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 with curative intent by radiotherapy at Kure National Hospital between 1977 and 1997. All tumors were classified according to stage (T1, T2 and T3), degree of differentiation (well-differentiated, moderately differentiated, poorly differentiated and unknown), and size (very small, small and large). All 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 (range, 38-50 days). The local control and ultimate local control rates at 5 years were 75.8% and 91.4% for all patients, respectively. Univariate analysis showed that tumor size (p=0.0350) and stage T (p=0.0416) affected local control. In multivariate analysis, tumor size was the only significant factor 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.