Radiosurgery for Cerebral Arteriovenous Malformations

From September 1991 to May 1997, a total of 59 patients diagnosed with cerebral arteriovenous malformations were treated using radiosurgery. There were 29 men and 30 women, with an age range of 5 to 75 years (mean 36). Of these patients, 39 patients were treated using a LINAC-based system (group 1) and 20 using the Leksell γ-knife unit (group 2). Tumor volume ranged from 0.38 to 35 cc, and the number of isocenters varied from 1 to 3 in group 1 and from 2 to 15 in group 2. Lesion location was as follows: 14 temporal, 8 basal ganglionic, 8 frontal, 6 parietal, 6 thalamic, 5 intraventricular, 5 cerebellar, 3 brain stem, 3 occipital, and 1 corpus callosal. Seven patients underwent prior embolization and three patients had prior surgery with incomplete resection of their lesions. The marginal radiation dose ranged between 1500 and 2000 cGy with a mean of 1800 cGy. Twelve patients had concomitant embolization done on the morning of radiosurgery. Follow-up ranged from 1 month to 4 years. Thirty-six patients have been followed for more than 1 year. Thirty had an angiography during the follow-up period that showed complete obliteration of the lesion in 28 patients. The rate of obliteration was estimated to be 47.1% at 1 year, 82.3% at 2 years and 88.2% at 3 years.