PRIMARY OBJECTIVE:

      I. To determine if stereotactic body radiation therapy (SBRT) would result in similar freedom
      from failure (FFF) than standard fractionation photon therapy.

      EXPLORATORY OBJECTIVES:

      I. After completion of radiation therapy, determine the incidence of grade 2 or greater
      genitourinary (GU) and gastrointestinal (GI) toxicity at 6 months (Common Terminology
      Criteria for Adverse Events [CTCAE] version 4).

      II. After completion of radiation therapy, determine the incidence of grade 3 or greater GU
      and GI toxicity at 6 months (CTCAE version 4).

      III. After completion of radiation therapy, determine the incidence of quality of life issues
      following completion of radiation therapy.

      IV. After completion of radiation therapy, determine the incidence of impotence after the use
      of radiation therapy at 3 years.

      V. After completion of radiation therapy, determine the incidence of freedom from biochemical
      failure (FFBF) at 5 years.

      VI. After completion of radiation therapy, determine the incidence of clinical failure: local
      and/or distant at 5 years.

      VII. After completion of radiation therapy, determine the incidence of salvage androgen
      deprivation use (SAD) at 5 years.

      VIII. After completion of radiation therapy, determine the incidence of progression free
      survival: using clinical, biochemical and SAD as events at 5 years.

      IX. After completion of radiation therapy, determine the incidence of overall survival at 5
      years.

      X. After completion of radiation therapy, determine the incidence of disease-specific
      survival at 5 years.

      XI. Determine the impact of radiation therapy on quality of life. XII. Determine overall GI
      and GU toxicity. XIII. Determine prostate and normal structure movement during radiation
      therapy (RT) with the use of scans.

      XIV. Correlate pathologic and radiologic findings with outcomes. XV. Correlate pre-RT
      prostate specific antigen (PSA) levels with outcomes. XVI. Correlate variation in proton
      therapy or x-ray dosimetry and outcomes. XVII. Develop a quality assurance process for
      prostate proton therapy. XVIII. Prospectively collect information that will help to define
      dose-volume relationships of normal structures with acute and chronic toxicity.

      XIX. Allow for future research of pathologic risk factors that may influence prognosis; this
      information will help us to attempt to characterize their presence in prostate cancer with
      high risk features after prostatectomy and their potential effect on outcomes.

      XX. Possibly compare dosimetric parameters of an IMRT plan with the proton therapy radiation
      plan.

      OUTLINE: Participants are assigned to 1 of 3 groups.

      GROUP I: Participants undergo hypofractionated radiation therapy over 15-30 minutes every
      other day over 2 weeks, for 5 treatments.

      GROUP II: Beginning 8-10 weeks before radiation therapy, participants receive androgen
      suppression therapy subcutaneously (SC) or intramuscularly (IM) for up to 6 months (at the
      discretion of the treating physician). Participants then undergo hypofractionated radiation
      therapy as Group I.

      GROUP III: Participants receive androgen suppression therapy as Group II for up to 18 months
      (at the discretion of the treating physician), then undergo hypofractionated radiation
      therapy over 15-30 minutes every other day over 1-2 weeks, for 1-5 treatments.

      After completion of study treatment, participants are followed up at 3 and 12 months,
      annually for 4 years, then every 2 years thereafter.