CyberKnife(TM) for the Treatment of Non-Metastatic Prostate Cancer

ABSTRACT

PURPOSE: The radiobiology of prostate cancer favors a hypofractionated dose regimen. We report here our experience with the CyberKnife(TM), demonstrating its efficacy, safety, and feasibility as a treatment modality for non-metastatic prostate cancer. MATERIALS AND METHODS: Between October 2002 and April 2006, 20 patients with biopsy-proven prostate cancer were treated with the CyberKnife(TM). The distribution of clinical risks, as assessed by using D'Amico's definition for risk grouping, was as follows low (4), intermediate (5), and high (11). Three patients received 32 Gy, 7 patients received 34 Gy, and 10 patients received 36 Gy. All patients received the radiation doses in 4 fractions. The rectal and bladder toxicities were graded by using the criteria set forth by the Radiation Therapy Oncology Group (RTOG). RESULTS: The mean patient age was 71.4 years (range, 52-79 years), and the mean follow-up period was 35.5 months (range, 8-74 months). There were 2 acute and 1 late grade 2 gastrointestinal toxicities, and 1 acute and 2 late grade 2 urinary toxicities. The 5-year overall survival rate was 100%, respectively. The 5-year biochemical failure-free rate of the low-risk, intermediate-risk, and high-risk patients was 100%, 100%, and 90.9%, respectively. CONCLUSIONS: CyberKnife(TM) is a safe, well-tolerated, and rather effective treatment for non-metastatic prostate cancer. We obtained a 100% 5-year biochemical failure-free rate in low-risk and intermediate-risk patients. CyberKnife(TM) is a viable option for the treatment of non-metastatic prostate cancer.