CyberKnifeCyberKnife Stereotactic Radiosurgery for Low and Intermediate Risk Prostate Cancer

Inclusion Criteria:

1. Histologically proven prostate adenocarcinoma

• Gleason score 2-7 (reviewed by reference lab)
• Biopsy within 6 months of date of registration

2. Clinical stage (CS) T1a-T2b, N0-Nx, M0-Mx (AJCC 6th Edition)

• T-stage and N-stage determined by physical exam and available imaging studies (ultrasound, CT, and/or MRI)
• M-stage determined by physical exam, CT or MRI. Bone scan not required unless clinical findings suggest possible osseous metastases.

3. PSA less than or equal to 20 ng/ml
4. Patients belonging in one of the following risk groups:

• Low: CS T1a-T2a and Gleason 2-6 and PSA less than or equal to 10, or
• Intermediate: CS T2b and Gleason 2-6 and PSA less than or equal to 10, or CS T1b-T2b, and Gleason 2-6 and PSA less than or equal to 20 ng/ml, or Gleason 7 and PSA less than or equal to 10 ng/ml

5. Prostate volume less than or equal to 100 cc

• Determined using: volume = π/6 x length x height x width
• Measurement from CT or ultrasound less than or equal to 90 days prior to registration

6. Eastern Cooperative Oncology Group (ECOG performance status 0-1
7. No prior prostatectomy or cryotherapy of the prostate
8. No prior radiotherapy to the prostate or lower pelvis
9. No implanted hardware or other material that would prohibit appropriate treatment planning or treatment delivery, in the investigator's opinion.
10. Completion of patient questionnaires.
11. Consent signed.
12. Intermediate risk patients may be treated with 4-6 months of hormonal therapy at the discretion of the treating physician.