DICOM PS3.3 2020a - Information Object Definitions

C.36.2 RT Second Generation Macros (Current)
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### C.36.2 RT Second Generation Macros

#### C.36.2.1 RT Second Generation General Purpose Macros

##### C.36.2.1.1 Radiation Fraction Pattern Macro

The Radiation Fraction Pattern Macro specifies the intended fraction pattern to be used to deliver the radiation treatment.

Table C.36.2.1.1-1. Radiation Fraction Pattern Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Fraction Pattern Sequence | (3010,0079) | 1C | The pattern of delivery of fractions within and across days of the week in a machine-readable form. Required if a fraction pattern has been defined. Only a single Item shall be included in this Sequence.
>Number of Fraction Pattern Digits Per Day | (300A,0079) | 1C | The maximum number of fractions encodable within a day in a Fraction Pattern (3010,0087). Required if Weekday Fraction Pattern Sequence (3010,0087) is present. See Section C.36.2.1.1.1.1.
>Repeat Fraction Cycle Length | (300A,007A) | 1C | Number of weeks needed to describe fraction pattern. Required if Weekday Fraction Pattern Sequence (3010,0087) is present. See Section C.36.2.1.1.1.1.
>Weekday Fraction Pattern Sequence | (3010,0087) | 3 | Sequence of week-day based fraction patterns. Each Item represents an alternative pattern. One or more Items are permitted in this Sequence. See Section C.36.2.1.1.1.1.
>>Fraction Pattern | (300A,007B) | 3 | String of 0's (no treatment) and 1's (treatment) describing the fraction pattern for the fractions defined by this set. Length of string is 7 x Number of Fraction Pattern Digits Per Day x Repeat Fraction Cycle Length. The first character of the string represents Monday. See Section C.36.2.1.1.1.1.
>>Intended Start Day of Week | (3010,0086) | 3 | String of 0's (no treatment) and 1's (treatment) describing the intended start fraction for this set. Length of string is 7 x Number of Fraction Pattern Digits Per Day x Repeat Fraction Cycle Length. The first character of the string represents Monday. See Section C.36.2.1.1.1.2.
>Minimum Hours between Fractions | (3010,0084) | 3 | Minimum number of hours between consecutive fractions. Consecutive fractions are given in Number of Fraction Pattern Digits Per Day (300A,0079).
>Intended Fraction Start Time | (3010,0085) | 3 | The intended time(s) of day when the first RT Treatment Fraction of the day should be started.

###### C.36.2.1.1.1 Radiation Fraction Pattern Macro Attribute Descriptions

###### C.36.2.1.1.1.1 Fraction Pattern

The Radiation Fraction Pattern describes the intended scheme, i.e., how fractions are to be distributed along calendar days for the actual radiation set.

Examples of Fraction Patterns:

1. 1 fraction per day (Monday to Friday) , no fractions on Saturday and Sunday, 1 week-pattern:

   Number of Fraction Pattern Digits Per Day (300A,0079) = 1

   Repeat Fraction Cycle Length (300A,007A) = 1

   Fraction Pattern (300A,007B) = 1111100

2. 2 fractions per day (Monday to Friday) , no fractions on Saturday and Sunday 1 week-pattern:

   Number of Fraction Pattern Digits Per Day (300A,0079) = 2

   Repeat Fraction Cycle Length (300A,007A) = 1

   Fraction Pattern (300A,007B) = 11111111110000

3. 1 fraction per day (Monday, Wednesday, Friday) , no fractions on Saturday and Sunday 1 week-pattern:

   Number of Fraction Pattern Digits Per Day (300A,0079) = 1

   Repeat Fraction Cycle Length (300A,007A) = 1

   Fraction Pattern (300A,007B) = 1010100

4. 2 fractions per day (Monday, Wednesday, Friday) , one fraction on Saturday morning and Sunday afternoon 1 week-pattern:

   Number of Fraction Pattern Digits Per Day (300A,0079) = 2

   Repeat Fraction Cycle Length (300A,007A) = 1

   Fraction Pattern (300A,007B) = 11001100111001

5. 1 fraction per day every other day 2 week-pattern:

   Number of Fraction Pattern Digits Per Day (300A,0079) = 1

   Repeat Fraction Cycle Length (300A,007A) = 2

   Fraction Pattern (300A,007B) = 10101010101010

###### C.36.2.1.1.1.2 Intended Start Day of Week

The Intended Start Day of Week (3010,0086) specifies the day(s) of the week, when the first fraction of the treatment should be delivered. If more than one day is specified, one of the days may be selected to start the treatment.

The treatment then continues as specified in Fraction Pattern (300A,007B), irrespective of when the actual delivery starts.

Examples of Intended Start Day of Week and the relation to Fraction Pattern:

1. 1 Start Day, one fraction per day

   The treatment should start on Wednesday and be continued at Friday of the first week, followed by treatments at Monday, Wednesday, Friday the next week etc., until all fractions are delivered.

   Number of Fraction Pattern Digits Per Day (300A,0079) = 1

   Repeat Fraction Cycle Length (300A,007A) = 1

   Fraction Pattern (300A,007B) = 1010100

   Intended Start Day of Week (3010,0086) = 0010000

2. Start of any of 3 days, two fractions per day

   Treatment should start

   - on Monday morning and continued by 1 fraction on Monday afternoon, 2 fractions on Wednesday and Friday

   - or on Monday afternoon and continued by 2 fractions on Wednesday and Friday

   - or on Wednesday morning, followed by a fraction on Wednesday afternoon, folloed by 2 fractions on Friday.

   The treatment will continue the next week with 2 fractions on Monday, Wednesday, Friday etc. until all fractions are delivered.

   Number of Fraction Pattern Digits Per Day (300A,0079) = 1

   Repeat Fraction Cycle Length (300A,007A) = 2

   Fraction Pattern (300A,007B) = 11001100110000

   Intended Start Day of Week (3010,0086) = 11001000000000

##### C.36.2.1.2 RT Treatment Phase Macro

The treatment phase Macro contains the identification and additional information about an RT Treatment Phase.

Table C.36.2.1.2-1. RT Treatment Phase Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
RT Treatment Phase Index | (3010,003A) | 1 | Index of the RT Treatment Phase in the Sequence.
RT Treatment Phase UID | (3010,003B) | 2 | A UID by which this RT Treatment Phase can be referenced.
Include Table 10.31-1 “Entity Labeling Macro Attributes” |
Intended Phase Start Date | (3010,004C) | 2 | The date when this treatment phase is intended to start. See Section C.36.2.1.2.1.1.
Intended Phase End Date | (3010,004D) | 2 | The date when this treatment phase is intended to be completed. See Section C.36.2.1.2.1.1.

###### C.36.2.1.2.1 RT Treatment Phase Macro Attribute Descriptions

###### C.36.2.1.2.1.1 Intended Phase Start Date, Intended Phase End Date

The Intended Phase Start Date (3010,004C) and Intended Phase End Date (3010,004D) contains the date when this treatment phase is intended to be started or completed. Do not confuse the content of this Attribute with the date when the treatment delivery is scheduled or when it actually starts or ends. The scheduled date is managed by workflow systems where definitive treatment session scheduling is maintained. The actual date of performed delivery will be available in the RT Radiation Record Instances. The actual dates may differ from the Intended Phase Start Date (3010,004C) and/or Intended Phase End Date (3010,004D).

##### C.36.2.1.3 RT Treatment Phase Interval Macro

The RT Treatment Phase Interval Macro contains the information about time-relationship between RT Treatment Phases. This consists of sets of pair-wise relationships, declaring the relation of a earlier phase to a later, potentially overlapping, phase.

Table C.36.2.1.3-1. RT Treatment Phase Interval Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
RT Treatment Phase Interval Sequence | (3010,004E) | 2 | Intervals between treatment phases. Zero or more Items shall be included in this Sequence. See Section C.36.2.1.3.2.
>Basis RT Treatment Phase Index | (3010,003E) | 1 | The RT Treatment Phase which provides the basis for this interval. This index corresponds to an Item in the Intended RT Treatment Phase Sequence (3010,004B). See Section C.36.2.1.3.1.
>Related RT Treatment Phase Index | (3010,003F) | 1 | The RT Treatment Phase which is related to the phase identified by Basis RT Treatment Phase Index (3010,003E). Each RT Treatment Phase Index value shall appear in this Attribute in only one Item within this Sequence. This index corresponds to an Item in the Intended RT Treatment Phase Sequence (3010,004B). See Section C.36.2.1.3.1.
>Temporal Relationship Interval Anchor | (3010,004F) | 1C | The anchor point of the interval specified in this Item with respect to the phase referenced by the Basis RT Treatment Phase Index (3010,003E). Enumerated Values: START The interval is specified with respect to the start of the basis phase. END The interval is specified with respect to the end of the basis phase. Required if a value is present in Minimum Number of Interval Days (3010,0050) or Maximum Number of Interval Days (3010,0051).
>Minimum Number of Interval Days | (3010,0050) | 2 | The minimum number of days that the start of the related phase should follow the basis phase referenced in Basis RT Treatment Phase Index (3010,003E). Fractional values are allowed. Negative values are allowed if Temporal Relationship Interval Anchor (3010,004F) has a value of END.
>Maximum Number of Interval Days | (3010,0051) | 2 | The maximum number of days that the start of the related phase should follow the basis phase referenced Basis RT Treatment Phase Index (3010,003E). Fractional values are allowed. Negative values are allowed if Temporal Relationship Interval Anchor (3010,004F) has a value of END.

###### C.36.2.1.3.1 Referenced RT Treatment Phases

The RT Treatment Phase Interval Sequence (3010,004E) allows the definition of an interval between two treatment phases. RT Treatment Phases referenced by the Basis RT Treatment Phase Index (3010,003E) and the Related RT Treatment Phase Index (3010,003F) are related in terms of the number of days between them. Note that the number of days can also be negative and therefore the related treatment phase could start before the prior treatment phase starts respectively ends.

Each RT Treatment Phase identified by the Related RT Treatment Phase Index (3010,003F) may be related to only one RT Treatment Phase identified by the Basis RT Treatment Phase Index (3010,003E). Therefore, any Basis RT Treatment Phase Index (3010,003E) must only appear once in Related RT Treatment Phase Index (3010,003F) within the Sequence.

See also Section C.36.6.1.4.

As a result of the combinations possible, the maximum number of Items in the RT Treatment Phase Interval Sequence (3010,004E) shall be one less than the number of treatment phases present.

###### C.36.2.1.3.2 RT Treatment Phase Interval Conflicts

The Standard does not preclude encoding conflicting information.

##### C.36.2.1.4 Dosimetric Objective Macro

The Dosimetric Objective Macro specifies an intended goal to be used in the definition of the dosimetric plan, for plan optimization etc. Dosimetric Objectives may define limits which affect the dose, such as dose volume constraints, minimum or maximum dose, treatment time or MU limits, and radiobiologic effects.

Dosimetric Objectives, such as dose volume constraints, minimum or maximum dose, etc., can be used to specify dose goals for anatomical or other treatment volumes that are referenced by Conceptual Volumes. Other Dosimetric Objectives can also be used to specify general plan optimization objectives not related to anatomical or other treatment volumes, such as Meterset Minimization, etc.

Table C.36.2.1.4-1. Dosimetric Objective Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Dosimetric Objective UID | (3010,006E) | 1 | A UID by which this Dosimetric Objective can be referenced. See Section C.36.2.1.4.1.1.
Originating SOP Instance Reference Sequence | (3010,0007) | 1C | Reference to the SOP Instance that contains the original definition of this Dosimetric Objective identified by Dosimetric Objective UID (3010,006E). Required when the Dosimetric Objective UID (3010,0948) was not issued in the current SOP Instance, but read from another SOP instance.. Only a single Item shall be included in this Sequence.
>Include Table 10-11 “SOP Instance Reference Macro Attributes” |
Dosimetric Objective Type Code Sequence | (3010,006D) | 1 | The type of dose objective which this Item represents. Only a single Item shall be included in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | DCID 9500 “Dosimetric Objective Types”.
Dosimetric Objective Parameter Sequence | (3010,0070) | 2 | Parameters for the objective identified in Dosimetric Objective Type Code Sequence (3010,006D). Zero or more Items shall be included in this Sequence. See Section C.36.2.1.4.1.2.
>Include Table 10-2 “Content Item Macro Attributes Description” |
>Radiobiological Dose Effect Sequence | (3010,0001) | 1C | Describes the radiobiological effects if any that are taken into account to compute dose. Required if Dosimetric Objective Parameter Sequence (3010,0070) contains a parameter which represents a dose. Only a single Item shall be included in this Sequence. See Section C.36.2.1.4.1.2.
>>Include Table C.36.2.1.5-1 “Radiobiological Dose Effect Description Macro Attributes” |
Absolute Dosimetric Objective Flag | (3010,0073) | 1 | Whether the objective must be met by the resulting Radiotherapy treatment plan. Enumerated Values: YES Objective must be met. NO Objective should be met but may be compromised. Detecting whether or not a Radiotherapy treatment plan has met this Dosimetric Objective and how this situation is handled is out of scope of the Standard.
Dosimetric Objective Purpose | (3010,0075) | 2 | The purpose for which the objective is to be used. Enumerated Values: OPTIMIZATION Used as an input to the optimization process. EVALUATION Used as a tool for evaluation. BOTH Used as both an input to the optimization process and for evaluation.

###### C.36.2.1.4.1 Dosimetric Objective Macro Attribute Descriptions

###### C.36.2.1.4.1.1 Dosimetric Objective UID

Dosimetric Objectives (see Section C.36.6.1.6) are identified by UIDs. These UIDs serve as a key to allow references of Dosimetric Objectives within or across various SOP Instances.

###### C.36.2.1.4.1.2 Dosimetric Objective Parameter Sequence

A Dosimetric Objective is described by a type expressed in the Dosimetric Objective Type Code Sequence (3010,006D), and a Sequence of zero or more parameters to quantify the objective within the Dosimetric Objective Parameter Sequence (3010,0070).

Table C.36.2.1.4-2 specifies the parameters that shall be sent.

Table C.36.2.1.4-2. Dosimetric Objective Parameters

Dosimetric Objective Type Code Sequence (3010,006D) | Parameter | Parameter | Parameter
--- | --- | --- | ---
Concept Name Code(s) | Value Type(s) | Measurement Units Code(s)
Code included in: CID 9532 “No-Parameter Dosimetric Objectives” | none | none | none
Code included in: CID 9529 “Single Dose Dosimetric Objectives” | EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")
Code included in: CID 9530 “Percentage and Dose Dosimetric Objectives” | EV (130021, DCM, "Specified Volume Percentage") | NUMERIC | Units = EV (%,UCUM,"Percent")
EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")
Code included in: CID 9531 “Volume and Dose Dosimetric Objectives” | EV (130020, DCM, "Specified Volume Size") | NUMERIC | Units = EV (cm3,UCUM,"Cubic Centimeter")
EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")
(130010, DCM, "Minimum Conformity Index") | EV (130074, DCM, "Specified Conformity Index") | NUMERIC | Units = EV (1,UCUM,"no units")
EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")
(130011, DCM, "Minimum Healthy Tissue Conformity Index") | EV (130075, DCM, "Specified Healthy Tissue Conformity Index") | NUMERIC | Units = EV (1,UCUM,"no units")
EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")
(130012, DCM, "Minimum Conformation Number") | EV (130076, DCM, "Specified Conformation Number") | NUMERIC | Units = EV (1,UCUM,"no units")
EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")
(130013, DCM, "Maximum Homogeneity Index") | EV (130077, DCM, "Specified Homogeneity Index") | NUMERIC | Units = EV (1,UCUM,"no units")
EV (130019, DCM, "Specified Radiation Dose") | NUMERIC | Units = EV (Gy,UCUM,"Gray")

###### C.36.2.1.4.1.2.1 Dosimetric Objective Parameter Sequence Examples

To describe the objective that a maximum of 30% of the volume can receive 50 Gy or more (V50<=30%), one would use the Dosimetric Objective Type Code Sequence (3010,006D) with code value (130015, DCM, "Maximum Percent Volume at Dose"), with the parameters specified in the Dosimetric Objective Parameter Sequence (3010,0070) as follows:

Dosimetric Objective Sequence (3010,006C):

- Dosimetric Objective Type Code Sequence (3010,006D):

  - (130015, DCM, "Maximum Percent Volume at Dose")

- Dosimetric Objective Parameter Sequence (3010,0070)

  - Item 1:

    - Value Type (0040,A040) = NUMERIC

    - Concept Name Code Sequence (0040,A043)

      - (130021, DCM, "Specified Volume Percentage")

    - Numeric Value (0040,A30A) = 30

    - Measurement Units Code Sequence (0040,08EA)

      - (%, UCUM, "Percent")

  - Item 2:

    - Value Type (0040,A040) = NUMERIC

    - Concept Name Code Sequence (0040,A043)

      - (130019, DCM, "Specified Radiation Dose")

    - Numeric Value (0040,A30A) = 50

    - Measurement Units Code Sequence (0040,08EA)

      - (Gy, UCUM, "Gray")

###### C.36.2.1.4.1.3 Radiobiological Dose Effect Sequence

The Radiobiological Dose Effect Sequence (3010,0001) specifies whether a code value of (Gy,UCUM,"Gray") in the Measurement Units Code Sequence (0040,08EA) in the Dosimetric Objective Parameter Sequence (3010,0070) denotes physical or effective dose.

##### C.36.2.1.5 Radiobiological Dose Effect Description Macro

The Radiobiological Dose Effect Description Macro describes whether dose values are provided as physical dose or effective dose. An effective dose value incorporates adjustments to dose by taking into account the radiobiological effects.

Table C.36.2.1.5-1. Radiobiological Dose Effect Description Macro Attributes

Attribute Name | Tag | Type | Attribute Description
--- | --- | --- | ---
Radiobiological Dose Effect Flag | (3010,0002) | 1 | Whether radiobiological effects are taken into account for a given dose value. Enumerated Values: YES Effective dose after correction for biological effect. NO Physical dose.
Effective Dose Calculation Method Category Code Sequence | (3010,0003) | 2C | The category of the method used to calculate the effective dose. Required if Radiobiological Dose Effect Flag (3010,0002) equals YES. Zero or more Items shall be included in this Sequence.
>Include Table 8.8-1 “Code Sequence Macro Attributes” | DCID 9537 “Effective Dose Calculation Method Categories”.
>Effective Dose Calculation Method Code Sequence | (3010,0004) | 3 | Defines the effective dose calculation method. One or more Items are permitted in this Sequence.
>>Include Table 8.8-1 “Code Sequence Macro Attributes” | See Section C.36.2.1.5.1.1.
Effective Dose Calculation Method Description | (3010,0005) | 2C | The description of the method used to calculate the effective dose. Required if Radiobiological Dose Effect Flag (3010,0002) is YES.

###### C.36.2.1.5.1 Radiobiological Dose Effect Description Macro Attribute Descriptions

###### C.36.2.1.5.1.1 Effective Dose Method Modifier Code Sequence

The calculation of the radiobiological effect may be further described by a specific method.

In Table C.36.2.1.5-2, if the Effective Dose Calculation Method Category Code Sequence (3010,0003) has the code value specified in the left column, the Context Group for Effective Dose Calculation Method Code Sequence (3010,0004) shall be the one specified in the right column.

Table C.36.2.1.5-2. Effective Dose Calculation Method Context Groups

Effective Dose Calculation Method Category Code Sequence (3010,0003) | Context Group for Effective Dose Calculation Method Code Sequence (3010,0004)
--- | ---
(130126, DCM, "Radiation transport-based methods") | DCID 9538 “Radiation Transport-based Effective Dose Method Modifiers”
(130127, DCM, "Fractionation-based or temporally-based methods") | DCID 9539 “Fractionation-based Effective Dose Method Modifiers”

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DICOM PS3.3 2020a - Information Object Definitions