Radiotherapy for glottic T1N0 carcinoma with slight hypofractionation and standard overall treatment time: Importance of overall treatment time

Abstract

Objective: We retrospectively investigated treatment outcomes in patients with glottic T1 carcinoma treated with 65 Gy in 26 fractions four times a week and discuss the importance of the overall treatment time. Methods: Two hundred one patients with glottic T1 carcinoma were evaluated. Sixty-five Gray in 26 fractions were delivered for 200 patients, whereas 1 patient received 62.5 Gy in 25 fractions. We delivered radiotherapy once daily four times a week in this period, for a weekly dose of 10 Gy. Weekdays except Wednesday were treatment days. Results: The overall survival rate was 96.8±1.3% (standard error) at 3 years and 90.8± 2.2% at 5 years. The local control rate was 91.9±2.0% at 3 years and 89.8±2.3% at 5 years. In patients with an overall treatment time equal to or longer than 47 days, the local control rate was 82.6±6.0% at both 3 and 5 years. In the patients with overall treatment time equal to or less than 46 days, the local control rate was 94.6±1.9% at 3 years and 91.8± 2.4% at 5 years. There was a significant difference between these two groups (P = 0.0349). A severe late radiation reaction occurred in one patient. He experienced severe laryngeal edema that required tracheotomy at 6 months after the completion of radiotherapy. The tracheotomy was closed at 14 months after completion of radiotherapy. Conclusions: Overall treatment time seems to be an important factor for a good local control rate for glottic T1N0 carcinoma even when treated with slight hypofractionation. © The Author (2010). Published by Oxford University Press. All rights reserved.