ESTRO 2025 - Abstract Book

S2588

Physics - Detectors, dose measurement and phantoms

ESTRO 2025

Conclusion: OCDA, TCDA, and PCDA crystals are viable materials for radiochromic dosimeters. While the hydrophobic side chain length does affect the dosimetric behaviour of these diacetylenes, the interaction is more complex and can’t be described by chain lengths alone with no distinct trend observed over this limited investigated alkyl chain length.

Keywords: Radiochromic, Real-time , Dosimetry

References: 1.

Rink A, Lewis DF, Varma S, Vitkin IA, Jaffray DA. Temperature and hydration effects on absorbance spectra and radiation sensitivity of a radiochromic medium. Med Phys. 2008;35(10):4545-4555. doi:10.1118/1.2975483 2. Niroomand-Rad A, Blackwell CR, Coursey BM, et al. Radiochromic film dosimetry: Recommendations of AAPM Radiation Therapy Committee Task Group 55. Med Phys. 1998;25(11):2093-2115. doi:10.1118/1.598407 3. Kaiyum R, Schruder CW, Mermut O, Rink A. Role of water in the crystal structure of LiPCDA monomer and the radiotherapy dose response of EBT-3 film. Med Phys. 2022;49(5):3470-3480. doi:10.1002/mp.15597

1922

Poster Discussion Dosimetric Assessment in Preclinical Spatially Fractionated Radiotherapy (SFRT) with a FLASH Compact X ray Source

Paolo Pellicioli, Cristian Fernandez-Palomo, Valentin Djonov Institute of Anatomy, University of Bern, Bern, Switzerland

Purpose/Objective: Spatially fractionated radiotherapy (SFRT) using sub-millimetric wide beams is gaining renewed interest in radio oncology due to its ability to deliver heterogeneous high-dose fields that enhance tumor control by stimulating T cell infiltration (Trappetti et al. 2024) while sparing healthy tissues (Potez et al. 2018, Wright 2021, Laissue et al 2021). This approach has spurred research toward preclinical X-ray sources capable of delivering these treatments. The Xstrahl CIX FLASH system is a compact X-ray source that can deliver homogeneous radiation fields with dose rates up to 100 Gy/s. Adapted at the Institute of Anatomy, University of Bern, Switzerland, the system is used for preclinical SFRT studies, with dose rates up to 20 Gy/s.