Prostate cancer is the most common malignant disease among men. Many young men are diagnosed with localized prostate cancer. Some of these men are choosing to manage their prostate cancer with radiation therapy. The radiation therapy delivers minimal dose exposure to adjacent organs. We hypothesize that when patients are treated with radiation therapy for localized prostate cancer, decreased fertility can occur due to damage of seminiferous tubules, which may affect sperm quality. This study will assess the impact of radiation therapy on semen and seminal fluid.