May 11, 2010 - Stereotactic radiosurgery using gamma knife is a safe and effective option for selected children with arteriovenous malformations, according to a recent study presented at the American Association of Neurological Surgeons Annual Meeting in Philadelphia last week.
An intracranial arteriovenous malformation is an abnormal tangle of blood vessels in the brain. In an arteriovenous malformation, the blood passes directly from arteries to veins via the abnormal vessels, and the brain is not allowed to absorb oxygen from the blood, which can result in stroke-like symptoms, seizures or other symptoms. Arteriovenous malformations appear to be congenital. About 0.14 percent of the population has an arteriovenous malformation.
The gamma knife is a radiosurgical treatment that delivers a dose of gamma radiation to the target with surgical precision. It is also the most accepted and widely used radiosurgery treatment in the world.
"Using stereotactic radiosurgery, focused radiation is directed to the arteriovenous malformation causing the vessels to slowly block off over several years and the majority of patients are protected from the risk of intracranial bleeding," said Bruce Pollock, M.D., a Mayo Clinic neurosurgeon and the author of the study.
Pollock and a team of Mayo Clinic researchers collected data from 48 patients, ages 18 or under, who had Gamma Knife stereotactic radiosurgery for an arteriovenous malformation between 1990 and 2007 and had more than 12 months of follow-up data. Twenty-seven patients (57 percent) had a previous brain hemorrhage, and 15 of the arteriovenous malformations were in deep locations. The team found that 52 percent (25 patients) had obliteration of the malformation after their initial radiosurgery. Repeat radiosurgery was performed in 12 patients, five of whom had obliteration, for a total obliteration rate of 63 percent. Three patients had radiation-related deficits after initial or repeat radiosurgery, but no patients had arteriovenous malformation bleeding, neuro-cognitive decline or radiation-induced tumor after radiosurgery.
"We believe that Gamma Knife stereotactic radiosurgery is a safe treatment option for many children with arteriovenous malformations," said Pollack.
For more information: www.mayoclinic.orgstereotactic-radiosurgery/gamma-knife.html and www.aans.org