Radiation therapy for advanced head and neck squamous cell carcinoma using twice-a-day fractionation. A long-term follow-up.

Twenty-one patients with massive advanced squamous cell carcinoma of the head and neck received radiation therapy under the twice-a-day fractionation regimen. One hundred ten rad tumor dose was delivered twice daily with a 4-hour gap between the fractions, 5 days/week, to a total tumor dose of 7480 rad. The purpose was to increase the therapeutic ratio by minimizing sublethal radiation damage to normal tissue while allowing reoxygenation of radioresistant hypoxic tumor cells. Fifty-three percent of the patients showed no evidence of primary tumor at the end of the therapy and 60% showed complete regression of massive cervical lymphadenopathy. The 2-year recurrent-free rates for patients with tumors of the tonsillar region were 36% of T4 (4/11) and 33% (2/6) of N3a. The experience with conventional fractionation in similar cases was previously reported by others from this institution. They reported 2-year recurrent-free rates of 0% of T4 (0/10) and 17% (1/6) of N3. The higher recurrent-free rates in our series suggests better local and regional tumor control by the twice-a-day fractionation.