Evaluation of adjuvant vaginal vault brachytherapy in early stage cervical cancer patients

Purpose: Adjuvant external beam radiotherapy (EBRT) was shown to decrease pelvic relapses in patients with an early stage cervical cancer and intermediate-risk histopathological prognostic factors, at the cost of increased bowel morbidity. We examined the feasibility and results of adjuvant brachytherapy alone as an alternative to EBRT in this situation. Patients and methods: Medical records of consecutive patients receiving adjuvant brachytherapy between 1991 and 2018 for an early stage cervical cancer were examined. Patients were included if they presented a pT1a2N0 or pT1b1N0 disease following radical colpohysterectomy. Adjuvant vaginal wall brachytherapy (without EBRT) was indicated because of a tumor size ≥ 2 cm and/or presence of lymphovascular space invasion (LVSI). Patients received 60 Gy to 5 mm of the vaginal wall, through low-dose or pulse-dose rate technique. Patients’ outcome was examined for disease control, toxicities and prognostic factors. Results: A total of 40 patients were included. Eight patients (20%) had LVSI, 26 patients (65%) had a tumor size ≥ 2 cm. With median follow-up time of 42.0 months, 90% of patients were in complete remission and four patients (10%) experienced tumor relapse, all in the peritoneal cavity, and associated with synchronous pelvic lymph node failure in 2/4 patients. No vaginal or isolated pelvic nodal failure was reported. At 5 year, overall survival was 83.6% (CI95%: 67.8–100%) and disease-free survival was 85.1% (CI95%: 72.6–99.9%). In univariate analysis, probability of relapse correlated with tumor size ≥ 3 cm (P = 0.004). No acute or late toxicity grade more than 2 was reported. Conclusion: Brachytherapy alone was a well-tolerated adjuvant treatment for selected patients with intermediate risk factors. The risk of relapse in patients with tumor size ≥ 3 cm was however high, suggesting that EBRT is more appropriate in this situation.