Treating benign tumors outside the brain with CyberKnife Frameless Radiosurgery resulted in significant improvement in symptoms and minimal toxicity, according to a study by University of Pittsburgh School of Medicine researchers presented Oct. 5 at the 46th Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Atlanta.

“While stereotactic radiosurgery for the treatment of benign brain tumors has become widely accepted, our knowledge about the use of this technology for benign tumors outside the brain has been limited,” said Steve Burton, study coauthor and assistant professor in the Pitt medical school’s Department of Radiation Oncology. “The results of our study indicate that treating these tumors with CyberKnife is safe and effective and can successfully control their growth and progression.”

The study, whose purpose was to evaluate the feasibility, toxicity, and local control of patients with symptomatic benign tumors treated with CyberKnife, evaluated 50 benign tumors in 35 patients who underwent radiosurgery between 2001 and 2004 at the University of Pittsburgh Medical Center. The tumors were located in the spine (36), neck (6), skull (3), eye (3) and brainstem (2). Seventy-eight percent of patients treated with CyberKnife experienced an improvement in their pre-treatment symptoms, which included pain and weakness. The local control rate—the rate at which the tumor’s growth was controlled locally—was 96 percent for the 26 patients who underwent followup imaging from one to 25 months after the treatment was administered.

“Our findings demonstrate that CyberKnife may offer a promising treatment option for patients with benign tumors who are not candidates for surgery or whose tumors are not amenable to surgery,” said Burton. “The potential benefits are significant and include short-term treatment time in an outpatient setting with rapid recovery and symptomatic response.”

Burton added that follow-up studies will seek to assess the long-term tumor control rates as well as any future effects.

CyberKnife is a non-invasive robotic radiosurgical device that can remove tumors and other lesions without open surgery, using a robotic arm, controlled by a computer, that sends multiple beams of high-dose radiation directly to the tumor site.