Advantage of Accelerated Fractionation Regimens in Definitive Radiotherapy for Stage II Glottic Carcinoma

Abstract

Objectives: We evaluated the prognostic factors for local control of T2 glottic cancer and verified the efficacy of accelerated fractionation regimens such as hyperfractionation and accelerated hyperfractionation. Methods: A total of 86 patients with T2 NO MO glottic squamous cell carcinoma, who were treated with definitive radiotherapy, were analyzed retrospectively by multivariate analysis. Results: Overall treatment time of radiotherapy (p = .0003) and total dose (p = .0036) were the significant prognostic factors for local control on multivariate analysis. The group with a higher total dose (>67 Gy versus <67 Gy) showed a favorable prognosis (5-year local control rate of 91% versus 60%, respectively; p = .0013, log-rank test). Likewise, the group with a shorter overall treatment time of radiotherapy (<54 days versus >54 days) showed a favorable prognosis (5- year local control rate of 87% versus 71%, respectively; p = .023). Conclusions: A radiotherapy total dose of >67 Gy delivered for a shorter period is required for T2 glottic cancer. The fractionation regimens of hyperfractionation and accelerated hyperfractionation are more effective than conventional fractionation in terms of shortening overall treatment time and delivering a high total dose with acceptable toxicity.