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.

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.

Researchers found that Gamma Knife plans would result in ‘much smaller normal brain volumes receiving any particular dose’ than the two other systems’ plans.

Washington Fremont Hospital Gamma Knife Program radiation oncologist and co-medical director David Larson said 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.

"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," Larson said.