The results of radiation therapy for glottic carcinoma: Prognostic significance of tumor size in laryngoscopic findings

Seventy-five patients with carcinoma of the true vocal cord were treated wi th curative intent by radiotherapy at Kure National Hospital between 1977 a nd 1997. All tumors were classified according to stage (T1, T2 and T3), deg ree of differentiation (well-differentiated, moderately differentiated, poo rly differentiated and unknown), and size (very small, small and large). Al l patients were treated using a cobalt-60 unit to a total dose that ranged from 56 Gy to 64 Gy (mean, 60 Gy). The mean treatment time was 44 days (ran ge, 38-50 days). The local control and ultimate local control rates at 5 ye ars were 75.8% and 91.4% for all patients, respectively. Univariate analysi s showed that tumor size (p=0.0350) and stage T (p=0.0416) affected local c ontrol. In multivariate analysis, tumor size was the only significant facto r that affected local control (p=0.0012). The most significant factor that affected local control was tumor size in laryngoscopic findings. Tumor size was inversely related to local control.