Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed diagnosis of adenocarcinoma of the prostate within 180 days
of randomization

- History/physical examination with digital rectal examination of the prostate
within 60 days prior to registration

- Histological evaluation of prostate biopsy with assignment of a Gleason score to
the biopsy material; Gleason scores 2-6 within 180 days of randomization

- Clinical stage T1-2a (AJCC 7th edition) within 90 days of randomization

- Prostate-specific antigen (PSA) < 10 ng/mL within 60 days prior to registration;

- PSA should not be obtained within 10 days after prostate biopsy

- No evidence of distant metastases

- No regional lymph node involvement

PATIENT CHARACTERISTICS:

- Zubrod performance status 0-1

- Willingness and ability to complete the Expanded Prostate Cancer Index Composite
(EPIC) questionnaire

- No prior or concurrent invasive malignancy (except non-melanomatous skin cancer) or
lymphomatous/hematogenous malignancy unless continually disease-free for a minimum of
5 years (for example, carcinoma of the oral cavity is permissible; however, patients
with prior history of bladder cancer are not allowed)

- No severe, active co-morbidity, defined as follows:

- Unstable angina and/or congestive heart failure requiring hospitalization within
the last 6 months

- Transmural myocardial infarction within the last 6 months

- Acute bacterial or fungal infection requiring intravenous antibiotics at the
time of registration

- Chronic obstructive pulmonary disease exacerbation or other respiratory illness
requiring hospitalization or precluding study therapy at the time of
registration

- Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects

- Laboratory tests for liver function and coagulation parameters are not
required for entry into this protocol

- Acquired Immune Deficiency Syndrome (AIDS) based upon current Center for Disease
Control (CDC) definition

- HIV testing is not required for entry into this protocol

- Protocol-specific requirements may also exclude immuno-compromised patients

PRIOR CONCURRENT THERAPY:

- No prior radical surgery (prostatectomy), cryosurgery, or high-intensity focused
ultrasonography (HIFU) for prostate cancer

- No prior pelvic irradiation, prostate brachytherapy, or bilateral orchiectomy

- No prior hormonal therapy, such as luteinizing hormone-releasing hormone (LHRH)
agonists (e.g., goserelin, leuprolide) or LHRH antagonists (e.g., degarelix),
anti-androgens (e.g., flutamide, bicalutamide), estrogens (e.g., diethylstilbestrol
(DES)), or surgical castration (orchiectomy)

- No finasteride within 30 days prior to registration

- Prostate-specific antigen (PSA) should not be obtained prior to 30 days after
stopping finasteride

- No dutasteride within 90 days prior to registration

- PSA should not be obtained prior to 90 days after stopping dutasteride

- No prior or concurrent cytotoxic chemotherapy for prostate cancer

- Patients on Coumadin or other blood-thinning agents are eligible for this study

- No concurrent 3D-conformal radiation therapy