Intraoperative Electron Beam Radiation Therapy (IOERT) Versus High-Dose-Rate Intraoperative Brachytherapy (HDR-IORT) in Patients With an R1 Resection for Locally Advanced or Locally Recurrent Rectal Cancer

Purpose Intraoperative radiation therapy (IORT), delivered by intraoperative electron beam (IOERT) or high-dose-rate brachytherapy (HDR-IORT), may reduce the local recurrence rate in patients with locally advanced and recurrent rectal cancer (LARC LRRC, respectively). The aim of this study was to compare oncological outcomes between both IORT modalities LARC LRRC who underwent a microscopic irradical (R1) resection. Methods All consecutive received because an R1 resection 2000 2016 two tertiary referral centers were included. In LARC, margin ?2 mm considered R1. A 0 LRRC. Results total, 215 included, whom 151 (70%) IOERT 64 (30%) HDR-IORT; addition, 158 112 (71%) 46 (29%) HDR-IORT. After multivariable analyses, overall survival not significantly different modalities. recurrence-free longer treated HDR-IORT, (hazard ratio [HR], 0.496; 95% CI, 0.253-0.973; P = .041) (HR, 0.567; 0.349-0.920; .021). major postoperative complications similar for (IOERT, 30%; 27%), whereas incidence higher after HDR-IORT 26%; 46%). Conclusions: This showed better favor Optimization technique seems warranted.