ESTRO 2025 - Abstract Book

S1159

Clinical – Lower GI

ESTRO 2025

764

Digital Poster Optimizing Outcomes in Locally Advanced Rectal Cancer: Watch-and-Wait Strategy with Hypofractionated Radiotherapy and Integrated Boost Carmen Saiz, Ovidio Hernando-Requejo, Mercedes López, Emilio Sanchez, Angel Montero, Jaennette Valero, Beatriz Álvarez, Bruno Esteban Zambana, Mariola García-Aranda, Raquel Ciérvide, Miguel Sánchez, Carmen Rubio Department of Radiation Oncology, University Hospital HM Sanchinarro, Madrid, Spain

Purpose/Objective: To evaluate the efficacy and safety of total neoadjuvant treatment (TNT) with dose-escalating radiotherapy, followed by surgery or W&W, in locally advanced rectal adenocarcinoma, assessing LC, PFS, OS, toxicity, and prognostic factors.

Material/Methods:

This retrospective, single-center study included 136 patients treated from January/2015 to October/2024. Patients received TNT, with either induction or consolidation chemotherapy, dose-escalated radiotherapy and followed by Surgery or W&W. Demographic, therapeutic, and dosimetric variables were analyzed for their influence on outcomes.

Results: