The clinical activities of this program will be expanded further with the addition of another physician and of technical support personnel. Specific attention will be directed to treatment of patients with carcinoma of oral cavity and oro-pharynx (4 patients with floor of mouth cancers have been treated). We will initiate a prospective randomized trial of photons plus perineal boost proton vs photon alone in the treatment of prostate cancer. Also the trial of 7000 vs 9000 rads (in 5 fractions over 7-9 days) as the definitive treatment of choroid melanoma will be continued. Further, we expect to initiate a study of proton therapy of the para-aortic node region. With respect to technical ability our intent is to install the therapy modified EMI 7070 CBT unit and prepare programs for the use of the VAX computer (permitting almost immediate CBT scans in any plane in the section of the body under study). Radiobiological studies will be expanded to: 1) Evaluate efficacy of radio-protective compounds applied topically to the skin and 2) assess the relationship between treatment volume and tolerance.