Study Shows Gamma Knife Radiosurgery for Patients with Multiple Brain Metastases is Best for Sparing

The volume of normal brain tissue exposed to radiation during treatment for multiple metastases appears to depend on which stereotactic radiosurgery system is employed, according to a recent study in the Journal of Neurosurgery1. Comparing treatment plans developed for use by three different treatment systems for a single patient (already previously treated with Leksell Gamma Knife®), researchers found that Gamma Knife plans would result in “much smaller normal brain volumes receiving any particular dose” than the two other systems’ plans.

The study compared treatment plans by Washington Fremont Hospital’s (Fremont, Calif.) Leksell Gamma Knife® Perfexion™, the University of Utah’s (Salt Lake City) BrainLAB Novalis™ system and the University of California San Francisco’s Accuray CyberKnife® system and involved a patient with 12 metastatic brain lesions. Gamma Knife is widely regarded as the gold standard for treating brain metastases.

“The discrepancy in normal brain volumes exposed between the Gamma Knife plans and those from CyberKnife and BrainLAB was generally on the order of two to three times lower for the Gamma Knife plans,” says David Larson, M.D., Ph.D., Radiation Oncologist and Co-Medical Director at Washington Fremont Hospital’s Gamma Knife Program. “You could expect that patients and physicians would look more favorably on any radiation therapy treatment option that can demonstrate lower unintended radiation exposure to normal tissues.”

This study is particularly compelling given trends in cancer survival and incidence. A major outcome of improved cancer therapies is that patients are living longer2, which in turn may result in a higher incidence of patients experiencing recurrent brain metastases3. Accordingly, for this growing population of cancer survivors, effective treatment of multiple brain metastases is increasingly essential.