Dosimetric Characterization and Workflow Optimization of the FLASH-SARRP for Reliable Preclinical Radiobiological Studies

Knol, M.; Goncalves Jorge, P.; Kunz, L. V.; Korysko, P.; Petit, B.; Durham, A.; Marie-catherine, V.; Tsoutsou, P.; Koutsouvelis, N.; Lascaud, J.

doi:10.64898/2026.07.06.736680

bioRxiv · 10.64898/2026.07.06.736680

Dosimetric Characterization and Workflow Optimization of the FLASH-SARRP for Reliable Preclinical Radiobiological Studies

Knol, M.·Goncalves Jorge, P.·Kunz, L. V.·Korysko, P.·Petit, B.·Durham, A.·Marie-catherine, V.·Tsoutsou, P.·Koutsouvelis, N.·Lascaud, J.

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Abstract

ObjectivePreclinical small-animal irradiators such as the FLASH-SARRP can support the advancement of photon-FLASH toward the clinic. This study aimed at characterizing the FLASH-SARRP and established a robust quality assurance (OA) workflow to enable accurate and reproducible preclinical experiments. ApproachCustom 3D-printed spacers were designed to ensure reproducible X-ray tube alignment, sample positioning and mounting of the dosimetric tools. Beam characteristics were evaluated using a combined dosimetric approach. High spatially resolved dose distributions were obtained from Gafchromic films, whereas a plastic scintillating fiber was employed to monitor in real-time the temporal pulse structure and synchronization between the two X-ray tubes. Day-to-day variability of the delivery was evaluated over several sessions. Main resultsThe FLASH-SARRP achieved dose-rates of around 80 Gy/s when both tubes were used simultaneously and provided a homogeneous irradiation field suitable for small-animal studies. A desynchronization between the two tubes was observed with an average delay of 10 ms, resulting in temporal dose-rate heterogeneity. Additionally, a substantial inter-session variability ([~]11%) was found, whereas the intra-session variability was relatively low ([~]4%). Inter-session variability was reduced to 5%, approaching the intra-session variability, by adding Gafchromic films/scintillator-based quality assurance (OA) workflow into the irradiation routine. SignificanceThis work highlights the importance of temporal dosimetry for preclinical FLASH studies. Additionally, a practical OA framework is proposed integrating real-time monitoring with reference dosimetry. The proposed work enables adaptive dose delivery, thereby enhancing the reproducibility of the irradiations, which is crucial for reliable preclinical studies on the FLASH effect.

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Knol, M., Goncalves Jorge, P., Kunz, L. V., Korysko, P., Petit, B., Durham, A., Marie-catherine, V., Tsoutsou, P., Koutsouvelis, N., Lascaud, J.. 2026-07-07. Dosimetric Characterization and Workflow Optimization of the FLASH-SARRP for Reliable Preclinical Radiobiological Studies. https://doi.org/10.64898/2026.07.06.736680

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