Brachytherapy Combined With Surgery for Conservative Treatment of Children With Bladder Neck and/or Prostate Rhabdomyosarcoma

Purpose To report the results of a conservative strategy based on partial surgery combined with brachytherapy in a prospective cohort of children with bladder–prostate rhabdomyosarcoma (BP RMS). Methods and Materials We prospectively documented the outcome of children treated in our department between 1991 and 2015 for BP RMS and undergoing a multimodal approach combining conservative surgery (partial cystectomy and/or partial prostatectomy) and perioperative interstitial low-dose-rate or pulse-dose-rate brachytherapy. Before brachytherapy, children had received chemotherapy with modalities depending on their risk group of treatment. Results A total of 100 patients were identified, with a median age of 28 months (range, 5.6 months-14 years). According to the Intergroup Rhabdomyosarcoma Study (IRS) group, 84 were IRS-III, and 12 were IRS-IV tumors. Four patients were treated at relapse. The median number of chemotherapy cycles before local therapy was 6 (range, 4-13). After surgery, 63 patients had a macroscopic tumor residuum. Five patients underwent a brachytherapy boost before pelvic external beam radiation therapy because of nodal involvement, and 95 had exclusive brachytherapy. Median follow-up was 64 months (range, 6 months-24.5 years). Five-year disease-free and overall survival rates were 84% (95% confidence interval 80%-88%) and 91% (95% confidence interval 87%-95%), respectively. At last follow-up most survivors presented with only mild to moderate genitourinary sequelae and a normal diurnal urinary continence. Five patients required a secondary total cystectomy: 3 for a nonfunctional bladder and 2 for relapse. Conclusion Brachytherapy is effective as part of a conservative strategy for BP RMS, with a relatively low delayed toxicity as compared with previously published studies using external beam radiation therapy. Longer follow-up is required to ensure that the functional results are maintained over time.