Long-term outcomes with high-dose-rate brachytherapy for the management of base of tongue cancer

Abstract

To report the long-term results of a prospective, nonrandomized clinical trial using high-dose-rate (HDR) brachytherapy (BT) for the management of base of the tongue (BOT) tumors. Between January 1992 and June 2011, 60 patients (mean age, 57 years; range, 36-78 years) with T1-T4 and N0-3 carcinoma of BOT were treated. Fifty-six patients (93%) had advanced (Stage III-IV) disease. HDR BT boost (mean dose, 17Gy; range, 12-30Gy) was delivered after 50-70Gy (mean 62Gy) locoregional external beam irradiation. Seventeen patients (28%) received radiochemotherapy (RCT) with cisplatin. The 5-year actuarial rate of local tumor control, locoregional tumor control, overall survival (OS), and cancer-specific survival (CSS) was 57%, 50%, 47%, and 61%, respectively. OS was significantly better in patients (n=17) receiving RCT (69% vs. 39%; p=0.005). Delayed soft-tissue ulceration occurred in seven patients (12%). Only one patient (<2%) developed osteoradionecrosis. In univariate analysis, the tumor size (T1-T2-T3 vs. T4) was found to have a significant effect on CSS (p=0.043), whereas the nodal status (N0 vs. N+) affected locoregional tumor control (p=0.042), OS (p=0.002), and CSS (p=0.015). Low histologic grade (1-2) was associated with better CSS (p=0.020), whereas RCT significantly improved OS (p=0.012). External beam irradiation combined with interstitial HDR BT boost results in good local tumor control with an acceptable rate of late side effects in patients with BOT carcinoma. RCT improves OS. Our results are similar to those reported with traditional low-dose-rate BT implants.