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.8.8.25-1RT ION BEAMS MODULE ATTRIBUTES

Attribute Name Tag Type Description
Ion Beam Sequence (300A,03A2) 1 Introduces 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 = The beam is scanned between control points to create a uniform lateral fluence distribution across the field. MODULATED = The beam is scanned between control points to create a modulated lateral fluence distribution across the field.
>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.
>Ion Beam Limiting Device Sequence (300A,03A4) 3 Introduces 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. 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 SOP Instance Reference Macro Table 10-11
>>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 SOP Instance Reference Macro Table 10-11 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 Introduces 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 Typer 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 Introduces 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 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 the Compensator Position (300A,00EA) for even numbered rows. Required if the compensator pattern is hexogonal.
>>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 sent 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 sent 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 sections C.8.8.14.9 and 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 physcial 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 Introduces 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 Introduces 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.
>>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).
>Snout Sequence (300A,030C) 3 Introduces 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 Introduces 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 = rectangluar ion applicator ION_CIRC = circular ion applicator ION_SHORT = short ion applicator ION_OPEN = open (dummy) ion applicator INTEROPERATIVE = interoperative (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
>Number of Range Shifters (300A,0312) 1 Number of range shifters associated with current beam.
>Range Shifter Sequence (300A,0314) 1C Introduces 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 Introduces 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 Introduces 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 Patient Support Identification Macro Table C.8.8.28-1
>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.
>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 Introduces 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 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 Introduces 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 Introduces 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 Shiffter 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 Introduces 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 Introduces 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 Beam Limiting Device Position Macro Table C.8.8.27-1
>>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 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 C.8.8.14.8 and 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.
>>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.
>>Scan Spot Position Map (300A,0394) 1C The x and y coordinates of the scan spots are defined as projected onto the machine isocentric plane in the IEC GANTRY coordinate system (mm). Required if Scan Mode (300A,0308) is MODULATED. Contains 2N values where N is the Number of Scan Spot Positions (300A,0392).
>>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.
>>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.
>>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 C.8.8.14.8 and 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 C.8.8.14.8 and 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.
>>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 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 C.7.6.2.1.1 (mm).

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 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 M x and M y as the magnification factors for the scaling of the leaf positions from their real space position to the isocenter plane. M x and M y are calculated from the virtual SADs VSAD x or VSAD y , respectively, and the Isocenter to Beam Limiting Device Distance (300A,00BB).

[pic]

The magnification factor M α for an arbitrary beam limiting device angle ( then becomes:

[pic]

The 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 sent, even though they are only virtual trays.

Figure C.8.8.25-1 shows an example.

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Figure C.8.8.25-1 Virtual Source-Axis Distances

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

a.) 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.

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

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Figure C.8.8.25-2 Fixed Beam Line

C.8.8.25.6.2 Table Top Pitch and Table Top Roll

Pitch and Roll Coordinate Systems of the Table Top are not defined in IEC 61217. These angles are defined in the DICOM standard in a way compatible with the current notion of IEC by introducing them 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 (t; see Figure C.8.8.25-3. An increase in the value of angle (t 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 (t; see Figure C.8.8.25-4. An increase in the value of angle (t corresponds to the clockwise rotation of the Table Top as viewed from the Table Top coordinate system origin along the positive Yt axis.

[pic]

Figure C.8.8.25-3 Table Top Pitch Angle

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Figure C.8.8.25-4 Table Top Roll Angle

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.

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

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Figure C.8.8.25-5 Patient’s eye view

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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 (g; see Figure C.8.8.25-7. An increase in the value of angle (g corresponds to the clockwise rotation as viewed from the isocenter along the positive Xg axis

[pic]

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 Control Point Sequence). Specifically, the following rules apply:

This definition allows unambigous and explicit determination of those parameters changing while irradation is occuring, 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 = 0Nominal Energy: 200Scan Spot Position Map: -40, -35, -40, -30 (Positions for 1 st 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 = 30.0Nominal Energy: 200Scan Spot Position Map: -40, -35, -40, -30 (Positions for 1 st segment)Scan Spot Meterset Weight: 0.0, 0.0, 0.0, … (All values are 0.0, because Meterset Weight difference betweeen Control Point 1 and 2 is 0.0)

Control Point 2: All applicable treatment parameters defined, Cumulative Meterset Weight = 30.0Nominal Energy: 180Scan Spot Position Map: -55, -40, -55, -35, (Positions for 2 nd 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 = 70.0Nominal Energy: 180Scan Spot Position Map: -55, -40, -55, -35, (Positions for 2 nd 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).