FAST-NEUTRON THERAPY IN ADVANCED HEAD AND NECK-CANCER - A COLLABORATIVE INTERNATIONAL RANDOMIZED TRIAL

Purpose: To compare the efficacy of fast-neutron radiotherapy with tha t of conventionally fractionated photon therapy in the management of p atients with locally advanced squamous cell carcinoma of the head and neck. Methods and Materials: Patients with Stage III or IV disease wer e randomized to receive either 20.4 Gy/12 fractions/4 weeks of neutron s or 70 Gy/35 fractions/7 weeks of photons (control). Between April 19 86 and March 1991, 178 patients were entered, 169 of whom were eligibl e for analysis. The treatment arms were balanced for age, stage, and p erformance status, but not for primary site of origin. Results: Comple te response occurred in 70 and 52% with neutrons and photons, respecti vely (p = 0.006). Local regional failure at 3 years for all patients w as 63% for neutrons and 68% for photons. Actuarial overall survival cu rves were virtually identical in both study arms, falling to 27% at 3 years. Acute toxicity was similar in the two arms, but late grade 3-5 toxicity was 40% with neutrons compared to 18% with photons (p = 0.008 ). Conclusion: Although the initial response rate was higher with neut rons, permanent local control and survival were not improved, and the incidence of late normal tissue toxicity was increased. As a result, f ast-neutron therapy for advanced squamous cell carcinoma of the head a nd neck can only be recommended for patients in whom the logistic bene fit of treatment in 12 sessions over 4 weeks outweighs the increased r isk of late toxicity.