Relapse patterns after transoral laser microsurgery and postoperative irradiation for squamous cell carcinomas of the tonsil and tongue base.

OBJECTIVES: We evaluated relapse patterns after transoral laser microsurgery (TLM) in squamous cell carcinoma (SCC) of the tonsil and tongue base and evaluated the indications for adjuvant irradiation. METHODS: Between December 1, 1996, and December 31, 2005, 79 patients with previously untreated SCC of the tonsil or tongue base underwent TLM with or without neck dissection. Thirty-eight patients (48%) underwent postoperative irradiation (median, 62 Gy) to the primary site and the neck. Analysis of relapse patterns was performed on the basis of adverse risk factors and the presence or absence of adjuvant irradiation. RESULTS: The median follow-up for living patients was 47 months (range, 10 to 107 months), and patients were monitored for at least 2 years or until recurrence or death. Local, regional, and distant treatment failures numbered 4, 6, and 4 for surgery alone (n = 41) and 0, 2, and 6 for adjuvant irradiation (n = 38), respectively. Patients with high-risk features (extracapsular extension or at least 2 adverse factors) had locoregional control rates at 2 or more years of 66% and 94% for TLM alone and TLM plus adjuvant irradiation, respectively. CONCLUSIONS: Adjuvant irradiation after TLM resection of oropharyngeal SCC with intermediate- or high-risk features improves locoregional control compared with TLM alone.