Plan Sequence3Sequence
(300C,0006) Referenced Beam Number3Integer String
(300C,0022) Referenced Fraction Group Number3Integer String
(3002,0029) Fraction Number3Integer String
(300C,0008) Start Cumulative Meterset Weight3Decimal String
(300C,0009) End Cumulative Meterset Weight3Decimal String
(3002,0030) Exposure Sequence3Sequence
(3002,0040) Fluence Map Sequence1CSequence
(300A,011E) Gantry Angle3Decimal String
(300A,014A) Gantry Pitch Angle3Single
(300A,0120) Beam Limiting Device Angle3Decimal String
(300A,0122) Patient Support Angle3Decimal String
(300A,0124) Table Top Eccentric Axis Distance3Decimal String
(300A,0125) Table Top Eccentric Angle3Decimal String
(300A,0140) Table Top Pitch Angle3Single
(300A,0144) Table Top Roll Angle3Single
(300A,0128) Table Top Vertical Position3Decimal String
(300A,0129) Table Top Longitudinal Position3Decimal String
(300A,012A) Table Top Lateral Position3Decimal String
(300A,012C) Isocenter Position3Decimal String
(0018,5100) Patient Position1CCode String
(0018,1150) Exposure Time3Integer String
(0018,9328) Exposure Time in ms3Double
(3002,0032) Meterset Exposure3Decimal String
Modality LUTUModule - Image
VOI LUTUModule - Image
ApprovalUModule - Image
SOP CommonMModule - Image
Common Instance ReferenceUModule - Image
Frame ExtractionCModule - Image
RT DoseCIOD
RT Structure SetCIOD
RT PlanCIOD
PET ImageCIOD
Digital X-Ray ImageCIOD
Digital Mammography X-Ray ImageCIOD
Digital Intra-Oral X-Ray ImageCIOD
RT Beams Treatment RecordCIOD
RT Brachy Treatment RecordCIOD
RT Treatment Summary RecordCIOD
VL Endoscopic ImageCIOD
VL Microscopic ImageCIOD
VL Slide-Coordinates Microscopic ImageCIOD
VL Photographic ImageCIOD
Video Endoscopic ImageCIOD
Video Microscopic ImageCIOD
Video Photographic ImageCIOD
VL Whole Slide Microscopy ImageCIOD
Grayscale Softcopy Presentation StateCIOD
Color Softcopy Presentation StateCIOD
Pseudo-Color Softcopy Presentation StateCIOD
Blending Softcopy Presentation StateCIOD
Basic Structured DisplayCIOD
XA/XRF Grayscale Softcopy Presentation StateCIOD
Advanced Blending Presentation StateCIOD
Basic Voice AudioCIOD
12-Lead ECGCIOD
General ECGCIOD
Ambulatory ECGCIOD
HemodynamicCIOD
Basic Cardiac EPCIOD
Arterial Pulse WaveformCIOD
Respiratory WaveformCIOD
General Audio WaveformCIOD
Basic Text SRCIOD
Enhanced SRCIOD
Comprehensive SRCIOD
Key Object Selection DocumentCIOD
Mammography CAD SRCIOD
Chest CAD SRCIOD
Procedure LogCIOD
X-Ray Radiation Dose SRCIOD
Spectacle Prescription ReportCIOD
Colon CAD SRCIOD
Macular Grid Thickness and Volume ReportCIOD
Implantation Plan SR DocumentCIOD
Comprehensive 3D SRCIOD
Radiopharmaceutical Radiation Dose SRCIOD
Extensible SRCIOD
Acquisition Context SRCIOD
Simplified Adult Echo SRCIOD
Patient Radiation Dose Structured ReportCIOD
Enhanced MR ImageCIOD
MR SpectroscopyCIOD
Enhanced MR Color ImageCIOD
Raw DataCIOD
Enhanced CT ImageCIOD
Spatial RegistrationCIOD
Deformable Spatial RegistrationCIOD
Spatial FiducialsCIOD
Ophthalmic Photography 8 Bit ImageCIOD
Ophthalmic Photography 16 Bit ImageCIOD
Stereometric RelationshipCIOD
Hanging ProtocolCIOD
Encapsulated PDFCIOD
Encapsulated CDACIOD
Real World Value MappingCIOD
Enhanced X-Ray Angiographic ImageCIOD
Enhanced X-Ray RF ImageCIOD
RT Ion PlanCIOD
RT Ion Beams Treatment RecordCIOD
SegmentationCIOD
Ophthalmic Tomography ImageCIOD
X-Ray 3D Angiographic ImageCIOD
X-Ray 3D Craniofacial ImageCIOD
Breast Tomosynthesis ImageCIOD
Enhanced PET ImageCIOD
Surface SegmentationCIOD
Color PaletteCIOD
Enhanced US VolumeCIOD
Lensometry MeasurementsCIOD
Autorefraction MeasurementsCIOD
Keratometry MeasurementsCIOD
Subjective Refraction MeasurementsCIOD
Visual Acuity MeasurementsCIOD
Ophthalmic Axial MeasurementsCIOD
Intraocular Lens CalculationsCIOD
Generic Implant TemplateCIOD
Implant Assembly TemplateCIOD
Implant Template GroupCIOD
RT Beams Delivery InstructionCIOD
Ophthalmic Visual Field Static Perimetry MeasurementsCIOD
Intravascular OCT ImageCIOD
Ophthalmic Thickness MapCIOD
Surface Scan MeshCIOD
Surface Scan Point CloudCIOD
Legacy Converted Enhanced CT ImageCIOD
Legacy Converted Enhanced MR ImageCIOD
Legacy Converted Enhanced PET ImageCIOD
Corneal Topography MapCIOD
Breast Projection X-Ray ImageCIOD
Parametric MapCIOD
Wide Field Ophthalmic Photography Stereographic Projection ImageCIOD
Wide Field Ophthalmic Photography 3D Coordinates ImageCIOD
Tractography ResultsCIOD
RT Brachy Application Setup Delivery InstructionCIOD
Planar MPR Volumetric Presentation StateCIOD
Volume Rendering Volumetric Presentation StateCIOD
Content Assessment ResultsCIOD
Table CT Performed Procedure ProtocolCIOD
CT Defined Procedure ProtocolCIOD
Protocol ApprovalCIOD
Ophthalmic Optical Coherence Tomography En Face ImageCIOD
Ophthalmic Optical Coherence Tomography B-scan Volume AnalysisCIOD

Built with by Innolitics, a team of medical imaging software developers.

Data synced with official DICOM standard on 25 September 2017. The DICOM Standard is under continuous maintenance, and the current official version is available at http://dicom.nema.org/. DICOM Parts 3 and 6, © NEMA. Please note that the most recent PDF version of the standard is the official reference, and should checked when making technical decisions.

Referenced Beam Number Attribute

Tag(300C,0006)
TypeOptional (3)
KeywordReferencedBeamNumber
Value Multiplicity1
Value RepresentationInteger String (IS)

Uniquely identifies the corresponding N-segment treatment beam specified by Beam Number (300A,00C0) within Beam Sequence (300A,00B0) in RT Beams Module within the RT Plan referenced in Referenced RT Plan Sequence (300C,0002) or the Ion Beam Sequence (300A,03A2) in the RT Ion Beams Module within the RT Ion Plan referenced in Referenced RT Plan Sequence (300C,0002).

RT Beams Module

C.8.8.14 RT Beams Module

The RT Beams Module contains information defining equipment parameters for delivery of external radiation beams.

Table C.8-50. RT Beams Module Attributes

Attribute Name

Tag

Type

Attribute Description

Beam Sequence

(300A,00B0)

1

Sequence of treatment beams for current RT Plan.

One or more Items shall be included in this Sequence.

>Beam Number

(300A,00C0)

1

Identification number of the Beam. The value of Beam Number (300A,00C0) shall be unique within the RT Plan in which it is created. See Note 1.

>Beam Name

(300A,00C2)

3

User-defined name for Beam. See Note 1.

>Beam Description

(300A,00C3)

3

User-defined description for Beam. See Note 1.

>Beam Type

(300A,00C4)

1

Motion characteristic of Beam. See Note 5.

Enumerated Values:

STATIC

All Control Point Sequence (300A,0111) attributes remain unchanged between consecutive pairs of control points with changing Cumulative Meterset Weight (300A,0134).

DYNAMIC

One or more Control Point Sequence (300A,0111) attributes change between one or more consecutive pairs of control points with changing Cumulative Meterset Weight (300A,0134).

>Radiation Type

(300A,00C6)

2

Particle type of Beam.

Defined Terms:

PHOTON

ELECTRON

NEUTRON

PROTON

>Primary Fluence Mode Sequence

(3002,0050)

3

Sequence defining whether the primary fluence of the treatment beam uses a non-standard fluence-shaping.

Only a single item is permitted in this Sequence.

>>Fluence Mode

(3002,0051)

1

Describes whether the fluence shaping is the standard mode for the beam or an alternate.

Enumerated Values:

STANDARD

Uses standard fluence-shaping

NON_STANDARD

Uses a non-standard fluence-shaping mode

>>Fluence Mode ID

(3002,0052)

1C

Identifier for the specific fluence-shaping mode.

Required if Fluence Mode (3002,0051) has value NON_STANDARD.

>High-Dose Technique Type

(300A,00C7)

1C

Type of high-dose treatment technique.

Defined Terms:

TBI

Total Body Irradiation

HDR

High Dose Rate

Required if treatment technique requires a dose that would normally require overriding of treatment machine safety controls.

>Treatment Machine Name

(300A,00B2)

2

User-defined name identifying treatment machine to be used for beam delivery. See Note 2.

>Manufacturer

(0008,0070)

3

Manufacturer of the equipment to be used for beam delivery.

>Institution Name

(0008,0080)

3

Institution where the equipment is located that is to be used for beam delivery.

>Institution Address

(0008,0081)

3

Mailing address of the institution where the equipment is located that is to be used for beam delivery.

>Institutional Department Name

(0008,1040)

3

Department in the institution where the equipment is located that is to be used for beam delivery.

>Manufacturer's Model Name

(0008,1090)

3

Manufacturer's model name of the equipment that is to be used for beam delivery.

>Device Serial Number

(0018,1000)

3

Manufacturer's serial number of the equipment that is to be used for beam delivery.

>Primary Dosimeter Unit

(300A,00B3)

3

Measurement unit of machine dosimeter.

See Section C.8.8.14.1.

Enumerated Values:

MU

Monitor Unit

MINUTE

minute

>Referenced Tolerance Table Number

(300C,00A0)

3

Uniquely identifies Tolerance Table specified by Tolerance Table Number (300A,0042) within Tolerance Table Sequence in RT Tolerance Tables Module. These tolerances are to be used for verification of treatment machine settings.

>Source-Axis Distance

(300A,00B4)

3

Radiation source to Gantry rotation axis distance of the equipment that is to be used for beam delivery (mm).

>Beam Limiting Device Sequence

(300A,00B6)

1

Sequence of beam limiting device (collimator) jaw or leaf (element) sets.

One or more Items shall be included in this Sequence.

>>RT Beam Limiting Device Type

(300A,00B8)

1

Type of beam limiting device (collimator).

Enumerated Values:

X

symmetric jaw pair in IEC X direction

Y

symmetric jaw pair in IEC Y direction

ASYMX

asymmetric jaw pair in IEC X direction

ASYMY

asymmetric pair in IEC Y direction

MLCX

multileaf (multi-element) jaw pair in IEC X direction

MLCY

multileaf (multi-element) jaw pair in IEC Y direction

>>Source to Beam Limiting Device Distance

(300A,00BA)

3

Radiation source to beam limiting device (collimator) distance of the equipment that is to be used for beam delivery (mm).

>>Number of Leaf/Jaw Pairs

(300A,00BC)

1

Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).

>>Leaf Position Boundaries

(300A,00BE)

2C

Boundaries of beam limiting device (collimator) leaves (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), i.e., X-axis for MLCY, Y-axis for MLCX. Contains N+1 values, where N is the Number of Leaf/Jaw Pairs (300A,00BC), starting from Leaf (Element) Pair 1. Required if RT Beam Limiting Device Type (300A,00B8) is MLCX or MLCY. May be present otherwise. See Note 3.

>Referenced Patient Setup Number

(300C,006A)

3

Uniquely identifies Patient Setup to be used for current beam, specified by Patient Setup Number (300A,0182) within Patient Setup Sequence of RT Patient Setup Module.

>Referenced Reference Image Sequence

(300C,0042)

3

Reference images used for validation of current beam. One or more Items are permitted in this Sequence.

>>Include Table 10-11 “SOP Instance Reference Macro Attributes”

>>Reference Image Number

(300A,00C8)

1

Uniquely identifies Reference Image within Referenced Reference Image Sequence (300C,0042).

>>Start Cumulative Meterset Weight

(300C,0008)

3

Cumulative Meterset Weight within current Beam at which image acquisition starts.

>>End Cumulative Meterset Weight

(300C,0009)

3

Cumulative Meterset Weight within current Beam at which image acquisition ends.

>Planned Verification Image Sequence

(300A,00CA)

3

Sequence of planned verification images to be acquired during current beam.

One or more Items are permitted in this Sequence.

See Section C.8.8.14.2.

>>Start Cumulative Meterset Weight

(300C,0008)

3

Cumulative Meterset Weight within current Beam at which image acquisition will start.

>>Meterset Exposure

(3002,0032)

3

Meterset duration over which image is to be acquired, specified in Monitor units (MU) or minutes as defined by Primary Dosimeter Unit (300A,00B3).

>>End Cumulative Meterset Weight

(300C,0009)

3

Cumulative Meterset Weight within current Beam at which image acquisition will end.

>>RT Image Plane

(3002,000C)

3

Describes whether or not image plane is normal to beam axis.

Enumerated Values:

NORMAL

image plane normal to beam axis

NON_NORMAL

image plane non-normal to beam axis

>>X-Ray Image Receptor Angle

(3002,000E)

3

X-Ray Image Receptor Angle i.e., orientation of IEC X-RAY IMAGE RECEPTOR coordinate system with respect to IEC GANTRY coordinate system (degrees). See Section C.8.8.14.3.

>>RT Image Orientation

(3002,0010)

3

The direction cosines of the first row and the first column with respect to the IEC X-RAY IMAGE RECEPTOR coordinate system.

>>RT Image Position

(3002,0012)

3

The x and y coordinates (in mm) of the upper left hand corner of the image, in the IEC X-RAY IMAGE RECEPTOR coordinate system. This is the center of the first pixel transmitted.

>>RT Image SID

(3002,0026)

3

Radiation machine source to image plane distance (mm).

>>Imaging Device-Specific Acquisition Parameters

(300A,00CC)

3

User-specified device-specific parameters that describe how the imager will acquire the image.

>>Referenced Reference Image Number

(300C,0007)

3

Uniquely identifies Reference Image to which planned verification image is related, specified by Reference Image Number (300A,00C8) within Referenced Reference Image Sequence (300C,0042).

>Treatment Delivery Type

(300A,00CE)

3

Delivery Type of treatment.

Defined Terms:

TREATMENT

normal patient treatment

OPEN_PORTFILM

portal image acquisition with open field

TRMT_PORTFILM

portal image acquisition with treatment port

CONTINUATION

continuation of interrupted treatment

SETUP

no treatment beam is applied for this RT Beam. To be used for specifying the gantry, couch, and other machine positions where X-Ray set-up images or measurements are to be taken

>Referenced Dose Sequence

(300C,0080)

3

Related instances of RT Dose (for grids, isodose curves, and named/unnamed point doses).

One or more Items are permitted in this Sequence.

>>Include Table 10-11 “SOP Instance Reference Macro Attributes”

>Number of Wedges

(300A,00D0)

1

Number of wedges associated with current Beam.

>Wedge Sequence

(300A,00D1)

1C

Sequence of treatment wedges. Required if Number of Wedges (300A,00D0) is non-zero. One or more Items shall be included in this Sequence.

>>Wedge Number

(300A,00D2)

1

Identification number of the Wedge. The value of Wedge Number (300A,00D2) shall be unique within the Beam in which it is created.

>>Wedge Type

(300A,00D3)

2

Type of wedge (if any) defined for Beam.

Defined Terms:

STANDARD

standard (static) wedge

DYNAMIC

moving beam limiting device (collimator) jaw simulating wedge

MOTORIZED

single wedge that can be removed from beam remotely

>>Wedge ID

(300A,00D4)

3

User-supplied identifier for Wedge.

>>Accessory Code

(300A,00F9)

3

An identifier for the accessory intended to be read by a device such as a bar-code reader.

>>Wedge Angle

(300A,00D5)

2

Nominal wedge angle (degrees).

>>Wedge Factor

(300A,00D6)

2

Nominal wedge factor under machine calibration conditions at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111).

>>Wedge Orientation

(300A,00D8)

2

Orientation of wedge, i.e., orientation of IEC WEDGE FILTER coordinate system with respect to IEC BEAM LIMITING DEVICE coordinate system (degrees).

>>Source to Wedge Tray Distance

(300A,00DA)

3

Radiation source to wedge tray attachment edge distance (in mm) for current wedge.

>>Effective Wedge Angle

(300A,00DE)

3

Effective wedge angle (degrees). See Section C.8.8.14.14.

>Number of Compensators

(300A,00E0)

1

Number of compensators associated with current Beam.

>Total Compensator Tray Factor

(300A,00E2)

3

Compensator Tray transmission factor (between 0 and 1), at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111).

>Compensator Sequence

(300A,00E3)

1C

Sequence of treatment compensators.

One or more Items shall be included in this Sequence.

Required if Number of Compensators (300A,00E0) is non-zero.

>>Compensator Description

(300A,02EB)

3

User defined description for the compensator.

>>Compensator Number

(300A,00E4)

1C

Identification number of the Compensator. The value of Compensator Number (300A,00E4) shall be unique within the Beam in which it is created. Required if Number of Compensators (300A,00E0) is non-zero.

>>Compensator Type

(300A,00EE)

3

Type of compensator (if any).

Defined Terms:

STANDARD

physical (static) compensator

DYNAMIC

moving Beam Limiting Device (collimator) simulating physical compensator

>>Material ID

(300A,00E1)

2C

User-supplied identifier for material used to manufacture Compensator. Required if Number of Compensators (300A,00E0) is non-zero.

>>Compensator ID

(300A,00E5)

3

User-supplied identifier for compensator.

>>Accessory Code

(300A,00F9)

3

An identifier for the Compensator intended to be read by a device such as a bar-code reader.

>>Compensator Tray ID

(300A,00EF)

3

User-supplied identifier for compensator tray.

>>Tray Accessory Code

(300A,0355)

3

An identifier for the Tray intended to be read by a device such as a bar-code reader.

>>Source to Compensator Tray Distance

(300A,00E6)

2

Radiation source to compensator tray attachment edge distance (in mm) for current compensator.

>>Compensator Divergence

(300A,02E0)

3

Indicates presence or absence of geometrical divergence of the compensator.

Enumerated Values:

PRESENT

the compensator is shaped according to the beam geometrical divergence.

ABSENT

the compensator is not shaped according to the beam geometrical divergence.

>>Compensator Mounting Position

(300A,02E1)

3

Indicates on which side of the Compensator Tray the compensator is mounted.

Enumerated Values:

PATIENT_SIDE

the compensator is mounted on the side of the Compensator Tray that is towards the patient.

SOURCE_SIDE

the compensator is mounted on the side of the Compensator Tray that is towards the radiation source.

DOUBLE_SIDED

the compensator has a shaped (i.e., non-flat) surface on both sides of the Compensator Tray.

>>Compensator Rows

(300A,00E7)

1

Number of rows in the compensator. A row is defined to be in the X direction of the IEC Beam Limiting Device Coordinate system.

>>Compensator Columns

(300A,00E8)

1

Number of columns in the compensator. A column is defined to be in the Y direction of the IEC Beam Limiting Device Coordinate system.

>>Compensator Pixel Spacing

(300A,00E9)

1

Physical distance (in mm) between the center of each pixel projected onto machine isocentric plane. Specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing. See Section 10.7.1.3 for further explanation of the value order.

>>Compensator Position

(300A,00EA)

1

The x and y coordinates of the upper left hand corner (first pixel transmitted) of the compensator, projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).

>>Compensator Transmission Data

(300A,00EB)

1C

A data stream of the pixel samples that comprise the compensator, expressed as broad-beam transmission values (between 0 and 1) along a ray line passing through the pixel, at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111). The order of pixels encoded is left to right, top to bottom, i.e., the upper left pixel is encoded first followed by the remainder of the first row, followed by the first pixel of the 2nd row, then the remainder of the 2nd row and so on) when viewed from the radiation source. Required if Material ID (300A,00E1) is zero-length. May be present if Material ID (300A,00E1) is non-zero length. See Section C.8.8.14.10 and Section C.8.8.14.11.

Note

Compensator Transmission Data may not be properly encoded if Explicit VR Transfer Syntax is used and the VL of this attribute exceeds 65534 bytes.

>>Compensator Thickness Data

(300A,00EC)

1C

A data stream of the pixel samples that comprise the compensator, expressed as thicknesses (in mm). The order of pixels encoded is left to right, top to bottom, i.e., the upper left pixel is encoded first followed by the remainder of the first row, followed by the first pixel of the 2nd row, then the remainder of the 2nd row and so on) when viewed from the radiation source. Required if Material ID (300A,00E1) is non-zero length. May be present if Material ID (300A,00E1) is zero length. See Section C.8.8.14.9 and Section C.8.8.14.10 and Section C.8.8.14.11, “Block and Compensator Precedence for Dosimetric Calculations”.

Note

Compensator Thickness Data may not be properly encoded if Explicit VR Transfer Syntax is used and the VL of this attribute exceeds 65534 bytes.

>>Source to Compensator Distance

(300A,02E2)

1C

A data stream of the pixel samples that comprise the distance from the radiation source to the compensator surface closest to the radiation source (in mm). The order of pixels encoded is left to right, top to bottom (upper left pixel, followed by the remainder of row 1, followed by the remainder of the columns). Required if Material ID (300A,00E1) is non-zero length, and Compensator Mounting Position (300A,02E1) is DOUBLE_SIDED. May be present if Material ID (300A,00E1) is zero length and Compensator Mounting Position (300A,02E1) is DOUBLE_SIDED. See Section C.8.8.14.9 and Section C.8.8.14.11.

>Number of Boli

(300A,00ED)

1

Number of boli associated with current Beam.

>Referenced Bolus Sequence

(300C,00B0)

1C

Sequence of boli associated with Beam. Required if Number of Boli (300A,00ED) is non-zero.

One or more Items shall be included in this Sequence.

>>Referenced ROI Number

(3006,0084)

1

Uniquely identifies ROI representing the Bolus specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set in Referenced Structure Set Sequence (300C,0060) in RT General Plan Module.

>>Bolus ID

(300A,00DC)

3

User-supplied identifier for the Bolus.

>>Bolus Description

(300A,00DD)

3

User-defined description for the Bolus.

>>Accessory Code

(300A,00F9)

3

An identifier for the accessory intended to be read by a device such as a bar-code reader.

>Number of Blocks

(300A,00F0)

1

Number of shielding blocks associated with Beam.

>Total Block Tray Factor

(300A,00F2)

3

Total block tray transmission for all block trays (between 0 and 1) at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111).

>Block Sequence

(300A,00F4)

1C

Sequence of blocks associated with Beam.

One or more Items shall be included in this Sequence.

Required if Number of Blocks (300A,00F0) is non-zero.

>>Block Tray ID

(300A,00F5)

3

User-supplied identifier for block tray.

>>Tray Accessory Code

(300A,0355)

3

An identifier for the Tray intended to be read by a device such as a bar-code reader.

>>Accessory Code

(300A,00F9)

3

An identifier for the Block intended to be read by a device such as a bar-code reader.

>>Source to Block Tray Distance

(300A,00F6)

2

Radiation Source to attachment edge of block tray assembly (mm).

>>Block Type

(300A,00F8)

1

Type of block.

Enumerated Values:

SHIELDING

blocking material is inside contour

APERTURE

blocking material is outside contour

>>Block Divergence

(300A,00FA)

2

Indicates presence or otherwise of geometrical divergence.

Enumerated Values:

PRESENT

block edges are shaped for beam divergence

ABSENT

block edges are not shaped for beam divergence

>>Block Mounting Position

(300A,00FB)

3

Indicates on which side of the Block Tray the block is mounted.

Enumerated Values:

PATIENT_SIDE

the block is mounted on the side of the Block Tray that is towards the patient.

SOURCE_SIDE

the block is mounted on the side of the Block Tray that is towards the radiation source.

>>Block Number

(300A,00FC)

1

Identification number of the Block. The value of Block Number (300A,00FC) shall be unique within the Beam in which it is created.

>>Block Name

(300A,00FE)

3

User-defined name for block.

>>Material ID

(300A,00E1)

2

User-supplied identifier for material used to manufacture Block.

>>Block Thickness

(300A,0100)

2C

Physical thickness of block (in mm) parallel to radiation beam axis. Required if Material ID (300A,00E1) is non-zero length. May be present if Material ID (300A,00E1) is zero length. See Section C.8.8.14.4 and Section C.8.8.14.11.

>>Block Transmission

(300A,0102)

2C

Transmission through the block (between 0 and 1) at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Control Point Sequence (300A,0111). Required if Material ID (300A,00E1) is zero length. May be present if Material ID (300A,00E1) is non-zero length. See Section C.8.8.14.4 and Section C.8.8.14.11.

>>Block Number of Points

(300A,0104)

2

Number of (x,y) pairs defining the block edge.

>>Block Data

(300A,0106)

2

A data stream of (x,y) pairs that comprise the block edge. The number of pairs shall be equal to Block Number of Points (300A,0104), and the vertices shall be interpreted as a closed polygon. Coordinates are projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm). See Note 4.

>Applicator Sequence

(300A,0107)

3

Sequence of Applicators associated with Beam.

Only a single item is permitted in this Sequence.

>>Applicator ID

(300A,0108)

1

User or machine supplied identifier for Applicator.

>>Accessory Code

(300A,00F9)

3

An identifier for the accessory intended to be read by a device such as a bar-code reader.

>>Applicator Type

(300A,0109)

1

Type of Applicator.

Defined Terms:

ELECTRON_SQUARE

square electron applicator

ELECTRON_RECT

rectangular electron applicator

ELECTRON_CIRC

circular electron applicator

ELECTRON_SHORT

short electron applicator

ELECTRON_OPEN

open (dummy) electron applicator

PHOTON_SQUARE

square photon applicator

PHOTON_RECT

rectangular photon applicator

PHOTON_CIRC

circular photon applicator

INTRAOPERATIVE

intraoperative (custom) applicator

STEREOTACTIC

stereotactic applicator (deprecated)

>>Applicator Geometry Sequence

(300A,0431)

3

Describes the applicator aperture geometry.

Only a single Item is permitted in this Sequence.

>>>Applicator Aperture Shape

(300A,0432)

1

Aperture shape of the applicator.

Defined Terms:

SYM_SQUARE

A square-shaped aperture symmetrical to the central axis.

SYM_RECTANGLE

A rectangular-shaped aperture symmetrical to the central axis.

SYM_CIRCULAR

A circular-shaped aperture symmetrical to the central axis.

>>>Applicator Opening

(300A,0433)

1C

Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system. In case of square-shaped applicator contains the length of the sides of the square. In case of circular-shaped applicators, contains the diameter of the circular aperture.

Required if Applicator Aperture Shape (300A,0432) is SYM_SQUARE or SYM_CIRCULAR.

>>>Applicator Opening X

(300A,0434)

1C

Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in X-Direction.

Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.

>>>Applicator Opening Y

(300A,0435)

1C

Opening (in mm) of the applicator's aperture in IEC BEAM LIMITING DEVICE coordinate system in Y-Direction.

Required if Applicator Aperture Shape (300A,0432) is SYM_RECTANGLE.

>> Source to Applicator Mounting Position Distance

(300A,0436)

3

Radiation source to applicator mounting position distance (in mm) for current applicator.

>>Applicator Description

(300A,010A)

3

User-defined description for Applicator.

>General Accessory Sequence

(300A,0420)

3

Introduces a Sequence of General Accessories associated with this Beam.

One or more Items are permitted in this Sequence.

>>General Accessory Number

(300A,0424)

1

Identification Number of the General Accessory. The value shall be unique within the sequence.

>>General Accessory ID

(300A,0421)

1

User or machine supplied identifier for General Accessory.

>>General Accessory Description

(300A,0422)

3

User supplied description of General Accessory.

>>General Accessory Type

(300A,0423)

3

Specifies the type of accessory.

Defined Terms:

GRATICULE

Accessory tray with a radio-opaque grid

IMAGE_DETECTOR

Image acquisition device positioned in the beam line

RETICLE

Accessory tray with radio-transparent markers or grid

>>Accessory Code

(300A,00F9)

3

Machine-readable identifier for this accessory

>>Source to General Accessory Distance

(300A,0425)

3

Radiation source to general accessory distance (in mm) for current accessory.

>Referenced Dose Reference Sequence

(300C,0050)

3

A sequence of Dose References for which verification control points are defined.

One or more Items are permitted in this Sequence.

>>Referenced Dose Reference Number

(300C,0051)

1

Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module.

>>Depth Value Averaging Flag

(300A,0093)

1C

Whether or not the depth values have been averaged.

Enumerated Values:

YES

The values represent average values from the current Verification Control Point to the next

NO

The values refer to a single location

Required if the referenced beam describes an angular movement and the depth values change during movement.

>>Beam Dose Verification Control Point Sequence

(300A,008C)

1

Sequence of Items containing Beam Dose Coordinate Verification Control Points.

Two or more items Items shall be included in this Sequence.

>>>Cumulative Meterset Weight

(300A,0134)

1

The cumulative meterset weight value, at which the beam dose point geometrical parameters apply.

>>>Referenced Control Point Index

(300C,00F0)

1C

Uniquely identifies the Control Point specified by Control Point Index (300A,0112) within Beam referenced by Referenced Beam Number (300C,0006).

See Section C.8.8.14.16.

Required, if the Referenced Cumulative Meterset corresponds to a Control Point in the Control Point Sequence (300A,0111).

>>>Beam Dose Point Depth

(300A,0088)

1C

The depth (in mm) in the patient along a ray from the source to the dose point specified by the Dose Reference Point Coordinates (300A,0018) or the referenced ROI.

Required for all but the last Item in this Sequence and for the last Item if Depth Value Averaging Flag (300A,0093) has a value of NO.

See Note 6.

>>>Beam Dose Point Equivalent Depth

(300A 0089)

1C

The radiological depth in mm (water-equivalent depth, taking tissue heterogeneity into account) in the patient along a ray from the source to the dose point specified by the Dose Reference Point Coordinates (300A,0018) or the referenced ROI.

Required for all but the last Item in this Sequence and for the last Item if Depth Value Averaging Flag (300A,0093) has a value of NO.

See Note 6.

>>>Beam Dose Point SSD

(300A, 008A)

1C

Source to patient surface distance in mm along a ray from the source to the dose point specified by the Dose Reference Point Coordinates (300A,0018) or the referenced ROI.

Required for all but the last Item in this Sequence and for the last Item if Depth Value Averaging Flag (300A,0093) has a value of NO.

See Note 6.

>Final Cumulative Meterset Weight

(300A,010E)

1C

Value of Cumulative Meterset Weight (300A,0134) for final Control Point in Control Point Sequence (300A,0111). Required if Cumulative Meterset Weight is non-null in Control Points specified within Control Point Sequence (300A,0111). See Section C.8.8.14.1.

>Number of Control Points

(300A,0110)

1

Number of control points in Beam.

Value shall be greater than or equal to 2.

>Control Point Sequence

(300A,0111)

1

Sequence of machine configurations describing treatment beam.

The number of Items in this Sequence shall equal the value of Number of Control Points (300A,0110).

See Section C.8.8.14.5 and Section C.8.8.14.6.

>>Control Point Index

(300A,0112)

1

Index of current Control Point, starting at 0 for first Control Point.

>>Cumulative Meterset Weight

(300A,0134)

2

Cumulative weight to current control point. Cumulative Meterset Weight for the first item in Control Point Sequence shall always be zero. Cumulative Meterset Weight for the final item in Control Point Sequence shall always be equal to Final Cumulative Meterset Weight. See Section C.8.8.14.1.

>>Referenced Dose Reference Sequence

(300C,0050)

3

Introduces a sequence of Dose References for current Beam. One or more Items are permitted in this Sequence.

>>>Referenced Dose Reference Number

(300C,0051)

1

Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module.

>>>Cumulative Dose Reference Coefficient

(300A,010C)

2

Coefficient used to calculate cumulative dose contribution from this Beam to the referenced Dose Reference at the current Control Point. See Section C.8.8.14.7.

>>Referenced Dose Sequence

(300C,0080)

1C

Sequence describing related instances of RT Dose (for grids, isodose curves, and named/unnamed point doses).

One or more Items shall be included in this Sequence.

Required if RT Dose is being transmitted, and Dose Summation Type (3004,000A) equals CONTROL_POINT.

>>>Include Table 10-11 “SOP Instance Reference Macro Attributes”

>>Nominal Beam Energy

(300A,0114)

3

Nominal Beam Energy at control point (MV/MeV).

>>Dose Rate Set

(300A,0115)

3

Dose Rate to be set on treatment machine for segment beginning at current control point (e.g., MU/min).

>>Wedge Position Sequence

(300A,0116)

1C

A Sequence of Items describing Wedge Positions for the current control point.

Required for first item of Control Point Sequence if Number of Wedges (300A,00D0) is non-zero, and in subsequent control points if Wedge Position (300A,0118) changes during Beam. See Section C.8.8.14.5.

The number of items in this Sequence shall equal the value of Number of Wedges (300A,00D0).

>>>Referenced Wedge Number

(300C,00C0)

1

Uniquely references Wedge described by Wedge Number (300A,00D2) in Wedge Sequence (300A,00D1).

>>>Wedge Position

(300A,0118)

1

Position of Wedge at current Control Point.

Enumerated Values:

IN

OUT

>>Beam Limiting Device Position Sequence

(300A,011A)

1C

Sequence of beam limiting device (collimator) jaw or leaf (element) positions.

One or more Items shall be included in this Sequence.

Required for first item of Control Point Sequence, or if Beam Limiting Device changes during Beam.

>>>RT Beam Limiting Device Type

(300A,00B8)

1

Type of beam limiting device (collimator). The value of this attribute shall correspond to RT Beam Limiting Device Type (300A,00B8) defined in an item of Beam Limiting Device Sequence (300A,00B6).

Enumerated Values:

X

symmetric jaw pair in IEC X direction

Y

symmetric jaw pair in IEC Y direction

ASYMX

asymmetric jaw pair in IEC X direction

ASYMY

asymmetric pair in IEC Y direction

MLCX

multileaf (multi-element) jaw pair in IEC X direction

MLCY

multileaf (multi-element) jaw pair in IEC Y direction

>>>Leaf/Jaw Positions

(300A,011C)

1

Positions of beam limiting device (collimator) leaf (element) or jaw pairs (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), e.g., X-axis for MLCX, Y-axis for MLCY. Contains 2N values, where N is the Number of Leaf/Jaw Pairs (300A,00BC) in Beam Limiting Device Sequence (300A,00B6). Values shall be listed in IEC leaf (element) subscript order 101, 102, … 1N, 201, 202, … 2N. See Note 3.

>>Gantry Angle

(300A,011E)

1C

Gantry angle of radiation source, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Angle changes during Beam.

See Section C.8.8.14.13.

>>Gantry Rotation Direction

(300A,011F)

1C

Direction of Gantry Rotation when viewing gantry from isocenter, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Gantry Pitch Angle

(300A,014A)

3

Gantry Pitch Angle. i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). If used, must be present for first item of Control Point Sequence, or if used and Gantry Pitch Rotation Angle changes during Beam, must be present. See Section C.8.8.25.6.5.

See Section C.8.8.14.13.

>>Gantry Pitch Rotation Direction

(300A,014C)

3

Direction of Gantry Pitch Angle when viewing along the positive X-axis of the IEC GANTRY coordinate system, for segment following Control Point. If used, must be present for first item of Control Point Sequence, or if used and Gantry Pitch Rotation Direction changes during Beam, must be present. See Section C.8.8.14.8 and Section C.8.8.25.6.5.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Beam Limiting Device Angle

(300A,0120)

1C

Beam Limiting Device angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Beam Limiting Device Angle changes during Beam.

See Section C.8.8.14.13.

>>Beam Limiting Device Rotation Direction

(300A,0121)

1C

Direction of Beam Limiting Device Rotation when viewing beam limiting device (collimator) from radiation source, for segment following Control Point. Required for first item of Control Point Sequence, or if Beam Limiting Device Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Patient Support Angle

(300A,0122)

1C

Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT (turntable) coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Patient Support Angle changes during Beam.

See Section C.8.8.14.13.

>>Patient Support Rotation Direction

(300A,0123)

1C

Direction of Patient Support Rotation when viewing table from above, for segment following Control Point. Required for first item of Control Point Sequence, or if Patient Support Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Eccentric Axis Distance

(300A,0124)

3

Distance (positive) from the IEC PATIENT SUPPORT vertical axis to the IEC TABLE TOP ECCENTRIC vertical axis (mm).

>>Table Top Eccentric Angle

(300A,0125)

1C

Table Top (non-isocentric) angle, i.e., orientation of IEC TABLE TOP ECCENTRIC coordinate system with respect to IEC PATIENT SUPPORT coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Eccentric Angle changes during Beam.

See Section C.8.8.14.13.

>>Table Top Eccentric Rotation Direction

(300A,0126)

1C

Direction of Table Top Eccentric Rotation when viewing table from above, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Eccentric Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Pitch Angle

(300A,0140)

1C

Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Pitch Angle changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.12 and Section C.8.8.14.13.

>>Table Top Pitch Rotation Direction

(300A,0142)

1C

Direction of Table Top Pitch Rotation when viewing the table along the positive X-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Pitch Rotation Direction changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.8 and Section C.8.8.14.12.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Roll Angle

(300A,0144)

1C

Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the IEC Y-axis of the IEC TABLE TOP coordinate system (degrees). If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Roll Angle changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.12 and Section C.8.8.14.13.

>>Table Top Roll Rotation Direction

(300A,0146)

1C

Direction of Table Top Roll Rotation when viewing the table along the positive Y-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. If required by treatment delivery device, shall be present for first item of Control Point Sequence. If required by treatment delivery device and if Table Top Roll Rotation Direction changes during Beam, shall be present in all subsequent items of Control Point Sequence. See Section C.8.8.14.8 and Section C.8.8.14.12.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Vertical Position

(300A,0128)

2C

Table Top Vertical position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Vertical Position changes during Beam. See Section C.8.8.14.6.

>>Table Top Longitudinal Position

(300A,0129)

2C

Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Longitudinal Position changes during Beam. See Section C.8.8.14.6.

>>Table Top Lateral Position

(300A,012A)

2C

Table Top Lateral position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Lateral Position changes during Beam. See Section C.8.8.14.6.

>>Isocenter Position

(300A,012C)

2C

Isocenter coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). Required for first item of Segment Control Point Sequence, or if Segment Isocenter Position changes during Beam.

>>Surface Entry Point

(300A,012E)

3

Patient surface entry point coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).

>>External Contour Entry Point

(300A,0133)

3

External Contour entry point coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).

See Section C.8.8.14.15.

>>Source to Surface Distance

(300A,0130)

3

Source to Patient Surface (skin) distance (mm).

>>Source to External Contour Distance

(300A,0132)

3

Source to External Contour distance (mm) including devices associated with the patient anatomy model. For dosimetric purposes this value may differ from the Source to Surface Distance (300A,0130).

See Section C.8.8.14.15.


Note

  1. Beam Number (300A,00C0) is provided to link related information across modules, and its value should not be required to have any real-world interpretation. Beam Name (300A,00C2), a Type 3 attribute, is intended to store the primary beam identifier (often referred to as "field identifier"). Beam Description (300A,00C3), a Type 3 attribute, is intended to store additional beam identifying information (often referred to as "field name"). Equipment supporting both these attributes should state this clearly in the Conformance Statement.

  2. The DICOM standard does not support the transmission of treatment unit modeling information such as depth doses and beam profiles.

  3. Implementers should take note that Leaf Position Boundaries (300A,00BE) are the positions of the mechanical boundaries (projected to the isocentric plane) between beam limiting device (collimator) leaves, fixed for a given beam limiting device (collimator). Leaf/Jaw Positions (300A,011C) are values specific to a given beam control point, specifying the beam limiting device (collimator) leaf (element) openings.

  4. Block coordinates may not be transmitted when such data is not available from the transmitting system. However, the receiving system may not have internal mechanisms to use or store such data. For example, a plan transmitted from an treatment planning system to a Record and Verify (R&V) system will contain the block data for blocked beams. Subsequent transfer of beam data from the R&V system may omit this data since the R&V system may not have stored it.

  5. Refer to Section C.8.8.14.5 for examples of STATIC and DYNAMIC Beam Type. Note that beams having Wedge Type = DYNAMIC as the only moving parameter are not considered DYNAMIC according to the definition of Beam Type (300A,00C4).

  6. Attributes Beam Dose Point Depth (300A,0088), Beam Dose Point Equivalent Depth (300A,0089), Beam Dose Point SSD (300A,008A) were previously included in this Module on the level of Beam Sequence (300A,00B0) > Control Points Beam Sequence (300A,0111) > Referenced Dose Reference Sequence (300C,0050). These attributes have been retired at this location. See PS3.3-2011.

C.8.8.14.1 Meterset Calculations

The Meterset at a given Control Point is equal to Beam Meterset (300A,0086) specified in the Referenced Beam Sequence (300C,0004) of the RT Fraction Scheme Module, multiplied by the Cumulative Meterset Weight (300A,0134) for the Control Point, divided by the Final Cumulative Meterset Weight (300A,010E). The Meterset is specified in units defined by Primary Dosimeter Unit (300A,00B3). If the calculation for Meterset results in a Meterset value that is not an exact multiple of the primary Meterset resolution, then the result shall be rounded to the nearest allowed Meterset value (i.e., less than a half resolution unit shall be rounded down to the nearest resolution unit, and equal or greater than half a resolution unit shall be rounded up to the nearest resolution unit).

Note also that if Final Cumulative Meterset Weight (300A,010E) is equal to 100, then Cumulative Meterset Weight (300A,0134) becomes equivalent to the percentage of Beam Meterset (300A,0086) delivered at each control point. If Final Cumulative Meterset Weight (300A,010E) is equal to Beam Meterset (300A,0086), then the Cumulative Meterset Weight (300A,0134) at each control point becomes equal to the cumulative Meterset delivered at that control point.

C.8.8.14.2 Planned Verification Image Sequence

The Planned Verification Image Sequence (300A,00CA) contains attributes that describe the planned verification images to be acquired during current beam. The Start Cumulative Meterset Weight (300C,0008) specifies the Cumulative Meterset Weight at which image acquisition is to begin. If Meterset Exposure (3002,0032) is present in a sequence item and End Cumulative Meterset Weight (300C,0009) is not present then a single image shall be acquired using the Meterset duration specified in Meterset Exposure (3002,0032). If End Cumulative Meterset Weight (300C,0009) is present in a sequence item and Meterset Exposure (3002,0032) is not present then a single image shall be acquired over the beam delivery from Start Cumulative Meterset Weight (300C,0008) to End Cumulative Meterset Weight (300C,0009). If both Meterset Exposure (3002,0032) and End Cumulative Meterset Weight (300C,0009) are present in a sequence item then images shall be acquired every Meterset Exposure (3002,0032) from Start Cumulative Meterset Weight (300C,0008) to End Cumulative Meterset Weight (300C,0009). No images shall extend past End Cumulative Meterset Weight (300C,0009).

C.8.8.14.3 X-Ray Image Receptor Angle

The X-Ray Image Receptor Angle (3002,000E) specifies the rotation of the image receptor device in the IEC X-RAY IMAGE RECEPTOR PLANE. A positive angle corresponds to a counter-clockwise rotation of the X-Ray Image Receptor as viewed from the radiation source in the IEC GANTRY coordinate system. The normal (non-rotated) value for this parameter is zero degrees.

C.8.8.14.4 Multiple Aperture Blocks

All blocks with Block Type (300A,00F8) of APERTURE for a given beam shall have equal values of Block Transmission (300A,0102) and/or Block Thickness (300A,0100) if they are specified. The composite aperture shall be evaluated as the union of the individual apertures within a single Block. Shielding block transmission(s) shall be applied multiplicatively after the (composite) aperture has been evaluated.

C.8.8.14.5 Control Point Sequence

The RT Beams Module uses a single beam model to handle static, arc, and dynamic delivery of external beam radiation by a medical accelerator or gamma beam therapy equipment (cobalt unit). All applicable parameters shall be specified at Control Point 0, with the exception of couch positions (see Section C.8.8.14.6). All parameters that change at any control point of a given beam shall be specified explicitly at all control points (including those preceding the change). No assumptions are made about the behavior of machine parameters between specified control points, and communicating devices shall agree on this behavior outside the current standard.

The Cumulative Meterset Weight (300A,0134) values in a Control Point Sequence (300A,0111) shall be monotonically increasing in the order of increasing Control Point Index (300A,0112).

Gantry Rotation Direction (300A,011F), Beam Limiting Device Rotation Direction (300A,0121), Patient Support Rotation Direction (300A,0123), and Table Top Eccentric Rotation Direction (300A,0126) are defined as applying to the segment following the control point, and changes to these parameters during treatment may be specified without use of a "non-irradiation" segment. All other Control Point Sequence attributes are defined only at the control point. To unambiguously encode changes in discrete-valued attributes such as Wedge Position (300A,0118) and Nominal Beam Energy (300A,0114), a non-irradiation segment where Cumulative Meterset Weight (300A,0134) does not change, shall be used.

Some examples of beam specification using control points are as follows:

a) Static delivery:

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0

Control Point 1: Cumulative Meterset Weight = 1, no other parameters defined

b) Arc delivery:

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0, Gantry Rotation Direction = rotation direction, Gantry Angle = initial angle

Control Point 1: Cumulative Meterset Weight = 1, Gantry Rotation Direction = NONE, Gantry Angle = final angle

c) Dynamic delivery of two equally weighted segments:

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0

Control Point 1: All changing treatment parameters defined (including those which do not change at this control point), Cumulative Meterset Weight = 0.5

Control Point 2: All changing treatment parameters defined (including those which do not change at this control point), Cumulative Meterset Weight = 1

d) Dynamic Delivery of two unequally weighted segments with a step change in table angle:

Control Point 0: All applicable treatment parameters defined, Patient Support Angle = initial angle, Patient Support Rotation Direction = NONE, Cumulative Meterset Weight = 0

Control Point 1: All changing parameters defined (including those that do not change at this control point), Cumulative Meterset Weight = 0.3, Patient Support Angle = initial angle, Patient Support Rotation Direction = rotation direction

Control Point 2: All changing parameters defined (although none should change at this control point), Cumulative Meterset Weight = 0.3, Patient Support Angle = new angle, Patient Support Rotation Direction = NONE

Control Point 3: All changing parameters defined (including those that do not change at this control point), Cumulative Meterset Weight = 1, Patient Support Angle = new angle, Patient Support Rotation Direction = NONE

C.8.8.14.6 Absolute and Relative Machine Coordinates

All treatment machine parameters except couch translations are specified in absolute machine coordinates as defined by IEC 61217. For the Table Top Vertical Position (300A,0128), Table Top Longitudinal Position (300A,0129), and Table Top Lateral Position (300A,012A), if the first Control Point contains a value of non-zero length, all subsequent Control Point position values are absolute values in their respective coordinate system. If the first Control Point contains a zero-length value, all subsequent Control Point position values are specified relative to the (unknown) initial value.

C.8.8.14.7 Cumulative Dose Reference Coefficient

The Cumulative Dose Reference Coefficient (300A,010C) is the value by which Beam Dose (300A,0084) is multiplied to obtain the dose to the referenced dose reference site at the current control point (and after previous control points have been successfully administered). The Cumulative Dose Reference Coefficient (300A,010C) is by definition zero for the initial control point. The Cumulative Dose Reference Coefficient (300A,010C) of the final control point multiplied by Beam Dose (300A,0084) results in the final dose to the referenced dose reference site for the current beam. Dose calculation for dose reference sites other than points is not well defined.

C.8.8.14.8 Machine Rotations

For the machine rotation angles Gantry Angle (300A,011E), Beam Limiting Device Angle (300A,0120), Patient Support Angle (300A,0122), and Table Top Eccentric Angle (300A,0125), rotation direction is specified as clockwise (CW), counter-clockwise (CC), or NONE. The maximum permitted rotation between two Control Points is 360 degrees. Examples:

  1. Gantry Angle moves from 5 degrees to 5 degrees, Gantry Rotation Direction = NONE:

    No movement.

  2. Gantry Angle moves from 5 degrees to 5 degrees, Gantry Rotation Direction = CW:

    Full clockwise rotation (360 degrees).

  3. Table Angle moves from 170 degrees to 160 degrees, Table Rotation Direction = CC:

    Counter-clockwise rotation by 350 degrees (note direction of increasing table angle as defined by IEC 61217).

C.8.8.14.9 Compensator Thickness Data and Source to Compensator Distance

The values stored in Compensator Thickness Data (300A,00EC) and Source to Compensator Distance (300A,02E2) shall be parallel to the radiation beam axis if Compensator Divergence (300A,02E0) equals ABSENT, or divergent according to the beam geometrical divergence if Compensator Divergence (300A,02E0) equals PRESENT. If Compensator Divergence (300A,02E0) is not present, then the parallel or divergent nature of the thicknesses is as if ABSENT was specified for Compensator Divergence (300A,02E0).

C.8.8.14.10 Compensator Transmission and Thickness Data Direction

The direction of the rows and columns in Compensator Transmission Data (300A,00EB) and Compensator Thickness Data (300A,00EC) is defined as follows: The direction of rows goes along the positive Xb direction and the direction of the columns does along the negative Yb direction of the IEC X-BEAM LIMITING DEVICE coordinate system. Other interpretations shall be documented in an implementation's conformance statement.

C.8.8.14.11 Block and Compensator Precedence for Dosimetric Calculations

If Block Thickness (300A,0100) and Block Transmission (300A,0102) are present, Block Transmission shall have precedence for dosimetric calculations. If Compensator Transmission Data (300A,00EB) and Compensator Thickness Data (300A,00EC) are present, Compensator Transmission Data shall have precedence for dosimetric calculations.

C.8.8.14.12 Table Top Pitch and Table Top Roll

Pitch and Roll Coordinate Systems of the Table Top are defined in IEC 61217 Edition 1.2 2008-04. These angles are defined as rotations of the IEC Table Top System as indicated below.

The Table Top Pitch Angle is defined as the rotation of the coordinate axes Yt, Zt about axis Xt by an angle ψt; See Figure C.8.8.14-1. An increase in the value of angle ψt corresponds to the clockwise rotation of the Table Top as viewed from the Table Top coordinate system origin along the positive Xt axis.

The Table Top Roll Angle is defined as the rotation of the coordinate axes Xt, Zt about axis Yt by an angle ψt; See Figure C.8.8.14-2. An increase in the value of angle ψt corresponds to the clockwise rotation of the Table Top as viewed from the Table Top coordinate system origin along the positive Yt axis.

It is important to observe that the point of rotation is the origin of the table top system after the rotation of the PATIENT SUPPORT(s) system about Zs by θs after the rotation of the Table top eccentric rotation (e) system about Ze by θe and after the translation of Table top (t) system along Xe Ye Ze. This means that the rotation point of the Pitch and Roll angles is typically not the isocenter. The translational values Xt Yt Zt may need to be adjusted to preserve the patient position at the isocenter. e.g., a rotation of the Pitch angle by a positive angle at a position originally at Xt=0, Yt=100 and Zt=0 will lead to a negative Zt value and a slightly lower Yt if the patient position at isocenter is to be maintained.

Figure C.8.8.14-1. Table Top Pitch Angle


Figure C.8.8.14-2. Table Top Roll Angle


C.8.8.14.13 Angular Values in RT Beams Module

The Attributes that define angles refer to coordinate systems defined by IEC 61217. Where indicated in the DICOM Attribute definition, the angle uses the coordinate system (orientation of the rotation axis and the origin of the rotating coordinate system) defined in IEC 61217, however DICOM makes no restrictions on the range of values stored. IEC 61217 defines restrictions that only apply to user interface presentation.

C.8.8.14.14 Effective Wedge Angle

The Effective Wedge Angle (300A,00DE) describes the dosimetric angle of a motorized wedge accounting for the partial presence of the wedge in the beam. The presence of the wedge in the beam is specified by the Wedge Position (300A,0118) in the Wedge Position Sequence (300A,0116) included in the Control Point Sequence (300A,0111) of the current beam. When the wedge is in the beam throughout all control points, the Effective Wedge Angle will have the same value as the Wedge Angle (300A,00D5). Otherwise the Effective Wedge Angle will have a lower value than the Wedge Angle.

C.8.8.14.15 Source to External Contour Distance and External Contour Entry Point

The Source to External Contour Distance (300A,0132) (and the Average Beam Dose Point Source to External Contour Distance (300A,0131) in the RT Fraction Scheme Module) is the distance to the beam entry point (External Contour Entry Point), which may include Bolus, Patient Positioning Devices, Patient Immobilization Devices or other devices. This value is useful for including the attenuation effects of external devices on the dose calculation and for patient setup.

C.8.8.14.16 Referenced Control Point

The number of items in the Beam Dose Verification Control Point Sequence (300A,008C) is not required to be the same as in the Control Point Sequence (300A,0111). A different sampling can be chosen for the Beam Dose Verification Control Point Sequence, but where the Cumulative Meterset Weight of a Control Point Sequence Item is the same it shall be referenced by the Referenced Control Point Index (300C,00F0).

RT Ion Beams Module

C.8.8.25 RT Ion Beams Module

The RT Ion Beams Module contains information defining equipment parameters for delivery of external Ion radiation beams.

Table C.8.8.25-1. RT Ion Beams Module Attributes

Attribute Name

Tag

Type

Description

Ion Beam Sequence

(300A,03A2)

1

Sequence of setup and/or treatment beams for current RT Ion Plan.

One or more Items shall be included in this Sequence.

>Beam Number

(300A,00C0)

1

Identification number of the Beam. The value of Beam Number (300A,00C0) shall be unique within the RT Ion Plan in which it is created. See Section C.8.8.25.1.

>Beam Name

(300A,00C2)

1

User-defined name for Beam. See Section C.8.8.25.1.

>Beam Description

(300A,00C3)

3

User-defined description for Beam. See Section C.8.8.25.1.

>Beam Type

(300A,00C4)

1

Motion characteristic of Beam.

Enumerated Values:

STATIC

all beam parameters remain unchanged during delivery

DYNAMIC

one or more beam parameters changes during delivery

>Radiation Type

(300A,00C6)

1

Particle type of Beam.

Defined Terms:

PHOTON

PROTON

ION

>Radiation Mass Number

(300A,0302)

1C

Mass number of radiation. Required if Radiation Type (300A,00C6) is ION

>Radiation Atomic Number

(300A,0304)

1C

Atomic number of radiation. Required if Radiation Type (300A,00C6) is ION

>Radiation Charge State

(300A,0306)

1C

Charge state of radiation. Required if Radiation Type (300A,00C6) is ION

>Scan Mode

(300A,0308)

1

The method of beam scanning to be used during treatment.

Defined Terms:

NONE

No beam scanning is performed.

UNIFORM

Between control points, the beam is scanned to create a uniform lateral fluence distribution across the field.

MODULATED

Between control points, the beam is scanned to create a modulated lateral fluence distribution across the field.

MODULATED_SPEC

Between control points, the beam is scanned to create a modulated lateral fluence distribution across the field. The specific scan mode is defined by Modulated Scan Mode Type (300A,0309).

>Modulated Scan Mode Type

(300A,0309)

1C

Defines the specialization of a modulated scan mode.

Defined Terms:

STATIONARY

The Meterset is delivered while the beam spot is at the specified position.

LEAPING

The delivery of the specified Meterset for the current spot position begins when the spot is at the previous spot position but the spot moves as quickly as possible to the current specified spot position where most of the Meterset is delivered.

LINEAR

The beam spot is delivered with uniform flux while traveling from one position to the next position (continuous).

MIXED

Between control points the beam may be delivered by a combination of STATIONARY, LEAPING or LINEAR modes.

Required if Scan Mode (300A,0308) is MODULATED_SPEC.

See Section C.8.8.25.8.

>Treatment Machine Name

(300A,00B2)

2

User-defined name identifying treatment machine to be used for beam delivery. See Section C.8.8.25.2.

>Manufacturer

(0008,0070)

3

Manufacturer of the equipment to be used for beam delivery.

>Institution Name

(0008,0080)

3

Institution where the equipment is located that is to be used for beam delivery.

>Institution Address

(0008,0081)

3

Mailing address of the institution where the equipment is located that is to be used for beam delivery.

>Institutional Department Name

(0008,1040)

3

Department in the institution where the equipment is located that is to be used for beam delivery.

>Manufacturer's Model Name

(0008,1090)

3

Manufacturer's model name of the equipment that is to be used for beam delivery.

>Device Serial Number

(0018,1000)

3

Manufacturer's serial number of the equipment that is to be used for beam delivery.

>Primary Dosimeter Unit

(300A,00B3)

1

Measurement unit of machine dosimeter.

Enumerated Values:

MU

Monitor Unit

NP

number of particles

>Referenced Tolerance Table Number

(300C,00A0)

3

Uniquely identifies Tolerance Table specified by Tolerance Table Number (300A,0042) within Tolerance Table Sequence in RT Ion Tolerance Tables Module. These tolerances are to be used for verification of treatment machine settings.

>Virtual Source-Axis Distances

(300A,030A)

1

Distance (in mm) from virtual source position to gantry rotation axis or nominal isocenter position (fixed beam-lines) of the equipment to be used for beam delivery. Specified by a numeric pair - the VSAD in the IEC Gantry X direction followed by the VSAD in the IEC Gantry Y direction.

The VSAD is commonly used for designing apertures in contrast to the effective source-axis-distance (ESAD) that is commonly used with the inverse square law for calculating the dose decrease with distance. See Section C.8.8.25.4.

>Depth Dose Parameters Sequence

(300A,0505)

3

Set of parameters describing the depth dose distribution.

Only a single item is permitted in this sequence.

>>Reference Dose Definition

(300A,0512)

1

Definition of the 100% reference dose level.

Defined Terms:

HIGHEST

MAXIMUM

CENTER

See Section C.8.8.25.9.

>>Distal Depth

(300A,0502)

1

Penetration depth in water (mm) of the particle excluding any user-installed range modifying devices, measured at the Distal Depth Fraction (300A,0501).

See Section C.8.8.25.9.

>>Distal Depth Fraction

(300A,0501)

1

Fraction of the value of dose relative to the 100% level defined by Reference Dose Definition (300A,0512). This determines the Distal Depth (300A,0502).

A value of 1.0 refers to 100% of the reference dose level defined by the Reference Dose Definition (300A,0512).

See Section C.8.8.25.9.

>>Nominal Range Modulated Region Depths

(300A,0504)

1C

The depths of the proximal and distal limits of the range modulated region in water.

Contains two values (in mm). The first value defines the depth of the proximal limit. The second value defines the depth of the distal limit.

Required if Reference Dose Definition (300A,0512) has the value CENTER.

See Section C.8.8.25.9.

>>Nominal Range Modulation Fractions

(300A,0503)

1C

Fractions of the Reference Dose Definition (300A,0512) defining the proximal and distal limits at which the range-modulated region is defined.

Contains two values. The first value defines the modulation fraction value at the proximal limit and the second value defines the modulation fraction value at the distal limit.

A value of 1.0 refers to the 100% reference dose level as defined in Reference Dose Definition (300A,0512).

Required if Nominal Range Modulated Region Depths (300A,0504) is present.

See Section C.8.8.25.9.

>Ion Beam Limiting Device Sequence

(300A,03A4)

3

Sequence of beam limiting device (collimator) jaw or leaf (element) sets.

One or more Items are permitted in this Sequence.

>>RT Beam Limiting Device Type

(300A,00B8)

1

Type of beam limiting device (collimator).

Enumerated Values:

X

symmetric jaw pair in IEC X direction

Y

symmetric jaw pair in IEC Y direction

ASYMX

asymmetric jaw pair in IEC X direction

ASYMY

asymmetric pair in IEC Y direction

MLCX

multileaf (multi-element) jaw pair in IEC X direction

MLCY

multileaf (multi-element) jaw pair in IEC Y direction

>>Isocenter to Beam Limiting Device Distance

(300A,00BB)

2

Isocenter to beam limiting device (collimator) distance (in mm) of the equipment that is to be used for beam delivery.

See Section C.8.8.25.4.

>>Number of Leaf/Jaw Pairs

(300A,00BC)

1

Number of leaf (element) or jaw pairs (equal to 1 for standard beam limiting device jaws).

>>Leaf Position Boundaries

(300A,00BE)

1C

Boundaries of beam limiting device (collimator) leaves (in mm) in IEC BEAM LIMITING DEVICE coordinate axis appropriate to RT Beam Limiting Device Type (300A,00B8), i.e., X-axis for MLCY, Y-axis for MLCX.

Contains N+1 values, where N is the Number of Leaf/Jaw Pairs (300A,00BC), starting from Leaf (Element) Pair 1. Required if RT Beam Limiting Device Type (300A,00B8) is MLCX or MLCY. May be present otherwise. See Section C.8.8.25.3.

>Referenced Patient Setup Number

(300C,006A)

3

Uniquely identifies Patient Setup to be used for current beam, specified by Patient Setup Number (300A,0182) within Patient Setup Sequence of RT Patient Setup Module.

>Referenced Reference Image Sequence

(300C,0042)

3

Reference images used for validation of current beam.

One or more Items are permitted in this Sequence.

>>Include Table 10-11 “SOP Instance Reference Macro Attributes”

>>Reference Image Number

(300A,00C8)

1

Uniquely identifies Reference Image within Referenced Reference Image Sequence (300C,0042).

>Treatment Delivery Type

(300A,00CE)

1

Delivery Type of treatment.

Defined Terms:

TREATMENT

Normal patient treatment

OPEN_PORTFILM

Portal image acquisition with open field (the source of radiation is specified by Radiation Type (300A,00C6))

TRMT_PORTFILM

Portal image acquisition with treatment port (the source of radiation is specified by Radiation Type (300A,00C6))

CONTINUATION

Continuation of interrupted treatment

SETUP

No treatment beam is applied for this RT Beam. To be used for specifying the gantry, couch, and other machine positions where X-Ray set-up images or measurements shall be taken.

>Referenced Dose Sequence

(300C,0080)

3

Related instances of RT Dose (for grids, isodose curves, and named/unnamed point doses).

One or more Items are permitted in this Sequence.

>>Include Table 10-11 “SOP Instance Reference Macro Attributes”

The Referenced Class SOP UID shall be that of the RT Dose SOP Class (1.2.840.10008.5.1.4.1.1.481.2.

>Number of Wedges

(300A,00D0)

1

Number of wedges associated with current beam.

>Total Wedge Tray Water-Equivalent Thickness

(300A,00D7)

3

Shift of the wedge tray induced on the range of the ion beam as measured in water (in mm).

>Ion Wedge Sequence

(300A,03AA)

1C

Sequence of treatment wedges.

Required if Number of Wedges (300A,00D0) is non-zero.

The number of items shall be identical to the value of Number of Wedges (300A,00D0).

>>Wedge Number

(300A,00D2)

1

Identification number of the Wedges. The value of Wedge Number (300A,00D2) shall be unique within the Beam in which it was created.

>>Wedge Type

(300A,00D3)

2

Type of wedge (if any) defined for Beam.

Defined Terms:

STANDARD

standard (static) wedge

MOTORIZED

single wedge that can be removed from beam remotely.

PARTIAL_STANDARD

wedge does not extend across the whole field and is operated manually.

PARTIAL_MOTORIZ

wedge does not extend across the whole field and can be removed from beam remotely.

>>Wedge ID

(300A,00D4)

3

User-supplied identifier for Wedge.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>>Wedge Angle

(300A,00D5)

2

Nominal wedge angle (degrees).

>>Wedge Orientation

(300A,00D8)

2

Orientation of wedge, i.e., orientation of IEC WEDGE FILTER coordinate system with respect to the IEC BEAM LIMITING DEVICE coordinate systems (degrees).

>>Isocenter to Wedge Tray Distance

(300A,00D9)

1

Isocenter to downstream edge of wedge tray (mm).

See Section C.8.8.25.4

>Number of Compensators

(300A,00E0)

1

Number of compensators associated with current Beam.

>Total Compensator Tray Water-Equivalent Thickness

(300A,02E3)

3

Water-Equivalent thickness of the compensator tray (in mm) parallel to radiation beam axis.

>Ion Range Compensator Sequence

(300A,02EA)

1C

Sequence of compensators.

Required if Number of Compensators (300A,00E0) is non-zero.

The number of items shall be identical to the value of Number of Compensators (300A,00E0).

>>Compensator Description

(300A,02EB)

3

User defined description for the compensator.

>>Compensator Number

(300A,00E4)

1

Identification number of the Compensator. The value of Compensator Number (300A,00E4) shall be unique within the Beam in which it is created.

>>Material ID

(300A,00E1)

2

User-supplied identifier for material used to manufacture Compensator.

>>Compensator ID

(300A,00E5)

3

User-supplied identifier for the compensator.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>>Isocenter to Compensator Tray Distance

(300A,02E4)

1C

Isocenter to compensator tray attachment edge distance (in mm) for current range compensator. Required if Compensator Mounting Position (300A,02E1) is not DOUBLE_SIDED. See Section C.8.8.25.4

>>Compensator Divergence

(300A,02E0)

1

Indicates presence or absence of geometrical divergence of the range compensator.

Enumerated Values:

PRESENT

the range compensator is shaped according to the beam geometrical divergence.

ABSENT

the range compensator is not shaped according to the beam geometrical divergence.

>>Compensator Mounting Position

(300A,02E1)

1

Indicates on which side of the Compensator Tray the compensator is mounted.

Enumerated Values:

PATIENT_SIDE

the Compensator is mounted on the side of the Compensator Tray that is towards the patient.

SOURCE_SIDE

the Compensator is mounted on the side of the Compensator Tray that is towards the radiation source.

DOUBLE_SIDED

the Compensator has a shaped (i.e., non-flat) surface on both sides of the Compensator Tray.

>>Compensator Rows

(300A,00E7)

1

Number of rows in the range compensator. A row is defined to be in the X direction of the IEC Beam Limiting Device Coordinate system.

>>Compensator Columns

(300A,00E8)

1

Number of columns in the range compensator. A column is defined to be in the Y direction of the IEC Beam Limiting Device Coordinate system.

>>Compensator Pixel Spacing

(300A,00E9)

1

Physical distance (in mm) between the center of each pixel projected onto machine isocentric plane. Specified by a numeric pair - adjacent row spacing followed by adjacent column spacing. See Section 10.7.1.3 for further explanation of the value order.

>>Compensator Position

(300A,00EA)

1

The x and y coordinates of the upper left hand corner (first pixel transmitted) of the range compensator, projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).

>>Compensator Column Offset

(300A,02E5)

1C

The offset distance (in mm) applied to the x coordinate of Compensator Position (300A,00EA) for even numbered rows. Required if the compensator pattern is hexagonal.

>>Compensator Thickness Data

(300A,00EC)

1

A data stream of the pixel samples that comprise the range compensator, expressed as physical thickness (in mm), either parallel to radiation beam axis if Compensator Divergence (300A,02E0) equals ABSENT, or divergent according to the beam geometrical divergence if Compensator Divergence (300A,02E0) equals PRESENT. The order of pixels encoded is left to right, top to bottom (upper left pixel, followed by the remainder of row 1, followed by the remainder of the rows).

>>Isocenter to Compensator Distances

(300A,02E6)

1C

A data stream of the pixel samples that comprise the distance from the isocenter to the compensator surface closest to the radiation source (in mm). The order of pixels encoded is left to right, top to bottom (upper left pixel, followed by the remainder of row 1, followed by the remainder of the rows). Required if Material ID (300A,00E1) is non-zero length, and Compensator Mounting Position (300A,02E1) is DOUBLE_SIDED. See Section C.8.8.14.9 and Section C.8.8.25.4.

>>Compensator Relative Stopping Power Ratio

(300A,02E7)

3

Compensator Linear Stopping Power Ratio, relative to water, at the beam energy specified by the Nominal Beam Energy (300A,0114) of the first Control Point of the Ion Control Point Sequence (300A,03A8).

>>Compensator Milling Tool Diameter

(300A,02E8)

3

The diameter (in mm) of the milling tool to be used to create the compensator. The diameter is expressed as the actual physical size and not a projected size at isocenter.

>Number of Boli

(300A,00ED)

1

Number of boli associated with current Beam.

>Referenced Bolus Sequence

(300C,00B0)

1C

Sequence of boli associated with Beam.

Required if Number of Boli (300A,00ED) is non-zero.

The number of items shall be identical to the value of Number of Boli (300A,00ED).

>>Referenced ROI Number

(3006,0084)

1

Uniquely identifies ROI representing the Bolus specified by ROI Number (3006,0022) in Structure Set ROI Sequence (3006,0020) in Structure Set Module within RT Structure Set in Referenced Structure Set Sequence (300C,0060) in RT General Plan Module.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>Number of Blocks

(300A,00F0)

1

Number of shielding blocks associated with Beam.

>Total Block Tray Water-Equivalent Thickness

(300A,00F3)

3

Water-Equivalent thickness of the block tray (in mm) parallel to radiation beam axis.

>Ion Block Sequence

(300A,03A6)

1C

Sequence of blocks associated with Beam.

Required if Number of Blocks (300A,00F0) is non-zero.

The number of items shall be identical to the value of Number of Blocks (300A,00F0).

>>Block Tray ID

(300A,00F5)

3

User-supplied identifier for block tray.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

Shall not be present if Block Slab Sequence (300A,0441) is present within the same item of Ion Block Sequence (300A,03A6) or when the Block Type (300A,00F8) has a value of APERTURE and Block Slab Sequence (300A,0441) is present in another item having this value.

>>Isocenter to Block Tray Distance

(300A,00F7)

1

Isocenter to downstream edge of block tray (mm). See Section C.8.8.25.4

>>Block Type

(300A,00F8)

1

Type of block. See Section C.8.8.14.4.

Enumerated Values:

SHIELDING

blocking material is inside contour

APERTURE

blocking material is outside contour

>>Block Divergence

(300A,00FA)

1

Indicates presence or otherwise of geometrical divergence.

Enumerated Values:

PRESENT

block edges are shaped for beam divergence

ABSENT

block edges are not shaped for beam divergence

>>Block Mounting Position

(300A,00FB)

1

Indicates on which side of the Block Tray the block is mounted.

Enumerated Values:

PATIENT_SIDE

the block is mounted on the side of the Block Tray that is towards the patient

SOURCE_SIDE

the block is mounted on the side of the Block Tray that is towards the radiation source

>>Block Number

(300A,00FC)

1

Identification number of the Block. The value of Block Number (300A,00FC) shall be unique within the Beam in which it is created.

>>Block Name

(300A,00FE)

3

User-defined name for block.

>>Material ID

(300A,00E1)

2

User-supplied identifier for material used to manufacture Block.

>>Block Thickness

(300A,0100)

1

Physical thickness of block (in mm) parallel to radiation beam axis. See Section C.8.8.14.4.

>>Block Number of Points

(300A,0104)

1

Number of (x,y) pairs defining the block edge.

>>Block Data

(300A,0106)

1

A data stream of (x,y) pairs that comprise the block edge. The number of pairs shall be equal to Block Number of Points (300A,0104), and the vertices shall be interpreted as a closed polygon. Coordinates are projected onto the machine isocentric plane in the IEC BEAM LIMITING DEVICE coordinate system (mm).

>>Number of Block Slab Items

(300A,0440)

3

Number of Block Slabs comprising the Block.

Value shall be greater than 1.

>>Block Slab Sequence

(300A,0441)

1C

Sequence of slab(s) that comprise the block.

Required if Number of Block Slab Items (300A,0440) is present.

Shall be present only in the first Item of Ion Block Sequence (300A,03A6) if multiple Items are present where Block Type (300A,00F8) has a value of APERTURE.

If this Sequence is present, Accessory Code (300A,00F9) shall not be present within the same Item of Ion Block Sequence (300A,03A6).

The number of Items included in this Sequence shall equal the value of Number of Block Slab Items (300A,0440).

>>>Block Slab Number

(300A,0443)

1

Identification number of the Block Slab.

The value shall start at 1, and increase monotonically by 1.

The number indicates the order of the slabs with respect to the source, where number 1 corresponds to the slab nearest to the source.

>>>Block Slab Thickness

(300A,0442)

3

Physical thickness of block slab (in mm) parallel to radiation beam axis.

The sum of the Block Slab Thickness (300A,0442) values of all Items of this Sequence shall be equal to the Block Thickness (300A,0100) of the block.

>>>Accessory Code

(300A,00F9)

3

Machine-readable identifier for this accessory.

>Snout Sequence

(300A,030C)

3

Sequence of Snouts associated with Beam.

Only a single item is permitted in this Sequence.

>>Snout ID

(300A,030F)

1

User or machine supplied identifier for Snout.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>Applicator Sequence

(300A,0107)

3

Sequence of Applicators associated with Beam.

Only a single item is permitted in this Sequence.

>>Applicator ID

(300A,0108)

1

User or machine supplied identifier for Applicator.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>>Applicator Type

(300A,0109)

1

Type of applicator.

Defined Terms:

ION_SQUARE

square ion applicator

ION_RECT

rectangular ion applicator

ION_CIRC

circular ion applicator

ION_SHORT

short ion applicator

ION_OPEN

open (dummy) ion applicator

INTRAOPERATIVE

intraoperative (custom) applicator

STEREOTACTIC

stereotactic applicator

>>Applicator Description

(300A,010A)

3

User-defined description for Applicator.

>General Accessory Sequence

(300A,0420)

3

Introduces a Sequence of General Accessories associated with this Beam.

One or more Items are permitted in this Sequence.

>>General Accessory Number

(300A,0424)

1

Identification Number of the General Accessory. The value shall be unique within the sequence.

>>General Accessory ID

(300A,0421)

1

User or machine supplied identifier for General Accessory.

>>General Accessory Description

(300A,0422)

3

User supplied description of General Accessory.

>>General Accessory Type

(300A,0423)

3

Specifies the type of accessory.

Defined Terms:

GRATICULE

Accessory tray with a radio-opaque grid

IMAGE_DETECTOR

Image acquisition device positioned in the beam line

RETICLE

Accessory tray with radio-transparent markers or grid

>>Accessory Code

(300A,00F9)

3

Machine-readable identifier for this accessory

>>Source to General Accessory Distance

(300A,0425)

3

Radiation source to general accessory distance (in mm) for current accessory.

>Number of Range Shifters

(300A,0312)

1

Number of range shifters associated with current beam.

>Range Shifter Sequence

(300A,0314)

1C

Sequence of range shifters associated with Beam.

Required if Number of Range Shifters (300A,0312) is non-zero.

The number of items shall be identical to the value of Number of Range Shifters (300A,0312).

>>Range Shifter Number

(300A,0316)

1

Identification number of the Range Shifter. The value of Range Shifter Number (300A,0316) shall be unique within the Beam in which it is created.

>>Range Shifter ID

(300A,0318)

1

User or machine supplied identifier for Range Shifter.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>>Range Shifter Type

(300A,0320)

1

Type of Range Shifter.

Defined Terms:

ANALOG

Device is variable thickness and is composed of opposing sliding wedges, water column or similar mechanism.

BINARY

Device is composed of different thickness materials that can be moved in or out of the beam in various stepped combinations.

>>Range Shifter Description

(300A,0322)

3

User defined description of Range Shifter.

>Number of Lateral Spreading Devices

(300A,0330)

1

Number of lateral spreading devices associated with current beam.

>Lateral Spreading Device Sequence

(300A,0332)

1C

Sequence of lateral spreading devices associated with Beam.

Required if Number of Lateral Spreading Devices (300A,0330) is non-zero.

The number of items shall be identical to the value of Number of Lateral Spreading Devices (300A,0330).

>>Lateral Spreading Device Number

(300A,0334)

1

Identification number of the Lateral Spreading Device. The value of Lateral Spreading Device Number (300A,0334) shall be unique within the Beam in which it is created.

>>Lateral Spreading Device ID

(300A,0336)

1

User or machine supplied identifier for Lateral Spreading Device.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>>Lateral Spreading Device Type

(300A,0338)

1

Type of Lateral Spreading Device.

Defined Terms:

SCATTERER

metal placed into the beam path to scatter charged particles laterally.

MAGNET

nozzle configuration of magnet devices to expand beam laterally.

>>Lateral Spreading Device Description

(300A,033A)

3

User-defined description for lateral spreading device.

>Number of Range Modulators

(300A,0340)

1

Number of range modulators associated with current beam.

>Range Modulator Sequence

(300A,0342)

1C

Sequence of range modulators associated with Beam.

Required if Number of Range Modulators (300A,0340) is non-zero.

The number of items shall be identical to the value of Number of Range Modulators (300A,0340).

>>Range Modulator Number

(300A,0344)

1

Identification number of the Range Modulator. The value of Range Modulator Number (300A,0344) shall be unique within the Beam in which it is created.

>>Range Modulator ID

(300A,0346)

1

User or machine supplied identifier for Range Modulator.

>>Accessory Code

(300A,00F9)

3

An accessory identifier to be read by a device such as a bar code reader.

>>Range Modulator Type

(300A,0348)

1

Type of Range Modulator.

Defined Terms:

FIXED

fixed modulation width and weights using ridge filter or constant speed wheel with constant beam current

WHL_FIXEDWEIGHTS

selected wheel/track (Range Modulator ID) is spinning at constant speed. Modulation width is adjusted by switching constant beam current on and off at wheel steps indicated by Range Modulator Gating Values.

WHL_MODWEIGHTS

selected wheel/track (Range Modulator ID) is spinning at constant speed. Weight per wheel step is adjusted by modulating beam current according to selected Beam Current Modulation ID (300A,034C).

Only one item in the Range Modulator Sequence (300A,0342) can have a Range Modulator Type (300A,0348) of WHL_MODWEIGHTS.

>>Range Modulator Description

(300A,034A)

3

User-defined description of Range Modulator.

>>Beam Current Modulation ID

(300A,034C)

1C

User-supplied identifier for the beam current modulation pattern. Required if Range Modulator Type (300A,0348) is WHL_MODWEIGHTS

>Include Table C.8.8.28-1 “Patient Support Identification Macro Attributes”

>Fixation Light Azimuthal Angle

(300A,0356)

3

Azimuthal angle (degrees) of the fixation light coordinate around IEC BEAM LIMITING DEVICE Y-axis. Used for eye treatments. See Section C.8.8.25.6.4.

>Fixation Light Polar Angle

(300A,0358)

3

Polar angle (degrees) of the fixation light coordinate. Used for eye treatments. See Section C.8.8.25.6.4.

>Fixation Eye

(300A,0150)

3

The eye used for fixation.

Enumerated Values:

L

left eye

R

right eye

>Final Cumulative Meterset Weight

(300A,010E)

1C

Value of Cumulative Meterset Weight (300A,0134) for final Control Point in Ion Control Point Sequence (300A,03A8). Required if Cumulative Meterset Weight is non-null in Control Points specified within Ion Control Point Sequence. See Section C.8.8.14.1.

>Number of Control Points

(300A,0110)

1

Number of control points in Beam. Value shall be greater than or equal to 2.

>Ion Control Point Sequence

(300A,03A8)

1

Sequence of machine configurations describing Ion treatment beam.

The number of items shall be identical to the value of Number of Control Points (300A,0110).

See Section C.8.8.25.7.

>>Control Point Index

(300A,0112)

1

Index of current Control Point, starting at 0 for first Control Point.

>>Cumulative Meterset Weight

(300A,0134)

2

Cumulative weight to current control point. Cumulative Meterset Weight for the first item in Control Point Sequence shall always be zero. Cumulative Meterset Weight for the final item in Ion Control Point Sequence shall always be equal to Final Cumulative Meterset Weight.

>>Referenced Dose Reference Sequence

(300C,0050)

3

Introduces a sequence of Dose References for current Beam.

One or more Items are permitted in this Sequence.

>>>Referenced Dose Reference Number

(300C,0051)

1

Uniquely identifies Dose Reference specified by Dose Reference Number (300A,0012) in Dose Reference Sequence (300A,0010) in RT Prescription Module.

>>>Cumulative Dose Reference Coefficient

(300A,010C)

2

Coefficient used to calculate cumulative dose contribution from this Beam to the referenced Dose Reference at the current Control Point.

>>Nominal Beam Energy

(300A,0114)

1C

Nominal Beam Energy at control point in MeV per nucleon. Defined at nozzle entrance before all Beam Modifiers. Required for first item of Control Point Sequence, or if Nominal Beam Energy changes during Beam, and KVP (0018,0060) is not present.

>>KVP

(0018,0060)

1C

Peak kilo voltage output of the setup X-Ray generator to be used. Required for first item of Control Point Sequence, or if kVp changes during setup, and Nominal Beam Energy (300A,0114) is not present.

>>Meterset Rate

(300A,035A)

3

Specifies the speed of delivery of the specified dose in units specified by Primary Dosimeter Unit (300A,00B3) per minute.

>>Ion Wedge Position Sequence

(300A,03AC)

1C

Sequence of Wedge positions for current control point.

Required for first item of Ion Control Point Sequence if Number of Wedges (300A,00D0) is non-zero, and in subsequent control points if Wedge Position (300A,0118) or Wedge Thin Edge Position (300A,00DB) changes during beam.

The number of items shall be identical to the value of Number of Wedges (300A,00D0).

>>>Referenced Wedge Number

(300C,00C0)

1

Uniquely references Wedge described by Wedge Number (300A,00D2) in Wedge Sequence (300A,00D1).

>>>Wedge Position

(300A,0118)

1

Position of Wedge at current Control Point.

Enumerated Values:

IN

OUT

>>>Wedge Thin Edge Position

(300A,00DB)

1C

Closest distance from the central axis of the beam along a wedge axis to the thin edge as projected to the machine isocentric plane (mm). Value is positive is the wedge does not cover the central axis, negative if it does. Required if Wedge Type (300A,00D3) of the wedge referenced by Referenced Wedge Number (300C,00C0) is PARTIAL_STANDARD or PARTIAL_MOTORIZ. See Section C.8.8.25.6.4.

>>Range Shifter Settings Sequence

(300A,0360)

1C

Sequence of Range Shifter settings for the current control point.

One or more Items shall be included in this Sequence.

Required for first item of Control Point Sequence if Number of Range Shifters (300A,0312) is non-zero, or if Range Shifter Setting (300A,0362) changes during Beam.

>>>Referenced Range Shifter Number

(300C,0100)

1

Uniquely references Range Shifter described by Range Shifter Number (300A,0316) in Range Shifter Sequence (300A,0314).

>>>Range Shifter Setting

(300A,0362)

1

Machine specific setting attribute for the range shifter. The specific encoding of this value should be documented in a Conformance Statement. See Section C.8.8.25.5.

>>>Isocenter to Range Shifter Distance

(300A,0364)

3

Isocenter to downstream edge of range shifter (mm) at current control point. See Section C.8.8.25.4

>>>Range Shifter Water Equivalent Thickness

(300A,0366)

3

Water equivalent thickness (in mm) of the range shifter at the central axis for the beam energy incident upon the device.

>>Lateral Spreading Device Settings Sequence

(300A,0370)

1C

Sequence of Lateral Spreading Device settings for the current control point.

One or more Items shall be included in this Sequence.

Required for first item of Control Point Sequence if Number of Lateral Spreading Devices (300A,0330) is non-zero, or if Lateral Spreading Device Setting (300A,0372) changes during Beam.

>>>Referenced Lateral Spreading Device Number

(300C,0102)

1

Uniquely references Lateral Spreading Device described by Lateral Spreading Device Number (300A,0334) in Lateral Spreading Device Sequence (300A,0332).

>>>Lateral Spreading Device Setting

(300A,0372)

1

Machine specific setting attribute for the lateral spreading device. The specific encoding of this value should be documented in a Conformance Statement. See Section C.8.8.25.5.

>>>Isocenter to Lateral Spreading Device Distance

(300A,0374)

3

Isocenter to downstream edge of Lateral Spreading Device (mm) at current control point. See Section C.8.8.25.4

>>>Lateral Spreading Device Water Equivalent Thickness

(300A,033C)

3

Water equivalent thickness (in mm) of the lateral spreading device at the central axis for the beam energy incident upon the device.

>>Range Modulator Settings Sequence

(300A,0380)

1C

Sequence of Range Modulator Settings for current control point.

One or more Items shall be included in this Sequence.

Required for first item of Control Point Sequence if Number of Range Modulators (300A,0340) is non-zero, or if Range Modulator Setting changes during Beam.

>>>Referenced Range Modulator Number

(300C,0104)

1

Uniquely references Range Modulator described by Range Modulator Number (300A,0344) in Range Modulator Sequence (300A,0342).

>>>Range Modulator Gating Start Value

(300A,0382)

1C

Start position defines the range modulator position at which the beam is switched on. Required if Range Modulator Type (300A,0348) of the range modulator referenced by Referenced Range Modulator Number (300C,0104) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS

>>>Range Modulator Gating Stop Value

(300A,0384)

1C

Stop position defines the range modulator position at which the beam is switched off. Required if Range Modulator Type (300A,0348) of the range modulator referenced by Referenced Range Modulator Number (300C,0104) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS

>>>Range Modulator Gating Start Water Equivalent Thickness

(300A,0386)

3

If Range Modulator Type (300A,0348) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS:

Water equivalent thickness (in mm) of the range modulator at the position specified by Range Modulator Gating Start Value (300A,0382).

If Range Modulator Type (300A,0348) is FIXED:

Minimum water equivalent thickness (in mm) of the range modulator.

>>>Range Modulator Gating Stop Water Equivalent Thickness

(300A,0388)

3

If Range Modulator Type (300A,0348) is WHL_MODWEIGHTS or WHL_FIXEDWEIGHTS:

Water equivalent thickness (in mm) of the range modulator at the position specified by Range Modulator Gating Stop Value (300A,0384).

If Range Modulator Type (300A,0348) is FIXED:

Maximum water equivalent thickness (in mm) of the range modulator.

>>>Isocenter to Range Modulator Distance

(300A,038A)

3

Isocenter to downstream edge of range modulator (mm) at current control point. See Section C.8.8.25.4

>>Include Table C.8.8.27-1 “Beam Limiting Device Position Macro Attributes”

>>Gantry Angle

(300A,011E)

1C

Gantry angle of radiation source, i.e., orientation of IEC GANTRY coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Angle changes during Beam.

>>Gantry Rotation Direction

(300A,011F)

1C

Direction of Gantry Rotation when viewing gantry from isocenter, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Gantry Pitch Angle

(300A,014A)

2C

Gantry Pitch Angle of the radiation source, i.e., the rotation of the IEC GANTRY coordinate system about the X-axis of the IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Gantry Pitch Rotation Angle changes during Beam. See Section C.8.8.25.6.5.

>>Gantry Pitch Rotation Direction

(300A,014C)

2C

Direction of Gantry Pitch Angle when viewing along the positive X-axis of the IEC GANTRY coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Gantry Pitch Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.5.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Beam Limiting Device Angle

(300A,0120)

1C

Beam Limiting Device angle, i.e., orientation of IEC BEAM LIMITING DEVICE coordinate system with respect to IEC GANTRY coordinate system (degrees). Required for first item of Control Point Sequence, or if Beam Limiting Device Angle changes during Beam.

>>Beam Limiting Device Rotation Direction

(300A,0121)

1C

Direction of Beam Limiting Device Rotation when viewing beam limiting device (collimator) from radiation source, for segment following Control Point. Required for first item of Control Point Sequence, or if Beam Limiting Device Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Scan Spot Tune ID

(300A,0390)

1C

User-supplied or machine code identifier for machine configuration to produce beam spot. This may be the nominal spot size or some other machine specific value. Required if Scan Mode (300A,0308) is MODULATED or MODULATED_SPEC.

>>Scan Spot Reordering Allowed

(300A,0395)

3

Indicates whether the spot delivery order shall remain the same as planned order.

Enumerated Values:

ALLOWED

The delivery device may deliver the spots in any order

NOT ALLOWED

The delivery device shall not change the order of the spots within the map and must deliver them in the prescribed order.

>>Number of Scan Spot Positions

(300A,0392)

1C

Number of spot positions used to specify scanning pattern for current segment beginning at control point. Required if Scan Mode (300A,0308) is MODULATED or MODULATED_SPEC.

>>Scan Spot Position Map

(300A,0394)

1C

A data stream of (x,y) pairs that define the coordinates of the scan spots as projected onto the machine isocentric plane in the IEC GANTRY coordinate system (mm). Required if Scan Mode (300A,0308) is MODULATED or MODULATED_SPEC. Contains 2N values where N is the Number of Scan Spot Positions (300A,0392). See Section C.8.8.25.8.

>>Scan Spot Meterset Weights

(300A,0396)

1C

A data set of Meterset weights corresponding to scan spot positions. The order of weights matches the positions in Scan Spot Positions (300A,0394). The sum contained in all Meterset weights shall match the difference of the cumulative Meterset weight of the current control point to the following control point. Required if Scan Mode (300A,0308) is MODULATED or MODULATED_SPEC. See Section C.8.8.25.8

>>Scanning Spot Size

(300A,0398)

3

The Scanning Spot Size as calculated using the Full Width Half Maximum (FWHM). Specified by a numeric pair - the size measured in air at isocenter in IEC GANTRY X direction followed by the size in the IEC GANTRY Y direction (mm).

>>Number of Paintings

(300A,039A)

1C

The number of times the scan pattern given by Scan Spot Position Map (300A,0394) and Scan Spot Meterset Weights (300A,0396) shall be applied at the current control point. To obtain the Meterset weight per painting, the values in the Scan Spot Meterset Weights (300A,0396) should be divided by the value of this attribute. Required if Scan Mode (300A,0308) is MODULATED or MODULATED_SPEC.

>>Patient Support Angle

(300A,0122)

1C

Patient Support angle, i.e., orientation of IEC PATIENT SUPPORT (turntable) coordinate system with respect to IEC FIXED REFERENCE coordinate system (degrees). Required for first item of Control Point Sequence, or if Patient Support Angle changes during Beam.

>>Patient Support Rotation Direction

(300A,0123)

1C

Direction of Patient Support Rotation when viewing table from above, for segment following Control Point. Required for first item of Control Point Sequence, or if Patient Support Rotation Direction changes during Beam. See Section C.8.8.14.8.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Pitch Angle

(300A,0140)

2C

Table Top Pitch Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the X-axis of the IEC TABLE TOP coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Pitch Angle changes during Beam. See Section C.8.8.25.6.2.

>>Table Top Pitch Rotation Direction

(300A,0142)

2C

Direction of Table Top Pitch Rotation when viewing the table along the positive X-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Pitch Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.2.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Roll Angle

(300A,0144)

2C

Table Top Roll Angle, i.e., the rotation of the IEC TABLE TOP coordinate system about the Y-axis of the IEC TABLE TOP coordinate system (degrees). Required for first item of Control Point Sequence, or if Table Top Roll Angle changes during Beam. See Section C.8.8.25.6.2.

>>Table Top Roll Rotation Direction

(300A,0146)

2C

Direction of Table Top Roll Rotation when viewing the table along the positive Y-axis of the IEC TABLE TOP coordinate system, for segment following Control Point. Required for first item of Control Point Sequence, or if Table Top Roll Rotation Direction changes during Beam. See Section C.8.8.14.8 and Section C.8.8.25.6.2.

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation.

>>Head Fixation Angle

(300A,0148)

3

Angle (in degrees) of the head fixation for eye treatments with respect to the Table Top Pitch Angle (300A,0140) coordinate system. Positive head fixation angle is the same direction as positive Table Top pitch. See Section C.8.8.25.6.4.

>>Chair Head Frame Position

(300A,0151)

3

A device-specific value that specifies the relationship between the chair in which the patient is sitting and the head frame in which their head is fixed.

It shall be expressed as a distance in mm, such that positive is towards the patient's head away from the seat.

Note

This value is not intended to be used for geometric calculations, however, for the same device, the relative distance is meaningful.

Typically used for eye treatments.

>>Table Top Vertical Position

(300A,0128)

2C

Table Top Vertical position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Vertical Position changes during Beam. See Section C.8.8.14.6.

>>Table Top Longitudinal Position

(300A,0129)

2C

Table Top Longitudinal position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Longitudinal Position changes during Beam. See Section C.8.8.14.6.

>>Table Top Lateral Position

(300A,012A)

2C

Table Top Lateral position in IEC TABLE TOP coordinate system (mm). Required for first item of Control Point Sequence, or if Table Top Lateral Position changes during Beam. See Section C.8.8.14.6.

>>Snout Position

(300A,030D)

2C

Axial position of the snout (in mm) measured from isocenter to the downstream side of the snout (without consideration of variable length elements such as blocks, MLC and/or compensators). Required for first item in Control Point Sequence, or if Snout Position changes during Beam.

>>Isocenter Position

(300A,012C)

2C

Isocenter coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm). Required for first item of Segment Control Point Sequence, or if Segment Isocenter Position changes during Beam.

>>Surface Entry Point

(300A,012E)

3

Patient surface entry point coordinates (x,y,z), along the central axis of the beam, in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).

>>External Contour Entry Point

(300A,0133)

3

External Contour entry point coordinates (x,y,z) in the patient based coordinate system described in Section C.7.6.2.1.1 (mm).

See Section C.8.8.14.15.


C.8.8.25.1 Beam Identifying Information

Beam Number (300A,00C0) is provided to link related information across modules, and its value has no real-world interpretation. Beam Name (300A,00C2), a Type 1 attribute, is intended to store the primary beam identifier (often referred to as "Field ID"). Beam Description (300A,00C3), a Type 3 attribute, is intended to store additional beam identifying information (often referred to as "Field Name").

C.8.8.25.2 Treatment Machine Name

The DICOM standard does not support the transmission of treatment unit modeling information such as depth doses and beam profiles. In the case of Ion therapy, the Treatment Machine Name attribute is used to uniquely identify a treatment port (or beam line), since there is in effect only one treatment machine (i.e., synchrotron).

C.8.8.25.3 Leaf Position Boundaries

The Leaf Position Boundaries (300A,00BE) shall be the positions of the mechanical boundaries (projected to the isocentric plane) between beam limiting device (collimator) leaves, fixed for a given beam limiting device (collimator). Leaf/Jaw positions (300A,011C) are values specific to a given control point, specifying the beam limiting device (collimator) leaf (element) openings.

In an RT Ion Plan, the Virtual SAD can have different values along the X/Y axes (see Section C.8.8.25.4). Thus the effects of possibly different X/Y SADs shall be taken into account when leaf position boundaries and leaf/jaw positions are projected from the virtual source to the plane of isocenter.

Leaf Position Boundaries (300A,00BE), are outside the control point sequence, which may define a collimator rotation. Therefore their values shall be defined for a collimator angle of 0 Deg IEC nominal position). For rotated collimators, the leaf position calculation is as follows: Define Mx and My as the magnification factors for the scaling of the leaf positions from their real space position to the isocenter plane. Mx and My are calculated from the virtual SADs VSADx or VSADy, respectively, and the Isocenter to Beam Limiting Device Distance (300A,00BB).

The magnification factor Mα for an arbitrary beam limiting device angle a then becomes:

Snout Position (300A,030D) may be changed between beams, and possibly between control points as well. This results in different effective isocenter to beam limiting device distances and thus leaf position boundaries for the same physical beam limiting device for each beam and possibly control points.

The values for Beam Limiting Device Distances (300A,00BB) and Leaf Position Boundaries (300A,00BE) are defined outside the control point sequence. Therefore the Isocenter to Beam Limiting Device Distance (300A,00BB) and the Leaf Position Boundaries (300A,00BE) shall be defined to apply to the first control point of the respective beam. If the snout position changes for subsequent control points, this must be taken into account for the projection of the leaf/jaw positions (i.e., replace IsocenterToBeamLimitingDeviceDistance in the above formula by the effective distance as calculated from the shift in snout position).

C.8.8.25.4 Virtual Source-Axis Distances and the Use of Trays in Ion Therapy

The apparent source position in ion therapy is not constant or can be different in x or y direction. The apparent source position (as measured from field size projections) shall be called Virtual Source, the distance from the virtual source to isocenter the Virtual SAD.

Most of the cases, no trays are used for blocks, compensators and wedges. However, the concept of trays together with the mounting position is useful for specifying exactly at which point the position of these devices shall be measured. Therefore, trays shall always be present, even though they are only virtual trays.

Figure C.8.8.25-1 shows an example.

Figure C.8.8.25-1. Virtual Source-Axis Distances


Examples: The use of the above attributes for snout positioning and block/compensator manufacturing:

  1. Snout positioning:

    The mounting positions as depicted in the drawing are only examples. As the block tray does not really exist in most of the cases, it is only used as a reference position. As some machines use the downstream face of the block as a reference position for their snout positioning, it could make sense to define for example that the block mounting position must be SOURCE_SIDE. In this case, one uses the downstream face of the block as the reference position, which is the same side as used by the machine. This definition is always independent of the actual thickness of the block. The Isocenter-Block Distance is defined and the machine can deduce the position of the snout from this value.

  2. Scaling of block/compensator data for manufacturing

    The Isocenter position is always used as the reference position for all distances measured 'from isocenter'. Real size block and compensator manufacturing should be based on the distance from the Virtual Source (X/Y) to the device, i.e., VirtualSourceToDeviceDistance = VirtualSAD - IsocenterToDeviceDistance.

C.8.8.25.5 Range Shifter and Lateral Spreading Device Settings

The Range Shifter and Lateral Spreading Device Settings attributes are used to capture machine specific values related to these devices. For example, some machines may specify the Range Shifter setting as the desired Water-Equivalent Thickness (in mm). Others contain a series of interchangeable plates, whose position in or out of the beam is specified by a series of ones and zeros (i.e., 100010 would specify that plates #1 and #5 are in the beam. If the device does not a specific setting, but rather is defined by the ID, then the Enumerated Values IN/OUT shall be used for the setting.

C.8.8.25.6 Coordinate Systems

Where explicitly specified, the coordinate systems defined by IEC 61217 shall be applied, with the exception of the IEC Patient Coordinate System.

In addition, the following sections define the coordinate systems to be used in situations where IEC 61217 coordinate systems are not applicable. No other coordinate systems shall be used.

C.8.8.25.6.1 Fixed Beam Line

The direction of fixed beam-line can be described as a gantry system, provided that the position of the (virtual) gantry bearing is defined. The relation between their patient support coordinate system axes and the choice of the 'gantry' angle, e.g., 90 or 270 deg, shall be consistent with a standard gantry coordinate system. All coordinate systems derived from the IEC GANTRY coordinate system (BEAM LIMITING DEVICE, WEDGE, X-RAY IMAGE RECEPTOR) automatically follow in the same way as defined in a 'real' gantry system.

The IEC PATIENT SUPPORT system is linked to the IEC GANTRY coordinate system through its common parent system, the IEC FIXED coordinate system. The Y-axis of IEC GANTRY points towards the (virtual) gantry bearing. The Y-axis of the IEC FIXED coordinate system has to point in the same direction. Z-axis in IEC FIXED coordinate system is always pointing upwards. With Y and Z-axes defined, the X-axis of IEC FIXED is also given.

Figure C.8.8.25-2a and Figure C.8.8.25-2b show IEC FIXED (F), GANTRY (G) and PATIENT SUPPORT (S) coordinate systems for a horizontal fixed beam-line.

Figure C.8.8.25-2a. Fixed Beam Line - View Along IEC FIXED Y-axis


Figure C.8.8.25-2b. Fixed Beam Line - View From Top (Along IEC FIXED Z-axis)


C.8.8.25.6.2 Table Top Pitch and Table Top Roll

For further information, see Section C.8.8.14.12.

C.8.8.25.6.3 Seated Treatments

RT Ion Plan contains an attribute Patient Support Type (300A,0350), which can be CHAIR or TABLE. The patient support type CHAIR does not change the coordinate axes of the patient support coordinate systems relative to their parent systems. It is more an attribute of the type like the patient position in imaging (i.e., HFS, HFP, …).

The orientation of the treatment chair shall be defined with the chair positioned in such way, that the patient looks towards the gantry bearing (or along the Y axis of the IEC FIXED system) if all angles, especially IEC PATIENT SUPPORT angle are 0°. All other parameters follow straight forward, once this definition is accepted. i.e., chair rotation is a rotation of IEC PATIENT SUPPORT coordinate system; a backward tilt of the chair is a positive rotation of the PITCHED TABLE TOP coordinate system. A translation of the chair is a translation of the IEC TABLE TOP system.

The roll angle is typically 0º.

For a seated treatment on a horizontal beam-line, the following angles are therefore defined:If IEC GANTRY angle is 90º (270º), IEC PATIENT SUPPORT angle is 270º (90º) for the position where the patient looks into the beam port.

C.8.8.25.6.4 Ocular Treatments
C.8.8.25.6.4.1 Gantry Beam Line

Eye treatments on the gantry shall use all existing IEC coordinate systems with their standard definition. This applies especially to IEC BEAM LIMITING DEVICE, IEC WEDGE FILTER, IEC X-RAY IMAGE RECEPTOR.

IEC PATIENT SUPPORT, and IEC TABLE TOP coordinate systems are defined as above. Additionally, a rotation of the head fixation device is possible. The Head Fixation Angle (300A,0148) shall be defined as the angle of the head fixation device with respect to the TABLE TOP coordinate system. Positive head fixation angle is in the same direction as positive PATIENT SUPPORT pitch, i.e., backwards.

Proton eye treatments require an additional coordinate system for the placement of the fixation light. Since it is usually mounted onto the beam port the 'natural' coordinate system for devices mounted there is the IEC BEAM LIMITING DEVICE coordinate system. The angles for the fixation light positions shall therefore be defined as follows:

Rotation of the fixation light about the IEC BEAM LIMITING DEVICE Z-axis (Zb) is defined as Azimuthal Angle. The Azimuthal Angle is equal to 0° when the fixation light is positioned on the axis Xb of the IEC BEAM LIMITING DEVICE coordinate system. An increase in the value of the Azimuthal Angle corresponds to clockwise rotation of the fixation light as view along the axis Zb towards the virtual source.

The polar angle is always positive and defined as the angle between IEC BEAM LIMITING DEVICE Z-axis and the line connecting isocenter with the fixation light position.

Proton eye treatments require the wedge thin edge position as one additional. The wedge thin edge position allows the specification of a wedge, which does not cover the full open field. The wedge thin edge position is positive, if the wedge does not cover the isocenter position and negative, if it does cover.

Figure C.8.8.25-5 and Figure C.8.8.25-6 show the angles and attributes as described above.

Figure C.8.8.25-5. Patient's eye view


Figure C.8.8.25-6. Lateral view along the positive axis Xb


C.8.8.25.6.4.2 Fixed Beam Line

The coordinate systems for the treatment chair are defined above and shall also be applied to seated eye treatments.

In this case, it is recommended that a beam limiting device angle of 90º be formally applied (provided the gantry angle is defined to be 90º (and not 270º). This results in the same coordinates of the fixation light and wedge relative to the patient as in the treatment situation with the patient lying on the table.

C.8.8.25.6.5 Gantry Pitch Angle

The Gantry Pitch Angle is not defined in IEC 61217. This angle is defined in the DICOM standard in a way compatible with the current notion of IEC by introducing it as rotation of the IEC GANTRY System as indicated below.

The Gantry Pitch Angle is defined as the rotation of the coordinate axes Yg, Zg about axis Xg by an angle ψg; See Figure C.8.8.25-7. An increase in the value of angle ψg corresponds to the clockwise rotation as viewed from the isocenter along the positive Xg axis

Figure C.8.8.25-7. Gantry Pitch Angle


C.8.8.25.7 Ion Control Point Sequence

The control point sequence for RT Ion Beams is defined using the same rule set as in the RT Beams Module (see Section C.8.8.14.5). Specifically, the following rules apply:

  • All parameters that change at any control point of a given beam shall be specified explicitly at all control points (including those preceding the change).

  • All parameters of an irradiation segment (i.e., with values of the Cumulative Meterset Weight (300A,0134) different at the beginning and at the end of the segment) shall therefore be specified in 2 separate control points denoting the beginning and at the end of this segment. Each irradiation segment is therefore represented by 2 control points.

  • Parameters changing during the segment shall be represented by their different values at those control points. Parameters that do not change during the segment shall be represented with equal values at both control points (unless they are constant for all control points of the beam). For example, a beam delivery involving two independent irradiation segments will require 4 control points. Control Points 0 and 1 define the first irradiation segment. Between control points 1 and 2, no radiation is given (Meterset is constant), but other parameters may change. Finally, the second irradiation segment occurs between control points 2 and 3.

This definition allows unambiguous and explicit determination of those parameters changing while irradiation is occurring, as opposed to those parameters that change between irradiation segments. No assumptions are made about the behavior of machine parameters between specified control points, and communicating devices shall agree on this behavior outside the standard.

The following example illustrates this rule (not all parameters are shown), in the case of a scanning beam with 2 segments and Total Cumulative Meterset of 70.

Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight = 0 Nominal Energy: 200 Scan Spot Position Map: -40, -35, -40, -30 (Positions for 1st segment) Scan Spot Meterset Weight: 0.5, 0.3, 1.2, (Values add up to Meterset difference between Control Points 0 and 1)

Control Point 1: All applicable treatment parameters defined, Cumulative Meterset Weight = 30.0 Nominal Energy: 200 Scan Spot Position Map: -40, -35, -40, -30 (Positions for 1st segment) Scan Spot Meterset Weight:0.0, 0.0, 0.0, … (All values are 0.0, because Meterset Weight difference between Control Point 1 and 2 is 0.0)

Control Point 2: All applicable treatment parameters defined, Cumulative Meterset Weight = 30.0 Nominal Energy: 180 Scan Spot Position Map: -55, -40, -55, -35, (Positions for 2nd segment) Spot Meterset Weight: 0.7, 0.8, 1.5 (Values add up to Meterset difference between Control Points 2 and 3)

Control Point 3: All applicable treatment parameters defined, Cumulative Meterset Weight = 70.0 Nominal Energy: 180 Scan Spot Position Map: -55, -40, -55, -35, (Positions for 2nd segment) Spot Meterset Weight: 0.0, 0.0, 0.0, (All values are 0.0, because there is no following control point (end of sequence).

C.8.8.25.8 Scan Spot Maps

The Scan Spot Position Map (300A,0394) and Scan Spot Meterset Weights (300A,0396) shall be used as follows.

The following specifies for each value of Modulated Scan Mode Type (300A,0309) the definition of the map which is included in the Control Point 1 having Cumulative Meterset Weight (300A,0134) = 20, followed by a Control Point 2 having Cumulative Meterset Weight(300A,0134) = 20.

If Modulated Scan Mode Type (300A,0309) is STATIONARY or LEAPING:

Position (X,Y)

(1.0, 2.0)

(3.0, 2.0)

(5.0, 2.0)

(7.0, 2.0)

(9.0, 2.0)

Meterset Weights

5

4

6

2

3

Delivery Description:

  • The beam is positioned at Scan Spot Position (1.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 5.

  • The beam is switched off or quickly moved and positioned at Scan Spot Position (3.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 4.

  • The beam is switched off or quickly moved and positioned at Scan Spot Position (5.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 6.

  • The beam is switched off or quickly moved and positioned at Scan Spot Position (7.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 2.

  • The beam is switched off or quickly moved and positioned at Scan Spot Position (9.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 3.

If Modulated Scan Mode Type (300A,0309) is LINEAR:

Position (X,Y)

(1.0, 2.0)

(3.0, 2.0)

(5.0, 2.0)

(7.0, 2.0)

(9.0, 2.0)

Meterset Weights

0

4

6

7

3

Delivery Description:

  • The beam is positioned at Scan Spot Position (1,.0 2.0).

  • The beam is continuously delivered with a Cumulative Meterset Weight of 4, while being moved from Scan Spot Position (1.0, 2.0) to Scan Spot Position (3.0, 2.0).

  • The beam is continuously delivered with a Cumulative Meterset Weight of 6, while being moved from Scan Spot Position (3.0, 2.0) to Scan Spot Position (5.0, 2.0).

  • The beam is continuously delivered with a Cumulative Meterset Weight of 7, while being moved from Scan Spot Position (5.0, 2.0) to Scan Spot Position (7.0, 2.0).

  • The beam is continuously delivered with a Cumulative Meterset Weight of 3, while being moved from Scan Spot Position (7.0, 2.0) to Scan Spot Position (9.0, 2.0).

If Modulated Scan Mode Type (300A,0309) is MIXED:

Position (X,Y)

(1.0, 2.0)

(1.0, 2.0)

(3.0, 2.0)

(5.0, 2.0)

(5.0, 2.0)

(7.0, 2.0)

(7.0, 2.0)

Meterset Weights

0

4

6

5

2

0

3

Delivery Description:

  • The beam is positioned at Scan Spot Position (1.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 4 while staying at Scan Spot Position (1.0, 2.0).

  • The beam is continuously delivered with a Cumulative Meterset Weight of 6, while being moved from Scan Spot Position (1.0, 2.0) to Scan Spot Position (3.0, 2.0).

  • The beam is continuously delivered with a Cumulative Meterset Weight of 5, while being moved from Scan Spot Position (3.0, 2.0) to Scan Spot Position (5.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 2 while staying at Scan Spot Position (5.0, 2.0).

  • The beam is switched off or quickly moved and positioned at Scan Spot Position (7.0, 2.0).

  • The beam is delivered with a Cumulative Meterset Weight of 3 while staying at Scan Spot Position (7.0, 2.0).

C.8.8.25.9 Depth Dose Parameters Sequence Attributes

Some delivery systems determine the settings of the range shifter (or beam energy) and range modulators internally based upon clinical parameters.

The attributes mentioned in this section represent those clinical parameters.

When the Depth Dose Parameters Sequence (300A,0505) is present, those specifications have precedence over the definitions of the Range Shifters defined in Range Shifter Settings Sequence (300A,0360) and the Range Modulator defined in Range Modulator Settings Sequence (300A,0380).

The following three figures explain the use of the Range Modulated Region attributes.

Figure C.8.8.25.9-1 shows an example of those attributes with the following values:

  • Nominal Range Modulated Region Depths (300A,0504) = 147\298

  • Reference Dose Definition (300A,0512) = CENTER

  • Distal Depth (300A,0502) = 301

  • Distal Depth Fraction (300A,0501) = 0.9

  • Nominal Range Modulation Fractions (300A,0503) = 0.95\0.98

Figure C.8.8.25.9-1. Attributes specifying a depth dose distribution parameters in case of Reference Dose Definition (300A,0512) = CENTER


Figure C.8.8.25.9-2 is an expansion of the steep-gradient part of the depth dose curve for better readability of the parameters annotating this part.

Figure C.8.8.25.9-2. Attributes specifying a generic depth dose distribution. Abscissa expanded near distal edge of dose distribution.


Defined Terms for Reference Dose Definition (300A,0512):

HIGHEST

The maximum dose for the highest energy of the non-range modulated component is used for determining the fractions.

MAXIMUM

The maximum dose of the range modulated depth dose distribution is used for determining the fractions.

CENTER

The dose measured at the center of the range modulated region of the depth dose distribution is used for determining the fractions.

Figure C.8.8.25.9-3 shows the usage of the Defined Terms of Reference Dose Definition (300A,0512).

In Figure C.8.8.25.9-3, the modulated region is defined the same as in Figure C.8.8.25.9-1:

  • Nominal Range Modulated Region Depths (300A,0504) = (147\298)

In this example, the 100% reference level for the dose definition is determined for the Defined Terms specified in Reference Dose Definition (300A,0512) as follows:

HIGHEST

The maximum dose for the highest energy of the non-range modulated component is located at 304 mm and used for determining the fractions.

MAXIMUM

The maximum dose of the range modulated depth dose distribution is located at 300 mm and used for determining the fractions.

CENTER

The dose measured at 220 mm depth at the center of the range modulated region of the depth dose distribution is used for determining the fractions.

Figure C.8.8.25.9-3. Representation of the different Reference Dose Definition (300A,0512) using the range modulated depth dose distribution or highest energy component depth dose distribution.