A randomized Phase III study was started in Japan to demonstrate the non-inferiority of survival of accelerated fractionation radiation therapy (2.4 Gy/fr) with conventional fractionation radiation therapy (2 Gy/fr) in patients with T1-2N0M0 glottic cancer. This study began in September 2007, and a total of 360 patients will be accrued from 22 institutions within 4 years. The primary endpoint is 3-year progression-free survival (PFS). The secondary endpoints are overall survival, local progression-free survival, disease-free survival, survival with preserved voice function, complete response rate, proportion of treatment completion and adverse events.