The importance of hypoxia in prostate cancer has not previously been evaluated. The aims of this study are to determine how often hypoxia occurs in early prostate cancer and whether hypoxia influences the success of RT, tumor spread beyond the prostate to bones and other organs and the development of hormone-resistant disease. Patients will have tumor oxygen levels measured using a special fine-needle electrode system prior to beginning treatment with either RT or the combination of hormones plus RT. The measurements will be made through the rectum using ultrasound to position and guide the electrode. A biopsy of the tumor will be obtained at the site of the measurements, and this will be used to determine how oxygen influences changes in the genetic character of prostate cancer cells. A total of 195 patients will be evaluated in this way over 3 years.