Prospective Evaluation of Stereotactic Body Radiotherapy for Metastatic Prostate Cancer

The investigators and other investigators have previously documented the safety and efficacy
of definitive intent stereotactic body radiotherapy (SBRT) in the treatment of localized
prostate cancer.

In the metastatic setting for multiple malignancies, improved survival rates and disease
outcomes have been shown with definitive treatment of the primary disease site. This concept
of "cytoreductive" surgery or decreasing the primary tumor burden is now considered the
standard of care for metastatic colon, ovarian, renal cell, and some breast carcinomas (plus
post-surgery irradiation).

With new guidelines and declining rates of PSA screening, the incidence of newly diagnosed
metastatic prostate cancer is expected to increase. A recent population-based study has
concluded significant improvements in the definitive treatment of the local prostate cancer
in the stage IV setting with either radical prostatectomy or conventional prostate radiation
treatments/brachytherapy. To our knowledge, one prospective phase II trial is currently
accruing patients to best systemic therapy or best systemic therapy (BST) plus definitive
treatment with either radical prostatectomy or conventionally fractionated radiation therapy

The investigators hypothesize that the addition of primary disease SBRT to best systemic
therapy for newly diagnosed metastatic prostate cancer would be associated with an acceptable
safety profile, quality of life, disease progression, and overall survival. The addition of
SBRT to best systemic therapy is also expected to be better-received for stage IV patients
(with relatively limited prognosis), vs. fully fractionated radiation therapy, brachytherapy,
or radical prostatectomy. The above endpoints would initially be tested in a prospective
phase II multi-institutional trial and in comparison with historical controls.

Inclusion Criteria:

- Histologically-confirmed, adenocarcinoma of the prostate

- Clinical Stage T1b - T4, NX-0-1, M1

- Any Gleason score

- PSA<1000

- ECOG Performance Status 0-2

- No prior prostate radiation or other definitive therapy

Exclusion Criteria:

- Prior prostatectomy or cryotherapy of the prostate

- Prior radiotherapy to the prostate or lower pelvis

- Implanted hardware or other material that would prohibit appropriate treatment
planning or treatment delivery, in the investigator's opinion

- Chemotherapy for a malignancy in the last 5 years

- History of an invasive malignancy (other than this prostate cancer, or basal or
squamous skin cancers) in the last 5 years