Treatment outcomes of external-beam radiotherapy for squamous cell carcinoma of the base of the tongue.

Purpose: To evaluate definitive external-beam radiotherapy (EBRT) for patients with base of the tongue (BOT) cancers. Methods: We reviewed results for 26 patients with BOT cancers who were treated with EBRT. Clinical stages T1, T2, T3, and T4a were observed for 10, 7, 4, and 5 patients, respectively, and stages N0, N1, N2a, N2b, N2c, and N3 were observed for 4, 2, 5, 6, 8, and 1 patients, respectively. More than half of the patients ( n = 19) were stage IVA. Standard total delivered doses were 70 Gy to primary tumors and cervical lymph node (CLN) metastases and 40-46 Gy to elective nodal regions. Eleven patients with advanced loco-regional disease received concurrent or neoadjuvant chemotherapy. Four T3 patients and one T2 patient received 2 or 3 cycles of concurrent intra-arterial cisplatin with EBRT (RADPLAT). Results: Three-year overall survival was 69 % (95 % CI 47-83 %), with a median follow-up period of 33 months. Three-year local control was 100, 86, 100, and 20 % for T1, T2, T3, and T4 patients, respectively. Three-year regional control was 100 % for N0, N1, and N2a, 83 % for N2b, 75 % for N2c, and 0 % for N3 patients. Treatment failed for 7 patients. All 5 patients undergoing RADPLAT achieved complete responses and did not develop local recurrence. Conclusions: We achieved favorable outcomes for patients with T1-T3 BOT cancers by use of definitive EBRT with or without chemotherapy. [ABSTRACT FROM AUTHOR]