To preserve the larynx in cases of T1b, T2 glottic cancer (squamous cell carcinoma), we have performed twice-a-day radiation therapy (60Co 1.2 Gy/fraction, over a-6-hour interval) for 3 T1b and 8 T2 patients between 1992 and 1994. The total dose administrated was 72-74.4 Gy. the preservation rates of the larynx were compared with those of a conventionally irradiated group (2 Gy/fraction, once-a-day, total dose 66 Gy) consisting of 24 T1b and 27 T2 patients treated between 1985 and 1994. The three-year preservation rates of the larynx in the conventionally treated group were 81% for T1b and 66.3% for T2 patients wile those in the twice-a-day group were 100% and 87.5% respectively. No major complications owing to the high total dose have been observed. Twice-a-day radiation therapy can thus be considered to be useful for preserving the larynx in the treatment of T1b, T2 glottic cancer.
