Results of fast neutron beam radiotherapy pilot studies at University of Washington

Thirty-seven patients received neutron beam radiotherapy for astrocytomas; thirty-six of these patients died. The mean survival was 10.8 and 7.5 months for patients with Grades III and IV lesions respectively. Autopsies of fifteen of these patients showed identifiable cancer in only one instance. One hundred and thirteen patients were treated for metastatic cervical adenopathy from squamous cell cancers of the head and neck. With a mean follow-up time of 14.5 months, 54% of the total group remained locally free of disease. Thirty-seven per cent of patients treated with neutrons only and 61% of patients treated with mixed beam irradiation maintained a complete remission at the sites of their adenopathy (p < 0.025). Fewer complications were seen in the mixed-beam irradiated group. One hundred and twenty-six were treated for primary squamous cell carcinomas of the head and neck region. With a mean follow-up time of 1.5 years, the local control rate was 51%. Twenty-eight per cent of those treated with neutrons alone and 63% of those treated with mixed beam were locally controlled. Mixed-beam therapy appears to be superior to neutrons only, both in terms of complication rates and local control of these tumors. (author)