Outcome of intraoperative brachytherapy as asalvage treatment for locally recurrent rectal cancer.

Abstract

Locally advanced recurrent rectal cancer (RRC) requires amultimodal approach. Intraoperative high-dose-rate brachytherapy (HDR-BT) may reduce the risk of local recurrence. However, the optimal therapeutic regimen remains unclear. The aim of this retrospective monocentric study was to evaluate the toxicity of HDR-BT after resection of RRC. Between 2018 and 2022, 17patients with RRC received resection and HDR-BT. HDR-BT was delivered alone or as an anticipated boost with amedian dose of 13 Gy (range 10-13 Gy) using an 192iridium microSelectron HDR remote afterloader (Elekta AB, Stockholm, Sweden). All participants were followed for assessment of acute and late adverse events using the Common Terminology Criteria for Adverse Events version5.0 and the modified Late Effects in Normal Tissues criteria (subjective, objective, management, and analytic; LENT-SOMA) at 3‑ to 6‑month intervals. Atotal of 17patients were treated by HDR-BT with median dose of 13 Gy (range 10-13 Gy). Most patients (47%) had an RRC tumor stage of cT3‑4 N0. At the time of RRC diagnosis, 7patients (41.2%) had visceral metastases (hepatic, pulmonary, or peritoneal) in the sense of oligometastatic disease. The median interval between primary tumor resection and diagnosis of RRC was 17months (range 1-65months). In addition to HDR-BT, 2patients received long-course chemoradiotherapy (CRT; up to 50.4 Gy in 1.8-Gy fractions) and 2patients received short-course CRT up to 36 Gy in 2‑Gy fractions. For concomitant CRT, all patients received 5‑fluorouracil (5-FU) or capecitabine. Median follow-up was 13months (range 1-54). The most common acute grade1-2 toxicities were pain in 7patients (41.2%), wound healing disorder in 3patients (17.6%), and lymphedema in 2patients (11.8%). Chronic toxicities were similar: grade1-2 pain in 7patients (41.2%), wound healing disorder in 3patients (17.6%), and incontinence in 2patients (11.8%). No patient experienced agrade ≥3 event. Reirradiation using HDR-BT is well tolerated with low toxicity. An individualized multimodality approach using HDR-BT in the oligometastatic setting should be evaluated in prospective multi-institutional studies.