Brachytherapy for the Conservative Treatment of Female Peri-Urethral Carcinoma

Simple Summary Para-urethral gynecological tumors pose significant therapeutic challenges due to the expected morbidity of surgery, especially when the tumor is close to the urethra. There is little data to guide management. Most of the available data have focused solely on the treatment of primary vaginal tumors, and few publications provide guidance for the treatment of vaginal recurrences of other gynecologic cancers (e.g., cervix, endometrium). We report on the feasibility of interstitial brachytherapy, as an exclusive treatment combined with external radiotherapy, for the conservative treatment of para-urethral tumors, with high local control probability. Introduction: Peri-urethral cancers (PUC) are rare tumors. Brachytherapy (BT), either monotherapy or combined with radiation therapy, is a preferred treatment option to spare the morbidity of surgery and achieve organ preservation. We report, to the best of our knowledge, the largest experience of brachytherapy among women with PUC. Patients and Methods: This is a retrospective review of the medical records of female patients with PUC who underwent low- or pulse-dose-rate BT with or without external beam radiotherapy at Gustave Roussy between 1990 and 2018. Patients were categorized according to the treatment intention into a primary and recurrent group. The Kaplan-Meier method was used for survival analysis, and the Cox proportional-hazard model was used for univariate analysis. Brachythewharapy-related adverse events were reported according to Common Terminology Criteria for Adverse Events version 4. Results: We identified 44 patients with PUC who underwent BT. Of the 44 patients, 22 had primary tumors and 22 had recurrent tumors. Histologies were mainly adenocarcinoma (n = 20) and squamous cell carcinoma (n = 14). The median prescribed dose was 60 Gy for the 24 patients treated with BT alone and 20 Gy (IQ range: 15-56.25 Gy) for the 20 patients treated with BT in combination with EBRT. With a median follow-up of 21.5 months (range 7.5-60.8), a total of six patients experienced local relapse (17.5%). The 2-year overall survival probability was 63% (95%CI: 49.2-81.4%). The most common toxicities were acute genito-urinary grade 1-2 toxicities. At the last follow-up, four patients experienced focal necrosis. Conclusions: In this cohort of women with PUC undergoing BT, we observed an 80% probability of local control with acceptable morbidity. Though survival was poor, with high metastatic relapse probability, BT was useful to focally escalate the dose and optimize local control in the context of an organ sparing strategy.