Fast neutron therapy for prostatic cancer

Twenty-six patients with prostatic cancer were treated by fast neutron therapy and clinical effect was observed. Twenty three patients did not receive any previous treatment for prostatic cancer (stage A 2, B 3, C 14, D 4) and the other three patients were refratory to the endocine therapy. 1. Early effect (within 6 months after fast neutron therapy; 1 local control, 24/26 (92%), 2 improvement of dysuria, 8/8 (100%), 3 reduction of elevated serum acid phospatase, 7/8 (88%). 2. Late effect ; 7 patients died within 3 years. Relatively ineffectiveness on these 7 cases might be due to rather limited field of radiation (6/7, 86%), lower time dose and fractionation (TDF100, 6/7, 86%) and poorly differentiated adenocarcinoma (6/7, 86%). Actual 3-year survival rate was 77.2% for stage C, 53. 9% for D. This result showed that it was necessary to extend radiation field, increase TDF and combine endocrine or chemotherapy for poorly diff. type. (author)