ESTRO 2025 - Abstract Book

S227

Brachytherapy - Gynaecology

ESTRO 2025

9 Department of Medical Physics, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum University of Bologna, Bologna, Italy

Purpose/Objective: This systematic review aims to assess the feasibility, safety, and efficacy of using modern external beam radiotherapy (EBRT) techniques, such as intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic body radiotherapy (SBRT), as alternatives to brachytherapy (BRT) in the treatment of endometrial cancer (EC). Material/Methods: A multidisciplinary team conducted a systematic review following PRISMA guidelines. The research question was framed using the PICO method, focusing on patients with EC [P], comparing modern EBRT techniques (IMRT, VMAT, SBRT) [I] against BRT [C] to evaluate their feasibility, safety, and effectiveness, particularly in terms of tumor local control (LC) [O]. The review included English-language studies exploring EBRT as a replacement for BRT in EC treatment. Both planning and clinical outcomes, including acute toxicity, late side effects, and LC, were analyzed, with quality assessments performed using the GRADE framework and ROBINS-I tool. Results: Out of 486 publications, 11 studies met the inclusion criteria. Planning studies revealed that while IMRT and VMAT provided comparable or improved target coverage and dose homogeneity compared to BRT, BRT was associated with lower doses to critical organs such as the bladder and femoral heads. Clinical outcomes varied, with one study showing a modest 18-month LC rate of 41% for SBRT in exclusive EC treatment, while postoperative SBRT and SIB VMAT studies reported high LC rates (up to 100%) with minimal acute toxicity. However, concerns about late toxicity persisted, particularly with SBRT. The overall quality of evidence was low to very low, with significant risks of bias, particularly related to participant selection.