ESTRO 2025 - Abstract Book

S2687

Physics - Dose calculation algorithms

ESTRO 2025

Conclusion: A dramatic reduction of desorption probabilities was found with increasing source depth parameter. The absorbed dose delivered over the treatment period has a significant dependence on the source construction and the 220 Rn and 212 Pb desorption off the surface of the seed.

Keywords: DaRT, alpha particles, brachytherapy, dosimetry

References: 1. Heger G, Roy A, Dumančić M, et al. Alpha dose modeling in diffusing alpha ‐ emitters radiation therapy—Part I: single ‐ seed calculations in one and two dimensions. Med Phys . 2023;50:1793–1811. 2. Ballisat L, De Sio C, Beck L, et al. Dose and DNA damage modelling of diffusing alpha-emitters radiation therapy using Geant4. Physica Medica . 2024;121:103367. 3. Arazi L. Diffusing alpha-emitters radiation therapy: approximate modeling of the macroscopic alpha particle dose of a point source. Phys Med Biol . 2020;65:015015. 4. Khan AU, Jollota S, DeWerd LA. A diffusion ‐ leakage model coupled with dose point kernels (DPK) for dosimetry of diffusing alpha ‐ emitters radiation therapy (DaRT). Med Phys . 2024;51:3725–3733.

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Digital Poster Sensitivity analysis of beam rise time in dose-driven continuous scanning for Hitachi Proton Therapy System at National Cancer Centre Singapore Kang Hao Lee 1 , Clifford Ghee Ann Chua 1 , Kah Seng Lew 1 , Calvin Wei Yang Koh 1 , Andrew Wibawa 1 , Zubin Master 1 , James Cheow Lei Lee 1,2 , Sung Yong Park 1,3 , Hong Qi Tan 1,2 1 Department of Radiation Oncology, National Cancer Centre Singapore, Singapore, Singapore. 2 Division of Physics and Applied Physics, Nanyang Technological University, Singapore, Singapore. 3 Oncology Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore Purpose/Objective: In proton pencil beam scanning, the Dose-Driven Continuous Scanning (DDCS) technique allows continuous beam delivery between spots, potentially reducing treatment time compared to Discrete Spot Scanning (DSS). For DDCS,