ESTRO 2025 - Abstract Book

S2704

Physics - Dose calculation algorithms

ESTRO 2025

Conclusion: Monte Carlo simulation is considered the gold standard of dose calculation and for the patients studied there was a major deviation from the dose calculated by the TPS. Even though retrospective institutional outcomes suggest improved local control and overall survival compared to patients treated with surgery alone, it is of paramount importance to obtain accurate clinical dose calculation to understand the effects of dose and outcomes.

Keywords: Brain Brachytherapy, Low Energy, Monte Carlo

References: Alshreef, A., Rogers, B., Oare, C., Ferreira, C. (2025) Validation of GAMOS Monte Carlo simulation for 131 Cs brachytherapy source in water and dosimetric characterization of solid water, bone, and brain tissues. doi: 10.1016/j.radphyschem.2024.112268 Gessler, D. J., et al (2021). GammaTile® brachytherapy in the treatment of recurrent glioblastomas. Neuro-Oncology Advances, 4(1), vdab185. PMID: 35088050 PMCID: PMC8788013 doi: 10.1093/noajnl/vdab185 Ferreira, C., et al (2021). Commissioning and Clinical Aspects of First Commercial Implementation of Cs-131 GammaTile Permanent Brain Implants. Brachytherapy, 20(3), 673-685. https://doi.org/10.1016/j.brachy.2020.12.005

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Digital Poster Impact of the Enhanced Leaf Model (ELM) for the MLC on X6 Photon Beam Configuration in the Eclipse Treatment Planning System Sounya Ait chikh 1,2 , Samir Bencheikh 1 , Ryma Louelh 1 , Billal Metchat 1 , Abdelkader Toutaoui 1 1 Radiotherapy, hopital chahid's mahmoudi, tizi ouzou, Algeria. 2 physique, Université des Sciences et de la Technologie Houari Boumediene, alger, Algeria Purpose/Objective: The introduction of the MLC model (Enhanced Leaf Model, ELM) into the Eclipse treatment planning system represents a significant advancement. In earlier versions of Eclipse, particularly version 15.3 that we previously used, dose calculation modeling and implementation relied solely on the MLC transmission factor and the DLG (Dynamic Leaf Gap), introduced as parameters. With the newly installed version 18.011, the configuration of the ELM MLC model is now incorporated into beam configuration. This has led to notable changes, especially in the secondary source and other parameters related to dose calculation