ESTRO 2025 - Abstract Book

S339

Brachytherapy - Physics

ESTRO 2025

Keywords: Prospective Study, AI Delineation, Timegain

References: [1] Lim JY, Leech M. Use of auto-segmentation in the delineation of target volumes and organs at risk in head and neck. Acta Oncol 2016;55:799–806. [2] Shi F, et al. Deep learning empowered volume delineation of whole-body organs-at-risk for accelerated radiotherapy. Nat Commun 2022;13:6566. [3] Isensee F, et al. nnU-Net: a self-configuring method for deep learning-based biomedical image segmentation. Nat Methods 2021;18:203–11. [4] Pötter R, et al. The EMBRACE II study: The outcome and prospect of two decades of evolution within the GEC-ESTRO GYN working group and the EMBRACE studies. Clin Transl Radiat Oncol 2018;9:48–60.

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Digital Poster Dosimetric Evaluation of HDR Interventional Radiotherapy (Brachytherapy), VMAT, and Electron Beam Therapy for Non-Melanoma Skin Cancer Elisa Placidi 1 , Enrico Rosa 1,2 , Bruno Fionda 3 , Valentina Lancellotta 3 , Antonio Napolitano 4 , Martina De Angeli 3 , Maria Vaccaro 4 , Maria Concetta La Milia 5 , Pierpaolo Dragonetti 3,5 , Francesco Pastore 6 , Leonardo Bannoni 3 , Vincenzo Frascino 6 , Maria Antonietta Gambacorta 6,5 , Luca Tagliaferri 3,5 , Marco De Spirito 1,7 1 UOC Fisica per le Scienze della Vita, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy. 2 Department of Theoretical and Applied Sciences, eCampus University, Novedrate, Italy. 3 UOC Degenze di Radioterapia Oncologica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy. 4 Medical Physics Unit, Bambino Gesù Children’s Hospital, Rome, Italy. 5 Istituto di Radiologia, Università Cattolica del Sacro Cuore, Rome, Italy. 6 UOC Servizio di Radioterapia Oncologica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy. 7 Istituto di Fisica, Università Cattolica del Sacro Cuore, Rome, Italy Purpose/Objective: This study aims to compare the dosimetric outcomes of high-dose-rate (HDR) interventional radiotherapy (IRT, Brachytherapy, BT), Volumetric Modulated Arc Therapy (VMAT), and electron beam therapy in treating non melanoma skin cancer (NMSC). By analyzing various techniques, we intend to provide insights for optimizing treatment plans and improving clinical outcomes for NMSC patients [1].

Material/Methods:

A retrospective analysis was conducted on 25 NMSC patients treated with HDR 192Ir IRT at our institution. Dosimetric parameters, including Dmean for the clinical target volume (CTV), V95%CTV, and D2cc for organs at risk (OAR), were calculated for each modality. HDR IRT was planned using the Freiburg applicator with a Flexitron afterloader (Elekta) and evaluated using the TG-186 algorithm in Oncentra Brachy TPS [2]. VMAT and electron beam plans were simulated using the Eclipse TPS (Varian). The mean dose to the CTV, dose-volume histogram (DVH) metrics, and dose profiles were compared among the techniques.