Twice-a-day radiation therapy for supraglottic carcinoma

This is a report of a group of 106 patients with supraglottic carcinomas treated by the twice-a-day radiation therapy program at the Massachusetts General Hospital from October 1979 through April 1984. The program consisted of 1.6 Gy per fraction, 2 fractions a day, 5 days a week for a total of 64 Gy with 2 weeks rest after the twelfth b.i.d. day. The local control of this group of patients was compared to that of 79 patients treated by the conventional once-a-day program with a daily fraction of 1.8 Gy for a total of 65 Gy, at the same institution during the 4 years immediately prior to the b.i.d. program. The 3 year actuarial local control rate for the entire group following the twice-a-day program was 76% as compared to 50% after the once-a-day program. The difference was significant, p = 0.001. For the T1 and T2 lesions, the corresponding rates were 88 and 63%, respectively, with a p value of 0.029. The rates for T3 and T4 lesions were 66 and 33%, respectively, p = 0.0037. The study indicated that the twice-a-day radiation therapy program as outlined is effective in treatment of supraglottic carcinoma, and is more markedly effective in advanced lesions. Late radiation effects are minimal and salvage surgery is possible for radiation therapy failures. To date, no patient developed radiation myelitis following the b.i.d. program with the dose to the spinal cord limited to 38.4 Gy in 2.5 weeks.