ESTRO 2024 - Abstract Book

S4683

Physics - Optimisation, algorithms and applications for ion beam treatment planning

ESTR0 2024

Alternatively, as investigated in this work, an online adaptive workflow could be employed to guarantee adequate coverage while reducing the 2-years mortality risk by 6 percentage points.

Keywords: setup robustness settings, online plan adaptation

References:

1. Van Herk M, Remeijer P, Rasch C, Lebesque J V. The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy. Int J Radiat Oncol Biol Phys. 2000;47(4).

2. Addendum slokdarmcarcinoom bij landelijk indicatie protocol protonentherapie longcarcinoom. 2021. [cited 2023 Oct 20] Available from: https://nvro.nl/publicaties/rapporten.

3. Defraene G, Dankers F, Price G, Schuit E, van Elmpt W, Arredouani S, et al. Multifactorial risk factors for mortality after chemotherapy and radiotherapy for non-small cell lung cancer. Radiother Oncol. 2019.

2365

Digital Poster

Dosimetric evaluation of proton therapy for synthetic CT in an MRI-only workflow for prostate cancer

Kajsa M.L. Fridström 1,2 , René M. Winter 1 , Natalie Hornik 1,3 , Sigrun S. Almberg 2 , Signe Danielsen 1,2 , Kathrine R. Redalen 1

1 Norwegian University of Science and Technology, Department of physics, Trondheim, Norway. 2 St.Olavs Hospital, Cancer clinic, Trondheim, Norway. 3 Eberhard Karls University of Tübingen, Department of Radiation Oncology, Tübingen, Germany

Purpose/Objective:

Magnetic resonance imaging (MRI) only workflow and proton treatment are two appealing treatment possibilities in radiotherapy (RT). T2-weighted MRI enable precise target localization due to superior soft tissue contrast compared to the conventional computed tomography (CT) (1–3), while proton RT has excellent dose conformity and ability to spare normal tissue (4,5). Since MRI lacks information about electron density, which is needed in order to calculate radiation dose to the patient, it is necessary to generate a synthetic CT (sCT) in the MRI-only workflow (1). MRI-only workflow is used in photon RT of prostate cancer today, but not yet for protons. To bring MRI-guided RT into clinical use for proton RT, proton dose calculation on sCT needs to be validated. Our purpose was to perform a dosimetric evaluation of a commercial sCT software for proton RT plans. The results are benchmarked against similar evaluation for photon RT.

Material/Methods: