long term effects of gamma knife radiosurgery for treatment of cerebral arteriovenous malformations

abstract background: the gamma knife radiosurgery (gkr) is an established management option for cerebral ar-teriovenous malformations (avms). therapeutic benefits of radiosurgery for arteriovenous malformations are complete obliteration of nidus with minimal neurological deficit. methods: radiosurgery was performed between february 2003 and april 2010 at kamraniye day clinic, teh-ran, iran, using the leksell gamma knife model b (elektra instruments ab, stockholm, sweden) on 82 consecu-tive patients with avms. the male-to-female ratio was 1.4:1(48m, 34f). the age of the patients ranged from 9 to 70 years (mean, 28.5±12 years). the marginal dose to the avm nidus was 45 to 85% (median, 60%) isodose and ranged from 14 to 30 gy (mean, 20.57±13gy).the maximum dose ranged between 20 to 60 gy (mean, 37.5 gy ± 10.17gy ). follow up of patients for complete avm obliteration and in the case of complications mri were performed. results: complete obliteration of avm was achieved in 56 cases (68.29%). it was marked in average 3.62 [sd=3.19] years (from 1 to 5 years) after gkr. partial obliteration (≥50% reduction of the nidus volume) was marked in 24 cases(31%), and less than 50% reduction of the nidus volume was marked in 2 cases(2.4%) with a follow-up of 5 years. complete obliteration of avm had statistically significant associations with smaller score of spetzler-martin arteriovenous malformation grading system for avms. (p< 0.05) conclusion: the gamma knife radiosurgery can offer total and partial obliteration to acceptable percent of treated avm with a low risk of morbidity. higher success observed in patients with spetzler-martin grade i and ii avms, which was attributed to smaller volume of avms in this group.