Accelerated superfractionated irradiation for advanced carcinoma of the head and neck: concomitant boost technique

Between 1980 and 1988, 94 patients with AJCC Stage III and IV squamous cell carcinoma of all sites of the upper aero-digestive tract were treated with radiotherapy. We report here on 62 patients who are followed for a minimum of 2 years. Of these, 30 patients were treated with conventional once-a-day radiotherapy and 32 patients were irradiated using an accelerated superfractionation regimen during part of the treatment course. The altered fractionation schedule employed a concomitant boost technique with clinically demonstrable disease being irradiated twice-a-day during the first or second half of the treatment course. Daily radiation fractions were 1.8 Gy and the boost field was treated with 1.6 Gy after a 4- to 6-hr interval. No significant differences in acute treatment toxicity were observed in the two treatment groups. Patients treated with conventional and accelerated fractionation regimens experienced 36 months actuarial local tumor control rates of 40% and 67% (p = 0.03), respectively, which translated into an actuarial disease-free survival of 40% and 64% (p = 0.04). The increased locoregional control rates in patients treated with accelerated fractionation were associated with an adjusted and overall survival advantage at the p = 0.05 level. We conclude that our regimen of accelerated superfractionated irradiation with shortening of the treatment course resulted in improved control and survival rates at conventional doses of 68.4 to 73.8 Gy.