Degarelix Acetate Before and During Radiation Therapy in Treating Patients With Prostate Cancer

Inclusion Criteria: * Willing and able to provide written informed consent * Written authorization for use and release of health and research study information has been obtained * Histologically proven adenocarcinoma of the prostate * Patients must be candidates for short or long term androgen deprivation in combination with external beam radiation therapy (RT) based on the following criteria: * Intermediate risk disease: T2b/c, or Gleason 7, or prostate-specific antigen (PSA) 10-20 * High risk disease: Gleason 8-10, or PSA \> 20, or T3/4 * Patients may not have received any prior pharmacologic therapy or RT for prostate cancer * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 (Karnofsky \>= 60%) * Eligibility of patients receiving any medications or substances known to affect or with the potential to affect the androgen axis will be determined following review of their case by the principal investigator * Patients must allow biopsy at the time of fiducial placement Exclusion Criteria: * Patients may not be receiving any investigational agents * Patients who are currently receiving active therapy for other neoplastic disorders will not be eligible * Patients with histologic evidence of small cell carcinoma of the prostate will not be eligible * Patients with hypogonadism or severe androgen deficiency as defined by serum testosterone less than 100 ng/dL will not be eligible * History of pituitary dysfunction * Patients who are receiving any androgens, estrogens or progestational agents, or who received any of these agents within the 6 months prior to evaluation will not be eligible * Patients who are taking drugs which affect androgen metabolism (e.g. spironolactone, ketoconazole, finasteride, dutasteride) will not be eligible; patients who received any of these agents within the 6 months prior to evaluation will be reviewed for eligibility by the principal investigator on a case by case basis * Patients with inflammatory bowel disease or other autoimmune conditions which might affect the radiated colon or rectum * Patients with uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, unstable angina pectoris, cardiac arrhythmia which is symptomatic or requires active therapy, recent deep venous thrombosis, pulmonary emboli, cerebrovascular accident or ischemia will not be eligible * Patients with dementia/psychiatric illness/social situations that would limit compliance with study requirements or would prohibit the understanding and/or giving of informed consent will not be eligible * Patients with medical conditions, which, in the opinion of the investigators, would jeopardize either the patient or the integrity of the data obtained will not be eligible * Other active malignancy, except non-melanoma skin cancer and superficial bladder cancer * Patients unwilling to use contraceptives while on study