DICOM PS3.3 2019d - Information Object Definitions

C.8.8.25 RT Ion Beams Module

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

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

Attribute Name

Tag

Type

Description

Ion Beam Sequence

(300A,03A2)

1

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

One or more Items shall be included in this Sequence.

>Beam Number

(300A,00C0)

1

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

>Beam Name

(300A,00C2)

1

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

>Beam Description

(300A,00C3)

3

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

>Beam Type

(300A,00C4)

1

Motion characteristic of Beam.

Enumerated Values:

STATIC

all beam parameters remain unchanged during delivery

DYNAMIC

one or more beam parameters changes during delivery

>Radiation Type

(300A,00C6)

1

Particle type of Beam.

Defined Terms:

PHOTON

PROTON

ION

>Radiation Mass Number

(300A,0302)

1C

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

>Radiation Atomic Number

(300A,0304)

1C

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

>Radiation Charge State

(300A,0306)

1C

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

>Scan Mode

(300A,0308)

1

The method of beam scanning to be used during treatment.

Defined Terms:

NONE

No beam scanning is performed.

UNIFORM

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

MODULATED

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

MODULATED_SPEC

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

>Modulated Scan Mode Type

(300A,0309)

1C

Defines the specialization of a modulated scan mode.

Defined Terms:

STATIONARY

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

LEAPING

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

LINEAR

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

MIXED

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

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

See Section C.8.8.25.8.

>Treatment Machine Name

(300A,00B2)

2

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

>Manufacturer

(0008,0070)

3

Manufacturer of the equipment to be used for beam delivery.

>Institution Name

(0008,0080)

3

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

>Institution Address

(0008,0081)

3

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

>Institutional Department Name

(0008,1040)

3

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

>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.

>>Include Table 8.8-1 “Code Sequence Macro Attributes”

BCID 7030 “Institutional Departments, Units and Services”.

>Manufacturer's Model Name

(0008,1090)

3

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

>Device Serial Number

(0018,1000)

3

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

>Primary Dosimeter Unit

(300A,00B3)

1

Measurement unit of machine dosimeter.

Enumerated Values:

MU

Monitor Unit

NP

number of particles

>Referenced Tolerance Table Number

(300C,00A0)

3

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

>Virtual Source-Axis Distances

(300A,030A)

1

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

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

>Depth Dose Parameters Sequence

(300A,0505)

3

Set of parameters describing the depth dose distribution.

Only a single Item is permitted in this Sequence.

>>Reference Dose Definition

(300A,0512)

1

Definition of the 100% reference dose level.

Defined Terms:

HIGHEST

MAXIMUM

CENTER

See Section C.8.8.25.9.

>>Distal Depth

(300A,0502)

1

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

See Section C.8.8.25.9.

>>Distal Depth Fraction

(300A,0501)

1

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

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

See Section C.8.8.25.9.

>>Nominal Range Modulated Region Depths

(300A,0504)

1C

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

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

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

See Section C.8.8.25.9.

>>Nominal Range Modulation Fractions

(300A,0503)

1C

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

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

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

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

See Section C.8.8.25.9.

>Ion Beam Limiting Device Sequence

(300A,03A4)

3

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

One or more Items are permitted in this Sequence.

>>RT Beam Limiting Device Type

(300A,00B8)

1

Type of beam limiting device (collimator).

Enumerated Values:

X

symmetric jaw pair in IEC X direction

Y

symmetric jaw pair in IEC Y direction

ASYMX

asymmetric jaw pair in IEC X direction

ASYMY

asymmetric pair in IEC Y direction

MLCX

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

MLCY

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

>>Isocenter to Beam Limiting Device Distance

(300A,00BB)

2

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

See Section C.8.8.25.4.

>>Number of Leaf/Jaw Pairs

(300A,00BC)

1

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

>>Leaf Position Boundaries

(300A,00BE)

1C

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

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

>Referenced Patient Setup Number

(300C,006A)

3

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

>Referenced Reference Image Sequence

(300C,0042)

3

Reference images used for validation of current beam.

One or more Items are permitted in this Sequence.

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

>>Reference Image Number

(300A,00C8)

1

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

>Treatment Delivery Type

(300A,00CE)

1

Delivery Type of treatment.

Defined Terms:

TREATMENT

Normal patient treatment

OPEN_PORTFILM

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

TRMT_PORTFILM

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

CONTINUATION

Continuation of interrupted treatment

SETUP

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

>Referenced Dose Sequence

(300C,0080)

3

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

One or more Items are permitted in this Sequence.

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

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

>Number of Wedges

(300A,00D0)

1

Number of wedges associated with current beam.

>Total Wedge Tray Water-Equivalent Thickness

(300A,00D7)

3

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

>Ion Wedge Sequence

(300A,03AA)

1C

Sequence of treatment wedges.

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

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

>>Wedge Number

(300A,00D2)

1

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

>>Wedge Type

(300A,00D3)

2

Type of wedge (if any) defined for Beam.

Defined Terms:

STANDARD

standard (static) wedge

MOTORIZED

single wedge that can be removed from beam remotely.

PARTIAL_STANDARD

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

PARTIAL_MOTORIZ

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

>>Wedge ID

(300A,00D4)

3

User-supplied identifier for Wedge.

>>Accessory Code

(300A,00F9)

3

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

>>Wedge Angle

(300A,00D5)

2

Nominal wedge angle (degrees).

>>Wedge Orientation

(300A,00D8)

2

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

>>Isocenter to Wedge Tray Distance

(300A,00D9)

1

Isocenter to downstream edge of wedge tray (mm).

See Section C.8.8.25.4

>Number of Compensators

(300A,00E0)

1

Number of compensators associated with current Beam.

>Total Compensator Tray Water-Equivalent Thickness

(300A,02E3)

3

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

>Ion Range Compensator Sequence

(300A,02EA)

1C

Sequence of compensators.

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

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

>>Compensator Description

(300A,02EB)

3

User defined description for the compensator.

>>Compensator Number

(300A,00E4)

1

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

>>Material ID

(300A,00E1)

2

User-supplied identifier for material used to manufacture Compensator.

>>Compensator ID

(300A,00E5)

3

User-supplied identifier for the compensator.

>>Accessory Code

(300A,00F9)

3

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

>>Isocenter to Compensator Tray Distance

(300A,02E4)

1C

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

>>Compensator Divergence

(300A,02E0)

1

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

Enumerated Values:

PRESENT

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

ABSENT

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

>>Compensator Mounting Position

(300A,02E1)

1

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

Enumerated Values:

PATIENT_SIDE

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

SOURCE_SIDE

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

DOUBLE_SIDED

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

>>Compensator Rows

(300A,00E7)

1

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

>>Compensator Columns

(300A,00E8)

1

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

>>Compensator Pixel Spacing

(300A,00E9)

1

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

>>Compensator Position

(300A,00EA)

1

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

>>Compensator Column Offset

(300A,02E5)

1C

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

>>Compensator Thickness Data

(300A,00EC)

1

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

>>Isocenter to Compensator Distances

(300A,02E6)

1C

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

>>Compensator Relative Stopping Power Ratio

(300A,02E7)

3

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

>>Compensator Milling Tool Diameter

(300A,02E8)

3

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

>Number of Boli

(300A,00ED)

1

Number of boli associated with current Beam.

>Referenced Bolus Sequence

(300C,00B0)

1C

Sequence of boli associated with Beam.

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

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

>>Referenced ROI Number

(3006,0084)

1

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

>>Accessory Code

(300A,00F9)

3

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

>Number of Blocks

(300A,00F0)

1

Number of shielding blocks associated with Beam.

>Total Block Tray Water-Equivalent Thickness

(300A,00F3)

3

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

>Ion Block Sequence

(300A,03A6)

1C

Sequence of blocks associated with Beam.

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

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

>>Block Tray ID

(300A,00F5)

3

User-supplied identifier for block tray.

>>Accessory Code

(300A,00F9)

3

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

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

>>Isocenter to Block Tray Distance

(300A,00F7)

1

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

>>Block Type

(300A,00F8)

1

Type of block. See Section C.8.8.14.4.

Enumerated Values:

SHIELDING

blocking material is inside contour

APERTURE

blocking material is outside contour

>>Block Divergence

(300A,00FA)

1

Indicates presence or otherwise of geometrical divergence.

Enumerated Values:

PRESENT

block edges are shaped for beam divergence

ABSENT

block edges are not shaped for beam divergence

>>Block Mounting Position

(300A,00FB)

1

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

Enumerated Values:

PATIENT_SIDE

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

SOURCE_SIDE

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

>>Block Number

(300A,00FC)

1

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

>>Block Name

(300A,00FE)

3

User-defined name for block.

>>Material ID

(300A,00E1)

2

User-supplied identifier for material used to manufacture Block.

>>Block Thickness

(300A,0100)

1

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

>>Block Number of Points

(300A,0104)

1

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

>>Block Data

(300A,0106)

1

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

>>Number of Block Slab Items

(300A,0440)

3

Number of Block Slabs comprising the Block.

Value shall be greater than 1.

>>Block Slab Sequence

(300A,0441)

1C

Sequence of slab(s) that comprise the block.

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

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

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

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

>>>Block Slab Number

(300A,0443)

1

Identification number of the Block Slab.

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

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

>>>Block Slab Thickness

(300A,0442)

3

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

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

>>>Accessory Code

(300A,00F9)

3

Machine-readable identifier for this accessory.

>Snout Sequence

(300A,030C)

3

Sequence of Snouts associated with Beam.

Only a single Item is permitted in this Sequence.

>>Snout ID

(300A,030F)

1

User or machine supplied identifier for Snout.

>>Accessory Code

(300A,00F9)

3

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

>Applicator Sequence

(300A,0107)

3

Sequence of Applicators associated with Beam.

Only a single Item is permitted in this Sequence.

>>Applicator ID

(300A,0108)

1

User or machine supplied identifier for Applicator.

>>Accessory Code

(300A,00F9)

3

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

>>Applicator Type

(300A,0109)

1

Type of applicator.

Defined Terms:

ION_SQUARE

square ion applicator

ION_RECT

rectangular ion applicator

ION_CIRC

circular ion applicator

ION_SHORT

short ion applicator

ION_OPEN

open (dummy) ion applicator

INTRAOPERATIVE

intraoperative (custom) applicator

STEREOTACTIC

stereotactic applicator

>>Applicator Description

(300A,010A)

3

User-defined description for Applicator.

>General Accessory Sequence

(300A,0420)

3

A Sequence of General Accessories associated with this Beam.

One or more Items are permitted in this Sequence.

>>General Accessory Number

(300A,0424)

1

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

>>General Accessory ID

(300A,0421)

1

User or machine supplied identifier for General Accessory.

>>General Accessory Description

(300A,0422)

3

User supplied description of General Accessory.

>>General Accessory Type

(300A,0423)

3

Specifies the type of accessory.

Defined Terms:

GRATICULE

Accessory tray with a radio-opaque grid

IMAGE_DETECTOR

Image acquisition device positioned in the beam line

RETICLE

Accessory tray with radio-transparent markers or grid

>>Accessory Code

(300A,00F9)

3

Machine-readable identifier for this accessory

>>Source to General Accessory Distance

(300A,0425)

3

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

>Number of Range Shifters

(300A,0312)

1

Number of range shifters associated with current beam.

>Range Shifter Sequence

(300A,0314)

1C

Sequence of range shifters associated with Beam.

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

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

>>Range Shifter Number

(300A,0316)

1

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

>>Range Shifter ID

(300A,0318)

1

User or machine supplied identifier for Range Shifter.

>>Accessory Code

(300A,00F9)

3

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

>>Range Shifter Type

(300A,0320)

1

Type of Range Shifter.

Defined Terms:

ANALOG

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

BINARY

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

>>Range Shifter Description

(300A,0322)

3

User defined description of Range Shifter.

>Number of Lateral Spreading Devices

(300A,0330)

1

Number of lateral spreading devices associated with current beam.

>Lateral Spreading Device Sequence

(300A,0332)

1C

Sequence of lateral spreading devices associated with Beam.

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

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

>>Lateral Spreading Device Number

(300A,0334)

1

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

>>Lateral Spreading Device ID

(300A,0336)

1

User or machine supplied identifier for Lateral Spreading Device.

>>Accessory Code

(300A,00F9)

3

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

>>Lateral Spreading Device Type

(300A,0338)

1

Type of Lateral Spreading Device.

Defined Terms:

SCATTERER

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

MAGNET

nozzle configuration of magnet devices to expand beam laterally.

>>Lateral Spreading Device Description

(300A,033A)

3

User-defined description for lateral spreading device.

>Number of Range Modulators

(300A,0340)

1

Number of range modulators associated with current beam.

>Range Modulator Sequence

(300A,0342)

1C

Sequence of range modulators associated with Beam.

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

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

>>Range Modulator Number

(300A,0344)

1

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

>>Range Modulator ID

(300A,0346)

1

User or machine supplied identifier for Range Modulator.

>>Accessory Code

(300A,00F9)

3

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

>>Range Modulator Type

(300A,0348)

1

Type of Range Modulator.

Defined Terms:

FIXED

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

WHL_FIXEDWEIGHTS

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

WHL_MODWEIGHTS

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

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

>>Range Modulator Description

(300A,034A)

3

User-defined description of Range Modulator.

>>Beam Current Modulation ID

(300A,034C)

1C

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

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

>Fixation Light Azimuthal Angle

(300A,0356)

3

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

>Fixation Light Polar Angle

(300A,0358)

3

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

>Fixation Eye

(300A,0150)

3

The eye used for fixation.

Enumerated Values:

L

left eye

R

right eye

>Final Cumulative Meterset Weight

(300A,010E)

1C

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

>Number of Control Points

(300A,0110)

1

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

>Ion Control Point Sequence

(300A,03A8)

1

Sequence of machine configurations describing Ion treatment beam.

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

See Section C.8.8.25.7.

>>Control Point Index

(300A,0112)

1

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

>>Cumulative Meterset Weight

(300A,0134)

2

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

>>Referenced Dose Reference Sequence

(300C,0050)

3

A Sequence of Dose References for current Beam.

One or more Items are permitted in this Sequence.

>>>Referenced Dose Reference Number

(300C,0051)

1

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

>>>Cumulative Dose Reference Coefficient

(300A,010C)

2

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

>>Nominal Beam Energy

(300A,0114)

1C

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

>>KVP

(0018,0060)

1C

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

>>Meterset Rate

(300A,035A)

3

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

>>Ion Wedge Position Sequence

(300A,03AC)

1C

Sequence of Wedge positions for current control point.

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

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

>>>Referenced Wedge Number

(300C,00C0)

1

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

>>>Wedge Position

(300A,0118)

1

Position of Wedge at current Control Point.

Enumerated Values:

IN

OUT

>>>Wedge Thin Edge Position

(300A,00DB)

1C

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

>>Range Shifter Settings Sequence

(300A,0360)

1C

Sequence of Range Shifter settings for the current control point.

One or more Items shall be included in this Sequence.

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

>>>Referenced Range Shifter Number

(300C,0100)

1

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

>>>Range Shifter Setting

(300A,0362)

1

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

>>>Isocenter to Range Shifter Distance

(300A,0364)

3

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

>>>Range Shifter Water Equivalent Thickness

(300A,0366)

3

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

>>Lateral Spreading Device Settings Sequence

(300A,0370)

1C

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

One or more Items shall be included in this Sequence.

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

>>>Referenced Lateral Spreading Device Number

(300C,0102)

1

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

>>>Lateral Spreading Device Setting

(300A,0372)

1

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

>>>Isocenter to Lateral Spreading Device Distance

(300A,0374)

3

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

>>>Lateral Spreading Device Water Equivalent Thickness

(300A,033C)

3

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

>>Range Modulator Settings Sequence

(300A,0380)

1C

Sequence of Range Modulator Settings for current control point.

One or more Items shall be included in this Sequence.

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

>>>Referenced Range Modulator Number

(300C,0104)

1

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

>>>Range Modulator Gating Start Value

(300A,0382)

1C

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

>>>Range Modulator Gating Stop Value

(300A,0384)

1C

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

>>>Range Modulator Gating Start Water Equivalent Thickness

(300A,0386)

3

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

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

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

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

>>>Range Modulator Gating Stop Water Equivalent Thickness

(300A,0388)

3

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

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

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

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

>>>Isocenter to Range Modulator Distance

(300A,038A)

3

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

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

>>Gantry Angle

(300A,011E)

1C

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

>>Gantry Rotation Direction

(300A,011F)

1C

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

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Gantry Pitch Angle

(300A,014A)

2C

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

>>Gantry Pitch Rotation Direction

(300A,014C)

2C

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

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Beam Limiting Device Angle

(300A,0120)

1C

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

>>Beam Limiting Device Rotation Direction

(300A,0121)

1C

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

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Scan Spot Tune ID

(300A,0390)

1C

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

>>Scan Spot Reordering Allowed

(300A,0395)

3

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

Enumerated Values:

ALLOWED

The delivery device may deliver the spots in any order

NOT ALLOWED

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

>>Number of Scan Spot Positions

(300A,0392)

1C

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

>>Scan Spot Position Map

(300A,0394)

1C

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

>>Scan Spot Meterset Weights

(300A,0396)

1C

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

>>Scanning Spot Size

(300A,0398)

3

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

>>Number of Paintings

(300A,039A)

1C

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

>>Patient Support Angle

(300A,0122)

1C

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

>>Patient Support Rotation Direction

(300A,0123)

1C

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

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Pitch Angle

(300A,0140)

2C

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

>>Table Top Pitch Rotation Direction

(300A,0142)

2C

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

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation

>>Table Top Roll Angle

(300A,0144)

2C

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

>>Table Top Roll Rotation Direction

(300A,0146)

2C

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

Enumerated Values:

CW

clockwise

CC

counter-clockwise

NONE

no rotation.

>>Head Fixation Angle

(300A,0148)

3

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

>>Chair Head Frame Position

(300A,0151)

3

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

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

Note

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

Typically used for eye treatments.

>>Table Top Vertical Position

(300A,0128)

2C

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

>>Table Top Longitudinal Position

(300A,0129)

2C

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

>>Table Top Lateral Position

(300A,012A)

2C

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

>>Snout Position

(300A,030D)

2C

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

>>Isocenter Position

(300A,012C)

2C

Isocenter coordinates (x,y,z) in the Patient-Based Coordinate System described in Section C.7.6.2.1.1 (mm). Required for first Item of Segment Control Point Sequence, or if Segment Isocenter Position changes during Beam.

>>Surface Entry Point

(300A,012E)

3

Patient surface entry point coordinates (x,y,z), along the central axis of the beam, in the Patient-Based Coordinate System described in Section C.7.6.2.1.1 (mm).

>>External Contour Entry Point

(300A,0133)

3

External Contour entry point coordinates (x,y,z) in the Patient-Based Coordinate System described in Section C.7.6.2.1.1 (mm).

See Section C.8.8.14.15.


C.8.8.25.1 Beam Identifying Information

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

DICOM PS3.3 2019d - Information Object Definitions