Optimized radiotherapy treatment strategy for early glottic carcinoma.

The local control rates of T1 bulky and T2 glottic carcinoma treated via radiation therapy alone are unsatisfactory; thus, we aimed to evaluate the efficacy and safety of our treatment protocol for early glottic carcinoma. Patients with early glottic squamous cell carcinoma treated via radiation therapy from January 2007 to November 2019 were reviewed. Patients were treated with: 63-67.5 Gy/28-30 fractions of radiation therapy alone for T1 non-bulky; concurrent chemoradiotherapy with S-1 and 60 Gy/30 fractions for T1 bulky and T2 favorable; and concurrent chemoradiotherapy with high-dose cisplatin and 66-70 Gy/33-35 fractions for T2 unfavorable glottic carcinoma. Local failure rates were estimated using the cumulative incidence function, overall and disease specific survival rates were estimated using Kaplan-Meier analysis, and adverse events were evaluated. Eighty patients were analyzed; the median age was 69.5 (range, 26-90) years, the median follow-up time for survivors was 40.1 (range, 1.9-128.4) months, and the 3-year local failure, disease specific survival, and overall survival rates were 5.8%, 98.3%, and 94.4%, respectively. In T1 bulky and T2 cases, the local failure rate was significantly lower in the concurrent chemoradiotherapy than in the radiation therapy alone group. Grade 3 acute dermatitis and mucositis were noted in nine and four patients, respectively. There were no acute adverse events of Grade 4 or higher, or late adverse events of Grade 2 or higher. The treatment protocol was effective and well-tolerated; thus, the efficacy of concurrent chemoradiotherapy was suggested in T1 bulky and T2 cases.