Long-term outcome of high-dose-rate brachytherapy and perioperative brachytherapy in early mobile tongue cancer

Purpose
To evaluate long-term outcome of high-dose-rate brachytherapy and perioperative brachytherapy in early mobile tongue cancer.

Material and methods
Seventy-three patients with clinically staged T1/T2 N0 M0 of mobile tongue cancer were studied retrospectively. Between January 2000 and September 2010, 47 patients underwent high-dose-rate brachytherapy (HDR-BT) alone and 26 patients underwent perioperative brachytherapy (PB). Endpoints were overall survival, disease-free survival, loco-regional control, and late side effects.

Results
Median age was 52 years and median follow-up was 74 months (range, 60-180). There were no local recurrences in the PB group. Overall survival at 6 years was 74.7% vs. 92.3% in HBR BT and PB group, respectively (p = 0.032). Disease-free survival at 6 years was 55.3% vs. 92.3% respectively in HDR-BT and PB (p = 0.002). Disease-free survival at 6 years in tumor histologic grade 1/2 patients was 76.3 months versus 40% in grade 3 patients. Nodal recurrence-free rate at 6 years was 67.5% with HDR-BT only, and 96.2% with PB (p = 0.007). In HDR BT only group, nodal recurrence-free rate at 6 years in T1 patients was 89.8% versus 29.4% in T2 patients. 16% and 7% patients developed soft tissue necrosis and osteoradionecrosis, respectively. Multivariate Cox proportional hazards analysis revealed significant correlation of local recurrence with tumor grade (p = 0.029), nodal recurrence with T-stage (p = 0.007), and disease-free survival with age (p = 0.003) and T stage (p = 0.026).

Conclusions
HDR-BT alone gives acceptable loco-regional control in T1 tumors. T2 stage tumors should not be treated by brachytherapy alone in view of high failure rates in nodal regions and should undergo either neck dissection or nodal irradiation. Perioperative brachytherapy is investigational and can be considered in patients who are at high-risk for local recurrence in patients undergoing surgery alone.