ESTRO 2025 - Abstract Book

S261

Brachytherapy - Gynaecology

ESTRO 2025

Conclusion: We found the variation of the steep dose gradient that characterizes the brachytherapy dose distribution significantly affects the TCP and can be influenced by anatomical parameters, such as target volume and distance to OARs. Based on these preliminary results, target delineation uncertainties could potentially affect also the dose distribution gradient. Further analyses are ongoing on a larger dataset.

Keywords: dose gradient, TCP, plan optimization

3422

Digital Poster Outcomes in Locally Advanced Cervical Cancer FIGO IIIC treated by Radiochemotherapy and image guided adaptive Brachytherapy in pre immunotherapy era. Abel Cordoba 1 , Gregoire Laurent Delanghe 1 , Severine Risbourg 2 , Diane Sayadi 1 , Alexandra Noeuveglise 1 , Carlos Martinez Gomez 3 , Delphine Hudry 3 , Lucie Bresson 3 , Marie-Cecile Le Deley 2 , Romain Cayez 4 , Mohamed Tahar Ladjimi 4 , Eric F Lartigau 1 , Fabrice Narducci 3 1 Radiotherapy, Centre Oscar Lambret, Lille, France. 2 Methodology and Biostatistics, Centre Oscar Lambret, Lille, France. 3 Surgical Oncology, Centre Oscar Lambret, Lille, France. 4 Medical Physics, Centre Oscar Lambret, Lille, France Purpose/Objective: To evaluate local control and disease free survival (DFS) in a population of locally advanced cervical cancer (LACC) FIGO 2018 IIIC treated by definitive radiochemotherapy (RCT) followed by image guided adaptive brachytherapy (IGABT). Material/Methods: This retrospective study included all women with FIGO IIIC LACC treated in our center between 01-2016 and12-2021. All patients had positive pelvic lymph nodes. For patients with negative aortic PET-SCAN staging, para-aortic lymphadenectomy (PAL) was planned to determinate radiations field. Treatment was completed by RCT and IGABT. Outcomes analyzed included the cumulative incidence of local progression/relapse estimated using Kalbfleisch and