ESTRO 2025 - Abstract Book

S2680

Physics - Detectors, dose measurement and phantoms

ESTRO 2025

Results The measured gamma passing rate was over 95%. All measurements were performed about 2 minutes, a 75% less time than with diamond detector and typical WP parameters.

Conclusion The Blue Physics Model 10 PSD is capable of perform ultrafast measurements without losing quality and shortening the time required for dosimetric commissioning.

Keywords: Ultrafast, commissioning, scintillating detector

References Ferrer, Carlos, et al. "Dosimetric characterization of a novel commercial plastic scintillation detector with an MR ‐ Linac." Medical Physics 50.4 (2023): 2525-2539. Das, Indra J., et al. "Characteristics of a plastic scintillation detector in photon beam dosimetry." Journal of Applied Clinical Medical Physics 25.1 (2024): e14209.

4485

Poster Discussion Radioluminescence 3D Dose Reconstruction for FLASH Radiotherapy using the Abel Transform Stefano Pizzardi 1 , Lisa Alborghetti 1 , Federica Vurro 1 , Maria Assunta Lacavalla 1 , Macrina Milani Capialbi 1 , Fabio Di Martino 2 , Luigi Masturzo 2 , Andrea Cavalieri 2 , Claudio Fiorino 3 , Antonello E. Spinelli 1 1 Experimental Imaging Centre, IRCCS San Raffaele Scientific Institute, Milan, Italy. 2 Center for Instrument Sharing, University of Pisa (CISUP), Pisa, Italy. 3 Medical Physics Department, IRCCS San Raffaele Scientific Institute, Milan, Italy Purpose/Objective The emergence of FLASH radiotherapy has highlighted the need for innovative dosimeters that can overcome limitations of conventional dosimeters, such as slow readout times, saturation at high dose rates and limited linearity [1]. Radioluminescence imaging (RLI) using plastic (water equivalent) scintillators offers a promising alternative, providing real-time response, high spatial resolution and a broad dynamic dose range [2][3]. This study presents the development of a real-time dosimetry system capable of reconstructing 3D dose distributions from scintillation light, with comparison against Monte Carlo (MC) simulations and Gafchromic (GC) film measurements. Material/Methods RLI was performed using a plastic scintillator cube (EJ 200, 5×5×5 cm³) and a CMOS detector system (Prime BSI Express, 2048×2048 pixels, 6.5 µm pixel size) with an F=1.4, 8 mm C-mount lens. Measurements were conducted on a 9 MeV FLASH electron linac (Electron Flash, SIT Sordina) using a 1 cm diameter circular beam collimator. The CMOS detector was positioned laterally to capture the side view of the cube, allowing the detection of the radioluminescence signal within the cube volume. The emitted scintillation photons, proportional to the deposited