Inclusion Criteria:

- Histologically proven diagnosis of prostate adenocarcinoma within one year

- Gleason Score 2-7

- Clinical T-stage T1b-T2c (AJCC 7th Edition)

- Clinical Nx or N0, and Mx or M0

- PSA < 20 ng/mL

- Low or intermediate risk according to NCCN guidelines: Low: Clinical Stage (CS)
T1b-T2a and Gleason 2-6 and PSA < 10 ng/ml; Intermediate: CS T2b-T2c and Gleason 2-6
and PSA < 10 ng/ml, or CS T1b-T2a and Gleason 7 and PSA < 10 ng/ml, or CS T1b-T2a and
Gleason 2-6 and PSA 10-20ng/mL

- ECOG performance status 0 or 1

- Has had a pre-treatment PSA drawn within a month of the beginning of protocol therapy

- If androgen-deprivation therapy (ADT) has been initiated, must have a documented
pre-ADT PSA; this baseline PSA should not be obtained during following periods: 1)
10-day period following prostate biopsy; 2) within 30 days after discontinuation of
finasteride; or 3) within 90 days after discontinuation of dutasteride.

- Has completed a baseline health-related quality of life assessment Extended Prostate
Cancer Index Composite questionnaire (EPIC-26)

- Has had a history and physical examination (including digital rectal examination and
a formal morbidity assessment via the ACE-27) within 60 days

- Morbidity score (via the ACE-27) of none (0), mild (1) or moderate (2)

- Willing and able to use adequate contraception during protocol treatment and for 3
months after the completion of protocol treatment

Exclusion Criteria:

- Invasive (carcinoma in situ is allowed) solid or hematologic malignancy (other than
this prostate cancer, or basal or squamous skin cancers) in the last 5 years

- Prior prostatectomy or cryotherapy of the prostate

- Prior radiotherapy to the prostate or lower pelvis

- Prior or concurrent cytotoxic chemotherapy for prostate cancer (prior chemotherapy
for a different cancer is allowed)

- Implanted hardware near the planning target volume that would prohibit appropriate
treatment planning or treatment delivery in the investigator's opinion