Toxicity and Efficacy After Adjuvant Vaginal Brachytherapy Using 30 Gy in 6 Fractions for Stages I and II Endometrial Cancer

Purpose: This study aimed to evaluate outcomes and toxicity in patients with endometrial cancer per our institutional adjuvant vaginal cuff brachytherapy (VBT) fractionation scheme.Methods and Materials: We identified women with International Federation of Gynecology and Oncology stages I and II endometrial cancer who underwent surgical staging and adjuvant high-dose-rate VBT without external beam radiation. All patients received 30 Gy in 6 fractions to the upper one-third of the vagina, prescribed to a depth of 5 mm and delivered twice weekly. Toxicities were prospectively elicited at each follow up, and rates of recurrence and survival were retrospectively assessed.Results: We identified 247 eligible patients treated between 1992 and 2018 with a median follow up of 5.8 years (range, 0.1-24.7 years). Most patients had stage I disease (52% stage IA; 37% stage IB), and 11% of patients were stage II. Deep myometrial invasion was predictive of local recurrence (P=.002). The 5-year rates of local recurrence, regional recurrence, and distant metastases were 5%, 5%, and 7%, respectively. Five-year overall and disease-free survival were 91% and 83%, respectively. The most common grade 1 toxicities were acute fatigue (11% crude rate), urinary frequency (11%), chronic (> 6 months) urinary frequency (13%), urinary incontinence (13%), and vaginal stenosis (21%). There were few grade 2 toxicities (all < 5%) and no grade 3 to 5 toxicities.Conclusions: The adjuvant VBT fractionation scheme of 30 Gy in 6 fractions results in low rates of toxicity, with no grade >= 3 adverse events, and local control rates comparable with those from other published series using different fractionation schemes. (C) 2021 The Authors. Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.