Stereotactic Body Radiation Therapy (SBRT) for Prostate Cancer

External beam radiation therapy for prostate cancer, while effective, takes up to 9 weeks to
deliver on a Monday through Friday basis. Recent phase I/II studies from Seattle and Palo
Alto using stereotactic guidance to deliver high doses of radiation to the prostate over a 1
to 2 week period of time suggest that outcomes may be equal or superior to standard
approaches. These data, combined with markedly improved convenience for patients, make
radiosurgery (SBRT) for early-stage prostate cancer an enticing option. The goal of this
study is to offer a radiosurgical option to patients within the Sharp system under the
umbrella of an IRB-approved study.

Inclusion Criteria:

- Male with any age (typically 50 to 70 years old) with a low risk disease. This is
defined as a Gleason's score of 6 or less, clinical stage of T2a or less, and a PSA
of less than 15. We will also include patients with Gleason's score of 3+4=7 if there
are fewer than 2 cores positive, with no more than 5mm of tumor in aggregate
dimension.

Exclusion Criteria:

- Prior surgery or radiotherapy for prostate cancer, PSA over 10, Gleason scores 7, 8,
9, or 10 (except Gleason 7 as noted, above), or clinical stage T2b, T2c, T3, or T4.