Study of Hypo-fractionated Proton Radiation for Low Risk Prostate Cancer

Inclusion Criteria:

Histologically confirmed prostate adenocarcinoma within 365 days prior to randomization.
History/physical examination with digital rectal examination of the prostate and baseline toxicity assessment within 90 days prior to randomization.
Histological evaluation of prostate biopsy with assignment of a Gleason score to the biopsy material;Gleason score must be in the range of 2-6. > 6 cores are strongly recommended.
PSA values < 10 ng/ml within 90 days prior to randomization. Either done prior to biopsy or at least 21 days after prostate biopsy.
Clinical stages T1a-T2a N0 M0 (AJCC Criteria 7th Ed.). Staging must be done by treating investigator.
No pelvic lymph nodes > 1.5 cm in greatest dimension unless the enlarged lymph node is biopsied and negative.
Patients must be at least 18 years old.
ECOG performance status 0-1 (appendix I) documented within 90 days prior to randomization.
IPSS score <= 16.
Patients must give IRB approved, study specific, informed consent.
Patients must complete all mandatory tests listed in section 4.0 within the specified time frames.
Patients must be able to start treatment within 56 days of randomization.

Exclusion Criteria:

Previous prostate cancer surgery to include: prostatectomy, hyperthermia and cryosurgery.
Previous pelvic radiation for prostate cancer.
Androgen deprivation therapy prior to radiation is allowed. However, it is not acceptable if continued during radiation or as adjuvant therapy.
Active rectal diverticulitis, Crohn's disease affecting the rectum, or ulcerative colitis.
Prior systemic chemotherapy for prostate cancer.
History of proximal urethral stricture requiring dilatation.
Current and continuing anticoagulation with warfarin sodium (Coumadin, heparin, low-molecular weight heparin, Clopidogrel bisulfate (Plavix),or equivalent. (Unless it can be stopped to manage treatment related toxicity, to have a biopsy if needed, or for marker placement).
Any major medical, addictive or psychiatric illnesses which would affect the consent process, completion of treatment and/or interfere with follow-up. Consent by legal authorized representative is not permitted in this study.
Evidence of any other cancer within the past 5 years and < 50% probability of a 5 year survival. (Prior or concurrent diagnosis of basal cell or non-invasive squamous cell cancer of the skin is allowed).