Stereotactic Body Radiation Therapy in Treating Patients With Low- and Intermediate-Risk Prostate Cancer

PRIMARY OBJECTIVES:

I. To evaluate, in terms of late toxicity, the safety of stereotactic radiation therapy using
the proposed fractionation schedule.

SECONDARY OBJECTIVES:

I. To evaluate, in terms of acute toxicity, the safety of stereotactic radiation therapy
using the proposed fractionation schedule.

II. To determine stereotactic treatment efficacy through biochemical failure (Phoenix
criteria).

III. To determine the protocol completion rate. IV. To describe patient-reported outcomes
using International Index of Erectile Function (IIEF) and EPIC Urinary and Bowel Assessment
questionnaires.

OUTLINE: Patients are randomized to 1 of 2 treatment arms.

ARM I: Patients undergo standard daily fractions of stereotactic body radiation therapy
(SBRT) over 7-8.5 weeks.

Inclusion Criteria:

- Patients must have low or intermediate risk adenocarcinoma of the prostate as defined
by:

- Low-risk disease - Histopathology score (Gleason sum): =<6, T-stage (per current
AJCC staging criteria): T1c-T2a, and PSA: <10

- Intermediate-risk disease as either:

- Histopathology score (Gleason sum) =< 6, T-stage (per current American Joint
Committee on Cancer [AJCC] staging criteria): T1c-T2a, and prostate-specific
antigen (PSA) > 10 but =< 20; or

- Histopathology score (Gleason sum) 7 with =< 50% of any cores positive,
T-stage (per current AJCC staging criteria): T1c-T2a, and PSA < 10

- Charlson index of comorbidity score =< 4

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

Exclusion Criteria:

- Patients with history of inflammatory bowel disease, or who require steroid or
cytotoxic therapy for collagen vascular disease

- Patients with a history of cancer other than skin cancer within 5 years of the
initiation of protocol treatment

- Patients with a history of pelvic irradiation for any reason

- Life expectancy < 10 years - Prior treatment with an anti-androgen, luteinizing
hormone-releasing hormone (LHRH) agonist, or a combination of the two

- Prior radiation therapy, brachytherapy, or cryotherapy

- Prior surgical procedure involving peri-rectal and peri-prostatic area