ESTRO 2025 - Abstract Book

S491

Clinical - Breast

ESTRO 2025

without breast reconstruction. Less evidence supports efficacy and safety of HFPMRT in patients with reconstruction. This meta-analysis of randomized controlled trials (RCTs) aims to provide a comparative evaluation of HFPMRT versus CFPMRT in patients with or without reconstruction. Material/Methods: Relevant studies were identified systematically by searching OVID Medline, Embase, Web of Science, Scopus and ClinicalTrials.gov up to Nov 4, 2024. RCTs comparing HFPMRT and CFPMRT in females undergoing mastectomy with or without reconstruction were included. Conference proceedings of ASTRO and ESTRO annual meetings 2023 and 2024 were also reviewed. Two investigators (BG and YW) independently screened results using PRISMA guidelines. Local recurrence was assessed in all selected trials. Chest wall reconstruction complication was assessed in trials with reconstruction and skin toxicity was assessed in trials without reconstruction. Results: From 996 studies, 11 randomized controlled trials with low risk of bias were included, encompassing a total of 2786 patients. There was no significant difference in locoregional recurrence between HFPMRT and CFPMRT (OR=0.90, 95% CI: 0.63 – 1.30, P=0.90), with low heterogeneity (I 2 = 0) across studies. Among seven trials of PMRT without reconstruction (1401 patients), HFPMRT demonstrated reduced Grade 3 acute skin toxicity compared to CFPMRT (OR=0.30, 95% CI: 0.11 – 0.78, P=0.04, I 2 =54%). Among three trials of PMRT with reconstruction encompassing 1288 patients, there was no significant difference in the rates of chest wall complications between HFPMRT and CFPMRT (OR=1.10, 95% CI: 0.80 – 1.51, P=0.54, I 2 =0%).