Neutron therapy for head and neck cancer: II. Further follow-up on the M. D. Anderson TAMVEC randomized clinical trial.

Between January 1977 and February 1980, 95 patients with inoperable squamous carcinomas of the head and neck were treated in a two-armed randomized clinical trial comparing 1) mixed schedule irradiation using two neutron and three photon fractions per week and 2) standard photon irradiation. Complete tumor regression was achieved in 80% of patients treated with mixed-schedule irradiation, and in 68% of patients treated with photons. The local control rate was 44% in patients treated with mixed-schedule irradiation and 41% in patients treated with photons. There were four complications of treatment in each treatment arm. Absolute survival was 20% with mixed-schedule treatment and 17% in photons. Actuarial analysis shows superior local control and survival rates with mixed-schedule irradiation over photons only in the first two years.