Referenced Beam Number Attribute
| Tag | (300C,0006) |
|---|---|
| Type | Required (1) |
| Keyword | ReferencedBeamNumber |
| Value Multiplicity | 1 |
| Value Representation | Integer String (IS) |
References Beam specified by Beam Number (300A,00C0) in Ion Beam Sequence (300A,03A2) in RT Ion Beams Module within the referenced RT Ion Plan.
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 |
Attribute 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. |
|
>Entity Long Label |
(3010,0038) |
3 |
User-defined label 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:
|
|
>Radiation Type |
(300A,00C6) |
1 |
Particle type of Beam. Defined Terms:
|
|
>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:
|
|
>Modulated Scan Mode Type |
(300A,0309) |
1C |
Defines the specialization of a modulated scan mode. Defined Terms:
NoteThe Defined Term MIXED was previously defined. It is now retired. 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. |
|
>Institutional Department Type Code Sequence |
(0008,1041) |
3 |
A coded description of the type of Department or Service within the healthcare facility. Only a single Item is permitted in this Sequence. |
|
>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. |
|
>Date of Manufacture |
(0018,1204) |
3 |
The date the equipment that is to be used for treatment delivery was originally manufactured or re-manufactured (as opposed to refurbished). |
|
>Date of Installation |
(0018,1205) |
3 |
The date the equipment that is to be used for treatment delivery was installed in its current location. The equipment may or may not have been used prior to installation in its current location. |
|
>Primary Dosimeter Unit |
(300A,00B3) |
1 |
Measurement unit of machine dosimeter. Enumerated Values:
|
|
>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:
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. |
|
>Enhanced RT Beam Limiting Device Definition Flag |
(3008,00A3) |
3 |
Whether the RT Beam Limiting Devices are specified by the Enhanced RT Beam Limiting Device Sequence (3008,00A1). Enumerated Values:
|
|
>Ion Beam Limiting Device Sequence |
(300A,03A4) |
3 |
Sequence of beam limiting device (collimator) jaw or leaf (element) sets. Shall not be present if Enhanced RT Beam Limiting Device Definition Flag (3008,00A3) is present and has the value YES. 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:
|
|
>>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 and Section C.8.8.25.10. |
|
>>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. |
|
>Enhanced RT Beam Limiting Device Sequence |
(3008,00A1) |
1C |
Enhanced RT Beam Limiting Device Descriptions. Required if Enhanced RT Beam Limiting Device Definition Flag (3008,00A3) is present and has the value YES. One or more Items shall be included in this Sequence. |
|
>>Include Table C.36.2.2.19-1 “RT Beam Limiting Device Definition Macro Attributes”. |
Device Type Code Sequence (3010,002E) within RT Accessory Device Identification Macro DCID 9540 “Movable Beam Limiting Device Type”. See Section C.8.8.25.12. |
||
|
>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:
|
|
>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:
|
|
>>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). |
|
>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 and Section C.8.8.25.10 |
|
>>Compensator Divergence |
(300A,02E0) |
1 |
Indicates presence or absence of geometrical divergence of the range compensator. Enumerated Values:
|
|
>>Compensator Mounting Position |
(300A,02E1) |
1 |
Indicates on which side of the Compensator Tray the compensator is mounted. Enumerated Values:
|
|
>>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, Section C.8.8.25.4, Section C.8.8.25.10 and Section C.8.8.25.11. |
|
>>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 identifier for the Block 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 and Section C.8.8.25.10 |
|
>>Block Type |
(300A,00F8) |
1 |
Type of block. See Section C.8.8.14.4. Enumerated Values:
|
|
>>Block Divergence |
(300A,00FA) |
1 |
Indicates presence or otherwise of geometrical divergence. Enumerated Values:
|
|
>>Block Mounting Position |
(300A,00FB) |
1 |
Indicates on which side of the Block Tray the block is mounted. Enumerated Values:
|
|
>>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). See Section C.8.8.25.11. |
|
>>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 Block Slab. |
|
>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:
|
|
>>Applicator Description |
(300A,010A) |
3 |
User-defined description for Applicator. |
|
>General Accessory Sequence |
(300A,0420) |
3 |
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:
|
|
>>Accessory Code |
(300A,00F9) |
3 |
Machine-readable identifier for this accessory. |
|
>>Isocenter to General Accessory Distance |
(300A,0426) |
3 |
Isocenter to general accessory distance (in mm) for current accessory. See Section C.8.8.25.10. |
|
>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:
|
|
>>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:
|
|
>>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:
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” |
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|
>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:
|
|
>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 |
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:
|
|
>>>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 and Section C.8.8.25.10 |
|
>>>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 and Section C.8.8.25.10 |
|
>>>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 and Section C.8.8.25.10 |
|
>>Include Table C.8.8.27-1 “Beam Limiting Device Position Macro Attributes” |
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|
>>Enhanced RT Beam Limiting Opening Sequence |
(3008,00A2) |
1C |
Sequence of beam limiting device (collimator) jaw or leaf (element) positions. Required for first Item of Control Point Sequence, or if the values of the Beam Limiting Device the Beam and if Enhanced RT Beam Limiting Device Definition Flag (3008,00A3) is present and has the value YES. One or more Items shall be included in this Sequence. The number of Items shall equal the number of Items in Enhanced RT Beam Limiting Device Sequence (3008,00A1) in the first Control Point and be equal or less in subsequent Control Points. See Section C.8.8.14.18. |
|
>>>Include Table C.36.2.2.20-1 “RT Beam Limiting Device Opening Definition Macro Attributes” |
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|
>>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:
|
|
>>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:
|
|
>>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:
|
|
>>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:
|
|
>>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 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. |
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>>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:
|
|
>>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:
|
|
>>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:
|
|
>>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. NoteThis 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 is not required to have any real-world interpretation. Beam Name (300A,00C2), a Type 1 Attribute, is intended to store the primary beam identifier (often referred to as "field identifier"). Entity Long Label (3010,0038), a Type 3 Attribute, is intended to store additional beam identifying information (often referred to as "field name"). Beam Description (300A,00C3), a Type 3 Attribute, is intended to store beam summary information (often referred to as "field note"). The Conformance Statement shall document how these Attributes are populated.
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:
-
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.
-
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 use 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:
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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).
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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.
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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 Final Cumulative Meterset Weight (300A,010E) of 70.
Control Point 0: All applicable treatment parameters defined, Cumulative Meterset Weight (300A,0134) = 0 Nominal Energy: 200 Scan Spot Position Map: (-40, -35), (-40, -30) [Positions for 1st segment] Scan Spot Meterset Weight: 10, 20. Values add up to Meterset difference between Control Points 0 and 1.
Control Point 1: All applicable treatment parameters defined, Cumulative Meterset Weight (300A,0134) = 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. All values are 0.0, because the Cumulative Meterset Weight difference between Control Point 1 and 2 is 0.0.
Control Point 2: All applicable treatment parameters defined, Cumulative Meterset Weight (300A,0134) = 30.0 Nominal Energy: 180 Scan Spot Position Map: (-55, -40), (-55, -35) [Positions for 2nd segment] Scan Spot Meterset Weight: 25, 15. Values add up to the Cumulative Meterset Weight difference between Control Points 2 and 3.
Control Point 3: All applicable treatment parameters defined, Cumulative Meterset Weight (300A,0134) = 70.0 Nominal Energy: 180 Scan Spot Position Map: (-55, -40), (-55, -35) [Positions for 2nd segment] Scan Spot Meterset Weight: 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.
For a Modulated Scan Mode Type (300A,0309) value of LEAPING or LINEAR, switching off the beam shall be prescribed and reported using a Meterset Weight of zero at the next Scan Spot Position.
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) = 40.
If Modulated Scan Mode Type (300A,0309) is STATIONARY:
|
Position (X,Y) |
(1.0, 2.0) |
(6.0, 2.0) |
(6.0, 3.0) |
(2.0, 3.0) |
(2.0, 5.0) |
(7.0, 5.0) |
|---|---|---|---|---|---|---|
|
Meterset Weights |
2 |
6 |
1 |
5 |
3 |
3 |
Delivery Description:
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The beam is positioned at Scan Spot Position (1.0, 2.0).
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The beam is delivered with a Meterset Weight of 2.
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The beam is switched off and positioned at Scan Spot Position (6.0, 2.0).
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The beam is delivered with a Meterset Weight of 6.
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The beam is switched off and positioned at Scan Spot Position (6.0, 3.0).
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The beam is delivered with a Meterset Weight of 1.
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The beam is switched off and positioned at Scan Spot Position (2.0, 3.0).
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The beam is delivered with a Meterset Weight of 5.
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The beam is switched off and positioned at Scan Spot Position (2.0, 5.0).
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The beam is delivered with a Meterset Weight of 3.
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The beam is switched off and positioned at Scan Spot Position (7.0, 5.0).
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The beam is delivered with a Meterset Weight of 3.
If Modulated Scan Mode Type (300A,0309) is LEAPING:
|
Position (X,Y) |
(1.0, 2.0) |
(6.0, 2.0) |
(6.0, 3.0) |
(2.0, 3.0) |
(7.0, 5.0) |
(7.0, 5.0) |
|---|---|---|---|---|---|---|
|
Meterset Weights |
1 |
5 |
4 |
6 |
0 |
4 |
Delivery Description:
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The beam is positioned at Scan Spot Position (1.0, 2.0).
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The beam is delivered with a Meterset Weight of 1.
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The beam is moved and positioned at Scan Spot Position (6.0, 2.0).
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The beam is delivered until a Meterset Weight of 5 is reached (including the Meterset delivered when the beam position changes).
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The beam is moved and positioned at Scan Spot Position (6.0, 3.0).
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The beam is delivered until a Meterset Weight of 4 is reached (including the Meterset delivered when the beam position changes).
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The beam is moved and positioned at Scan Spot Position (2.0, 3.0).
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The beam is delivered until a Meterset Weight of 6 is reached (including the Meterset delivered when the beam position changes).
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The beam is switched off and positioned at Scan Spot Position (7.0, 5.0).
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The beam is delivered with a Meterset Weight of 4.
If Modulated Scan Mode Type (300A,0309) is LINEAR:
|
Position (X,Y) |
(1.0, 2.0) |
(6.0, 2.0) |
(6.0, 3.0) |
(2.0, 3.0) |
(7.0, 5.0) |
(7.0, 5.0) |
|---|---|---|---|---|---|---|
|
Meterset Weights |
0 |
6 |
4 |
6 |
0 |
4 |
Delivery Description:
-
The beam is positioned at Scan Spot Position (1,.0 2.0).
-
The beam is continuously delivered with a Meterset Weight of 6, while being moved from Scan Spot Position (1.0, 2.0) to Scan Spot Position (6.0, 2.0).
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The beam is continuously delivered with a Meterset Weight of 4, while being moved from Scan Spot Position (6.0, 2.0) to Scan Spot Position (6.0, 3.0).
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The beam is continuously delivered with a Meterset Weight of 6, while being moved from Scan Spot Position (6.0, 3.0) to Scan Spot Position (2.0, 3.0).
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The beam is switched off and positioned at Scan Spot Position (7.0, 5.0).
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The beam is delivered without moving from Scan Spot Position (7.0, 5.0) with Meterset Weight of 4.
C.8.8.25.9 Depth Dose Parameters Sequence
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:
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Nominal Range Modulated Region Depths (300A,0504) = 147\298
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Reference Dose Definition (300A,0512) = CENTER
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Distal Depth (300A,0502) = 301
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Distal Depth Fraction (300A,0501) = 0.9
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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
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The maximum dose for the highest energy of the non-range modulated component is used for determining the fractions.
- MAXIMUM
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The maximum dose of the range modulated depth dose distribution is used for determining the fractions.
- CENTER
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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:
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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
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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.
C.8.8.25.10 Isocenter to Accessory Distance
Snout Position (300A,030D) is defined at the Control Point level and can therefore vary during the beam, causing all the accessories attached to the Snout (Applicator, Block, Compensator, etc.) to move as well.
For each accessory which is attached to the Snout and has its distance to isocenter defined at the Beam level (such as Isocenter to Beam Limiting Device Distance (300A,00BB), Isocenter to Compensator Tray Distance (300A,02E4), Isocenter to Block Tray Distance (300A,00F7) ), the prescribed physical position of the accessory is defined at the first Control Point.
This is consistent with the approach used for Beam Limiting Device Boundaries and Positions (see Section C.8.8.25.3 Leaf Position Boundaries).
For accessories which are attached to the Snout whose distance is defined at the Control Point level, such as Isocenter to Lateral Spreading Device Distance (300A,0374) and Isocenter to Range Modulator Distance (300A,038A), and are attached to the Snout, both the Snout Position (300A,030D) and the accessory distance must change by the same amount.
C.8.8.25.11 Block and Compensator Data
Similarly to Section C.8.8.25.3, in the case where Snout Position (300A,030D) changes between control points, the scaling factor to be used to convert from DICOM data defined at the isocenter plane (such as Block Data (300A,0106) and Isocenter to Compensator Distances (300A,02E6) ) to the physical dimension of the accessories is purely based on the Isocenter to Compensator Tray Distance (300A,02E4) and Isocenter to Compensator Distances (300A,02E6) defined at the beam level and should not take into account the possible effect of Snout Position (300A,030D) changes between Control Points.
C.8.8.25.12 Enhanced RT Beam Limiting Device Sequence and Enhanced RT Beam Limiting Opening Sequence
When the value of Enhanced RT Beam Limiting Device Definition Flag (3008,00A3) has the value YES, the following applies to the content of Enhanced RT Beam Limiting Device Sequence (3008,00A1) and Enhanced RT Beam Limiting Opening Sequence (3008,00A2):
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For the Beam Modifier Definition Coordinate System used the following applies:
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The Base Beam Modifier Definition Coordinate System is the [IEC 61217] GANTRY coordinate system.
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The RT Device Distance Reference Location is (130359, DCM, "Treatment Machine Isocenter")
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The value of the RT Beam Modifier Definition Distance (300A,0688) equals 0 since the plane of the RT Beam Modifier Definition is at the Isocenter.
-
The value of the Beam Modifier Orientation Angle (300A,0645) is 0 for IEC X direction and 90 for IEC Y direction.
Note
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The values of boundaries and openings are therefore the same as if comparable parameters would be expressed in the Ion Beam Limiting Device Sequence (300A,03A4).
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The values of the boundaries in the Ion Beam Limiting Device Sequence (300A,03A4) correspond to the Snout Position (300A,030D) of the first Control Point only.
-
-
-
Values of Attributes of the Module RT Tolerance Tables Section C.8.8.11 apply to the Enhanced RT Beam Limiting Device Openings as specified in Section C.8.8.14.17.