ESTRO 2024 - Abstract Book

S3393

Physics - Detectors, dose measurement and phantoms

ESTRO 2024

original

97.4

50.4

45.7

CBCT positioned

95.3

-2.1

50.4

0.1

44.6

2.5

T->G: 1cm

84.7

-11.1

49.3

2.1

42.1

5.6

T->G: 2cm

77.4

-8.6

48.1

2.4

39.6

5.8

T->G: 4cm

66.3

-14.4

43.4

9.8

34.9

12.0

T->G: 6cm

62.3

-6.0

40.4

6.8

31.7

9.1

Tab.1: Results of 3D In-Vivo Dosimetry Analysis, comparing planned treatment with outcomes under conditions of misalignment. 'T->G' denotes longitudinal table movement toward the gantry.

Conclusion:

This study demonstrates the efficacy of EPID-based IVD in enhancing the accuracy and safety of radiation therapy. By successfully identifying even minor treatment discrepancies, the automated system provides an additional safety layer, verifying that the actual treatment aligns with the planned procedure. Given the automatable nature of EPID IVD and the wide availability of the necessary hardware, implementing this advanced approach could substantially increase patient safety without demanding significant additional resources or workflow disruptions.

Keywords: In-Vivo, Automation, Patient Safety

References:

[1] Bojechko C, Phillps M, Kalet A, Ford EC. A quantification of the effectiveness of EPID dosimetry and software based plan verification systems in detecting incidents in radiotherapy. Med Phys 2015;42:5363–9. https://doi.org/10.1118/1.4928601.

[2] MacDougall ND, Graveling M, Hansen VN, Brownsword K, Morgan A. In vivo dosimetry in UK external beam radiotherapy: current and future usage. Br J Radiol 2017;90:20160915. https://doi.org/10.1259/bjr.20160915.

[3] Derreumaux S, Etard C, Huet C, Trompier F, Clairand I, Bottollier-Depois J-F, et al. Lessons from recent accidents in radiation therapy in France. Radiat Prot Dosimetry 2008;131:130–5. https://doi.org/10.1093/rpd/ncn235.

[4] Mijnheer BJ, González P, Olaciregui-Ruiz I, Rozendaal RA, van Herk M, Mans A. Overview of 3-year experience with large-scale electronic portal imaging device-based 3-dimensional transit dosimetry. Pract Radiat Oncol 2015;5:e679-687. https://doi.org/10.1016/j.prro.2015.07.001. [5] Bossuyt E, Weytjens R, Nevens D, De Vos S, Verellen D. Evaluation of automated pre-treatment and transit in vivo dosimetry in radiotherapy using empirically determined parameters. Phys Imaging Radiat Oncol 2020;16:113– 29. https://doi.org/10.1016/j.phro.2020.09.011. [6] Bossuyt E, Nevens D, Weytjens R, Taieb Mokaddem A, Verellen D. Assessing the impact of adaptations to the clinical workflow in radiotherapy using transit in vivo dosimetry. Phys Imaging Radiat Oncol 2023;25:100420. https://doi.org/10.1016/j.phro.2023.100420.