Purpose: Intravaginal high-dose-rate brachytherapy is an effective adjuvant treatment for localized endometrial carcinoma. However, relatively little is known about risk factors of post-treatment vaginal stenosis (VS).
Methods and materials: We included patients treated with brachytherapy for endometrial carcinoma from September 2011 to January 2014 with at least 3 months of followup. Patients who received external beam radiation therapy were excluded. VS was prospectively graded at each followup visit per Common Terminology Criteria for Adverse Events, version 4.03. χ(2) and t test analyses were used to assess the association of VS with various patient, tumor, treatment, and post-treatment factors. Multivariable logistic regression analysis was used to identify independent predictors of VS Grade ≥1 and ≥2.
Results: All 101 patients were disease free at last followup. Mean followup was 12.9 months (range, 3-34). Highest VS grades were zero in 67%, one in 26%, two in 6%, and three in 1%. Borderline significant variables associated with Grade ≥1 VS included vagina length, proportion of vagina treated, and total dose. Dilator use was significantly associated with Grade ≥2. Multivariable analysis revealed that proportion of vagina treated >60% (odds ratio [OR], 3.48; p = 0.009) and total dose >14 Gy (OR, 4.27; p = 0.015) were independent predictors of Grade ≥1 VS, and lack of consistent dilator use was an independent predictor of Grade ≥2 VS (OR, 5.60; p = 0.047).
Conclusions: Patients treated with a higher total dose to a larger proportion of the vagina were more likely to develop Grade ≥1 VS. Consistent dilator use may also be protective against Grade ≥2 VS.
Keywords: Brachytherapy; Endometrial cancer; High-dose-rate; Toxicity; Vaginal stenosis.
Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.