CyberKnife® as Monotherapy or Boost SBRT for Intermediate or High Risk Localized Prostate Cancer

The primary objective of this study is to document the effectiveness of Cyberknife stereotactic body radiotherapy (SBRT) in the treatment of intermediate and high-risk localized prostate cancer defined by biochemical Disease-Free Survival (bDFS), using Phoenix and American Society of Therapeutic Radiation and Oncology (ASTRO) definitions, at 5 years.

During the prostate-specific antigen era, an ever-increasing percentage of men with prostate cancer have presented with clinically localized, potentially curable disease. Although conventional treatment options are potentially curative in selected patients, these treatments also have drawbacks, including the risk of negative long-term quality of life consequences and serious complications.

The CyberKnife® system is a type of radiation machine that uses a special system to precisely focus large doses of x-rays on the tumor. The device is designed to concentrate large doses of radiation onto the tumor so that injury from radiation to the nearby normal tissue will be minimal.

Intermediate risk patients will be treated with either CyberKnife® Stereotactic Body Radiation Therapy (SBRT) monotherapy or CyberKnife® SBRT boost followed by Intensity Modulated Radiation Therapy (IMRT). High risk patients will be treated with CyberKnife® SBRT boost followed by IMRT. Treatment will last 4-7 days. Patients will complete the QOL questionnaires before treatment. Questionnaires will also be completed during follow-up visits at 1, 3 , 6, 12, 18, 24, 30 and 36 months then every 12 months until year 5.

The purpose of this project is to evaluate the efficacy and Health-Related Quality of Life (HRQOL) in intermediate and high-risk prostate cancer patients treated with SBRT as monotherapy or as a boost in combination with IMRT.

Eligibility Criteria:
* Patient must be ≥ 18 years of age.
* Histologically proven prostate adenocarcinoma

  * Gleason score 2-10 (reviewed by reference lab)
  * Biopsy within one year of date of registration
  * Clinical stage T1b-T4, N0-Nx, M0-Mx (AJCC 7th Edition)
  * T-stage and N-stage determined by physical exam and available imaging studies (ultrasound, CT, and/or MRI; see section 4.5)
  * M-stage determined by physical exam, CT or MRI. Bone scan not required unless clinical findings suggest possible osseous metastases.
* PSA ≤ 50 ng/ml, CBC, platelets, BUN, creatinine prior to treatment
* Patients belonging in one of the following risk groups:

  * Intermediate: CS T2b-c and Gleason \<6 and PSA ≤ 10, or CS T1b-T2b, and Gleason 7 and PSA ≤ 10 ng/ml, or Gleason \<6 and PSA 11-20 ng/ml
  * High: CS T3-4, Gleason score \>7and PSA\<50
* Prostate volume: ≤ 100 cc

  * Determined using: volume = π/6 x length x height x width
  * Measurement from MRI, CT or ultrasound prior to registration.
* ECOG performance status 0-1
* No prior prostatectomy or cryotherapy of the prostate
* No prior radiotherapy to the prostate or lower pelvis
* No implanted hardware or other material that would prohibit appropriate treatment planning or treatment delivery, in the investigator's opinion.
* No chemotherapy for a malignancy in the last 5 years.
* No history of an invasive malignancy (other than this prostate cancer, or basal or squamous skin cancers) in the last 5 years.