DICOM PS3.3 2024a - Information Object Definitions
C.8.8.14.7 Cumulative Dose Reference Coefficient

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

The sum of the doses of all beams calculated to the referenced dose reference may be used in different clinical scenarios, indicated by the Dose Value Purpose (300A,061D) attribute value, see Section C.8.8.10.1.

Example

In a single target case with two beams, a volume prescription of 20 Gy over 10 fractions, the single target may be represented by two Items in the Dose Reference Sequence (300A,0010): one for tracking of the dose values over the course of the delivery of a treatment plan, and one for QA purposes, where the dose value is recalculated and compared to the planned value. The first Item may therefore contain a nominal dose by a physician (e.g., 20Gy), the second Item a calculated dose at a given spatial location (e.g., 21.785Gy). The dose values are determined using the Beam Dose (300A,0084) with a Beam Dose Meaning (300A,008B) FRACTION_LEVEL (indicating that the beam dose was calculated on fraction level and carries a nominally distributed dose only).

Dose Reference Sequence

(300A,0010)

<Sequence>

>Item 1

>Dose Reference Number

(300A,0012)

1

>Dose Reference UID

(300A,0013)

1.2.3.4.1

>Dose Reference Structure Type

(300A,0014)

VOLUME

>Dose Value Purpose

(300A,061D)

TRACKING

>Dose Value Interpretation

(300A,068B)

NOMINAL

>Dose Reference Description

(300A,0016)

Tumor

>Referenced ROI Number

(3006,0084)

5

>Dose Reference Type

(300A,0020)

TARGET

>Item 2

>Dose Reference Number

(300A,0012)

2

>Dose Reference UID

(300A,0013)

1.2.3.4.2

>Dose Reference Structure Type

(300A,0014)

COORDINATES

>Dose Value Purpose

(300A,061D)

QA

>Dose Value Interpretation

(300A,068B)

ACTUAL

>Dose Reference Description

(300A,0016)

Tumor

>Dose Reference Point Coordinates

(300A,0018)

3.1\4.2\5.3

>Dose Reference Type

(300A,0020)

TARGET

Table C.8.8.14.7-1. Cumulative Dose Reference Calculation Example

Beam Dose (300A,0084) with Beam Dose Meaning (300A,008B): FRACTION_LEVEL

Dose Reference Number (300A,0012): 1

Dose Reference Number (300A,0012): 2

Final value of Cumulative Dose Reference Coefficient (300A,010C)

Final Dose Value

Dose Value Purpose (300A,061D) / Dose Value Interpretation (300A,068B)

Final value of Cumulative Dose Reference Coefficient (300A,010C)

Final Dose Value

Dose Value Purpose (300A,061D) / Dose Value Interpretation (300A,068B)

Beam 1

1.2 Gy

1.0

1.2 Gy

1.1476

1.3771 Gy

Beam 2

0.8 Gy

1.0

0.8 Gy

1.00175

0.8014 Gy

Sum

2.0 Gy

TRACKING / NOMINAL

2.1785 Gy

QA / ACTUAL

Sum x Fractions

20.0 Gy

21.785 Gy


DICOM PS3.3 2024a - Information Object Definitions