Inclusion Criteria:

- Biopsy confirmed adenocarcinoma of the prostate.

- T1-T2 disease based on digital rectal exam.

- T3a disease based on MRI only is acceptable.

- Gleason score 6-8.

- Patients with Gleason score 8 must be offered long term androgen deprivation therapy
(ADT) and refuse such treatment because only 6 months (short term ADT) is permitted
on this protocol. All Gleason score 8 patients must receive 6 months of ADT. The ADT
should begin after fiducial marker placement.

- Gleason 8 must have <20% of the tissue involved with Gleason 8 in the biopsy
specimen.

- Patients with Gleason score ≤7 may be treated with 4-6 months of ADT. The ADT
should begin after fiducial marker placement.

- Prostate-specific antigen (PSA) ≤20 ng/mL within 8 weeks of enrollment.

- No previous pelvic radiotherapy.

- No previous history of radical/total prostatectomy (suprapubic prostatectomy is
acceptable).

- No concurrent, active malignancy, other than nonmetastatic skin cancer or early stage
chronic lymphocytic leukemia (well-differentiated small cell lymphocytic lymphoma).
If a prior malignancy is in remission for > 5 years then the patient is eligible.

- Identifiable DCE-MRI tumor lesion or lesions, that total in volume <33% of the
prostate

- DCE-MRI of prostate and pelvis required prior to protocol consideration.

- Ability to understand and the willingness to sign a written informed consent
document.

- Zubrod performance status <2.

- Willingness to fill out quality of life forms.

- Bone scan negative if PSA >10 ng/mL or Gleason ≥7 disease. A questionable bone scan
is acceptable if plain x-rays and/or MRI are negative for metastasis.

- Serum testosterone is within 40% of normal assay limits and taken within 4 months of
enrollment.

- Serum liver function tests (LFT) are within 40% of normal assay limits and taken
within 8 weeks of enrollment.

- Complete blood counts are within 40% of normal assay limits, taken within 8 weeks of
enrollment.

- Age ≥35 and ≤85 years.

Exclusion Criteria:

- >T2 disease on digital rectal exam unless T3a disease is identified by MRI.

- Gleason score <6 and >8.

- ≥20% Gleason 8 tumor, over the total tissue including other tumor and normal tissue.
For example: (Gleason 8 tumor length/other biopsy tissue length)*100 = ≥20%.

- Patients are not eligible if they have been started on androgen deprivation therapy
prior to enrollment.

- Androgen deprivation therapy longer than 6 months. Androgen deprivation timing is for
the Luteinizing hormone-releasing hormone (LHRH) agonist portion only and not when
anti-androgen is started beforehand.

- PSA >20 ng/mL within 8 weeks of enrollment.

- Unable to obtain a 3T MRI of the pelvis and prostate with contrast prior to
randomization.

- Unidentifiable DCE-MRI tumor lesion.

- Identifiable DCE-MRI tumor lesions, that total in volume ≥33% of the prostate.

- Previous pelvic radiotherapy.

- Previous history of radical prostatectomy.

- Concurrent, active malignancy, which is not nonmetastatic skin cancer or early stage
chronic lymphocytic leukemia (well-differentiated small cell lymphocytic lymphoma).
If a prior malignancy is in remission for < 5 years then the patient is not eligible.

- Zubrod performance status ≥ 2.

- Inability to understand or unwilling to sign a written informed consent document

- Unwilling to fill out quality of life/psychosocial forms.

- Bone scan is positive if PSA >10 ng/mL or Gleason ≥7 disease.

- Serum testosterone is not within 40% of normal assay limits taken within 4 months of
enrollment.

- Serum liver function tests (LFTs) are not within 40% of normal assay limits taken
within 8 weeks of enrollment.

- Complete blood counts are not within 40% of normal assay limits taken within 8 weeks
of enrollment.

- Age <35 and >85 years.