The overall objective of the study is to continue a major research program for clinical trials in fast neutron therapy in order to evaluate the effectiveness of neutron therapy relative to other forms of conventional radiation therapy. Since all essential preclinical physical measurements and calibration, radiobiological studies, and pilot studies on patients referred with locally advanced disease have been completed satisfactorily, our objective at this stage is a strictly controlled experiment within a cooperative national protocol to evaluate one modality against another in randomly selected groups of patients. This work will concentrate mainly on subjects eligible for entry into the RTOG protocols: Resectable and Nonresectable Late Stage Cancer of the Head and Neck, Malignant Brain Tumors, Cancer of the Prostate and Bladder, Late Stage Carcinoma of the Cervix, Carcinoma of the Esophagus, Small Cell Carcinoma of the Lung, Carcinoma of the Pancreas, Tumors of Salivary Glands, Radioresistant Adenocarcinomas, Bone and Soft Tissue Sarcomas.