Phase III Study of Mildly Hypo-fractionated Image Guided Proton Beam Radiation Therapy With or Without Androgen Suppression for Intermediate Risk Adenocarcinoma of the Prostate

Inclusion Criteria:

- Histologically confirmed prostate adenocarcinoma (within 365 days of randomization)
at intermediate risk for reoccurrence determined by at least one of the following:
Gleason Score 7, PSA > = 10 and < = 20, T stage T2b - T2c

- Clinical stages T1-T2c N0 M0 as staged by the treating investigator. (AJCC Criteria
7th Ed.- appendix III).

- Histological evaluation of prostate biopsy with assignment of a Gleason score to the
biopsy material; Gleason score must be in the range of 2-7. > 6 cores are strongly
recommended.

- PSA values < = 20 ng/ml within 90 days prior to randomization. Obtained prior to
biopsy or at least 21 days after prostate biopsy.

- ECOG performance status 0-1 (appendix II) assessed within 90 days of randomization.

- Patients must sign IRB approved study specific informed consent.

- Patients must complete all required pre-entry tests listed in section 4.0 within the
specified time frames.

- Patients must be able to start treatment within 56 days of randomization.

- Patients must be at least 18 years old.

- IPSS ≤ 16.

Exclusion Criteria:

- Pelvic lymph nodes > 1.5 cm in greatest dimension unless the enlarged lymph node is
biopsied and negative.

- Previous prostate cancer surgery to include: prostatectomy, hyperthermia and
cryosurgery.

- Previous pelvic radiation for prostate cancer.

- Previous androgen suppression therapy for prostate cancer.

- Active rectal diverticulitis, Crohn's disease affecting the rectum or ulcerative
colitis (non-active diverticulitis and Crohn's disease not affecting the rectum are
allowed).

- 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 or to have a biopsy if needed).

- Major medical, addictive or psychiatric illness which in the investigator's opinion,
will prevent the consent process, completion of the treatment and/or interfere with
follow-up. (Consent by legal authorized representative is not permitted for 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).

- History of myocardial infarction within the last 6 months.