Bevacizumab increases late toxicity in re-irradiation with image-guided high-dose-rate brachytherapy for gynecologic malignancies

INTRODUCTION: Patients with recurrent gynecologic malignancies having had pelvic irradiation, generally have limited salvage options. This study investigated patients with gynecologic malignancies, who had a history of pelvic irradiation and received salvage re-irradiation using image-guided high-dose-rate brachytherapy (IG-HDR-BT). MATERIAL AND METHODS: Patients with gynecologic malignancies, who had a history of previous irradiation and received re-irradiation using IG-HDR-BT for disease recurrences from June 2014 to March 2020 were included in this study. RESULTS: A total of 37 patients were included in this retrospective analysis. Primary tumor was uterine cervical cancer in 31 patients, endometrial cancer in 5 patients, and vaginal cancer in 1 patient. Median follow-up period of patients who were alive at the time of analysis was 15.4 months (range, 4.1-61.4 months). Two-year overall survival, progression-free survival, and local control were 68.9%, 49.3%, and 67.5%, respectively. Severe late toxicities ≥ grade 3, which were related to re-irradiation, were observed in 9 patients (24.3%). Usage of bevacizumab in the entire course of treatment was associated with development of late ≥ grade 3 fistula formation, bowel perforation, or vaginal ulcer (50% vs. 6.9%, p = 0.013). Tumor size ≥ 2.5 cm was associated with development of late ≥ grade 3 of rectum, bladder, or vaginal toxicities (0% vs. 28%, p = 0.047). CONCLUSIONS: If the recurrent disease was found in small size and there was no history of bevacizumab usage, re-irradiation with IG-HDR-BT could be considered, even in patients with a previous history of pelvic irradiation.