ESTRO 2024 - Abstract Book

S3481

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

Table 1: The average fraction of penumbra dose, expressed as a percentage, is presented for the Body, Planning Target Volume (PTV), and a chosen Organ at Risk (OAR) across all plans, categorized by varying complexities. For the prostate and gynecological plans rectum has been selected as an example OAR, while for the lung and head & neck the spinal cord and contralateral parotid has been chosen respectively.

Treatment plan

Body

PTV

OAR

Simple Clinical

Complex Simple Clinical Complex Simple

Clinical

Complex

Prostate 1

5.4

7.7

10.3

4.1

22.9

41.5

17.1

24.2

30.9

Prostate 2

5.4

7.9

9

11.6

31.5

42.9

27.3

38.5

43

Prostate 3

6

7.2

8.5

21.8

34.2

50.3

35.2

38.1

37.5

Lung 1

6.5

8.8

10.4

12.6

30.3

43.2

24.5

34.6

37.9

Lung 2

6.9

8.5

13.7

7.3

14.1

40.9

17.9

23

33.7

Lung 3

6.2

9.2

12.2

6.4

23.6

45

20.3

27.5

38.6

Head & Neck 1

9

11.7

17.6

11.8

24.9

52.1

25.8

37.2

40.2

Head & Neck 2

8.9

16.7

19

9.7

38.4

46.7

24

35.5

37.5

Head & Neck3

7.2

10.4

12.7

12.5

29.4

44.8

28.9

41.5

42.8

Gynecological 1

8.3

11.2

18.8

8.4

16.4

37.8

15.7

20.9

34.6

Gynecological 2

6.7

10.3

13

5

28.1

43.8

22.7

38.7

47.6

Gynecological 3

5.2

6.3

11.4

10.9

16.6

40.4

16

21.9

38.7

Conclusion:

The proposed method functions as a tool for assessing the extent to which the dose to certain voxels is influenced by the penumbra. A link was established between increased complexity and increased mean fraction of penumbra dose. Therefore, this approach could be used to quantify the complexity of the treatment plan in 3D.

Keywords: VMAT, penumbra, complexity

References:

1. Gotstedt J, Karlsson Hauer A, Back A. Development and evaluation of aperture-based complexity metrics using film and EPID measurements of static MLC openings. Med Phys. Jul 2015;42(7):3911-21. doi:10.1118/1.4921733