SUNNYVALE, Calif., May 21, 2013 /PRNewswire/ -- Accuray Incorporated (Nasdaq: ARAY), announced today the publication of study results involving hundreds of prostate cancer patients treated with the CyberKnife® Robotic Radiosurgery System, the most widely used form of prostate stereotactic body radiation therapy (SBRT). The study followed 304 patients for a median of 5 years, and many to 6 years post-treatment and found that 97 percent of patients with low-risk and 90.7% of patients with intermediate-risk prostate cancer remained cancer-free throughout that time. The CyberKnife treatment was also shown to be minimally harmful, producing low levels of toxicity that are similar to the level produced by other radiation treatment options including brachytherapy. Preservation of sexual function was achieved for 75 percent of patients who were sexually potent prior to CyberKnife treatment. The positive quality of life outcomes, low side effects, and brief duration of CyberKnife treatment are especially encouraging for men weighing their many treatment options. "Stereotactic Body Radiotherapy for Localized Prostate Cancer: Disease Control and Quality of life at 6 Years," appears in the May 2013 edition of Radiation Oncology and was led by Dr. Alan Katz, a radiation oncologist with more than 30 years of experience who currently practices at Flushing Radiation Oncology in Queens, N.Y. In related SBRT news, the American Society for Radiation Oncology (ASTRO) recently updated its position on the use of SBRT for prostate cancer. According to its recently posted Model Policy, the Society believes that enough clinical evidence now exists to so that "SBRT could be considered an appropriate alternative for select patients with low to intermediate risk disease." "These latest long-term CyberKnife data coupled with ASTRO's new position on SBRT for prostate cancer confirm what I have seen in my clinical practice," said Dr. Alan Katz. "CyberKnife SBRT is a safe and effective treatment for prostate cancer that offers men the opportunity to complete a non-invasive treatment in five days and should be considered for patients with organ-confined prostate cancer." "Dr. Katz's five-year CyberKnife prostate SBRT data show good disease-free survival, low toxicity, and preservation of sexual function. The data support prior findings that validate an approach to prostate SBRT that includes dynamic tracking and automatic correction for target motion," said Fabienne Hirigoyenberry-Lanson, vice president of medical affairs at Accuray.