Intermediate-risk endometrial cancer treated with adjuvant brachytherapy using single dosimetric planning: long-term outcome and toxicity assessment

Abstract

Objective: Brachytherapy of the vaginal dome is the recommended adjuvant treatment for intermediate-risk endometrial cancer. This study assessed the results of dosimetric planning of high-dose-rate brachytherapy exclusively in the first treatment session.

Study design: This retrospective study included all patients who underwent hysterectomy for endometrial cancer followed by adjuvant brachytherapy of the vaginal dome between 2012 and 2015. Local recurrence rates, overall survival (OS) rates, recurrence-free survival (RFS) rates, and related acute and late toxicity rates were evaluated.

Results: This analysis included 250 patients, of whom 208 were considered to be at high-intermediate risk of disease recurrence. After a median follow-up of 56 months, the cumulative incidence of local recurrence was 4.8% at 3 years [95% confidence interval (CI) 2.8-8.3] and 7.8% at 5 years (95% CI 4.8-12.6). The 5-year OS rate was 86.2% (95% CI 80.6-90.3), and the 5-year RFS rate was 77.5% (95% CI 71.1-82.7). Acute toxicity occurred in 20 (8%) patients, of which two patients had grade ≥3 toxicity. Only one patient (0.4%) presented with late grade ≥3 toxicity.

Conclusion: These findings confirm the tolerability of this brachytherapy approach, indicating minimal cases of late grade ≥3 toxicity, associated with a good 5-year OS rate. With the advent of molecular prognostic factors, the current focus revolves around discerning those individuals who gain the greatest benefit from adjuvant therapy, and tailoring treatment more effectively.

Keywords: Endometrial cancer; Intermediate risk; Vaginal cuff brachytherapy.