It is important to document AVM radiosurgery outcomes.

     The authors analyzed the clinical, neuroimaging outcomes and complications past one yearIt in patients with cerebral arteriovenous malformations after Gamma Knife radiosurgery, focusing on the analysis of the obliteration rate depending on the AVM volume.

     Between 2006 and 2011, 406 prospective patients with cerebral AVMs were treated with Gamma Knife radiosurgery(GKRS) and follow up by R tatistical analysis . Of these patients, 272 cases were followed up for >1 years, 160 cases were follow up for > 2 years. The mean age was 30,603±13,48 (6-76) the mean volume 8,990 cm3 ± 13,241(0,0187- 135,00 cm3), the mean marginal dose was 21,365± 3,04 Gy (range 13-26), and the mean follow up duration was 21,255 ± 13,58 months (range 1-52,3). The authors reduced the prescription dose by various amounts, depending on the AVM volume and location as prescribed in the classic guideline to avoid irreversible radiation injuries.

     We evaluated the records in all AVM radiosurgery patients at our center.

     The angiographic obliteration rate was 75% overall, and it was 90%, 39,4% and for small, medium for more than 1 years follow up. And after 2 years 93,8% overall,and it was 97% and 75,8%, respectively, obliterated time 15,805± 6,44 months (10-36), For medium AVMs ( volume > 10cm3), the obliterated time 22,615± 7,26 months (12-36). The overall bleeding rate was 1,9%. The annual bleeding rate was 1% and 2% for small and large AVMs. Six patients experienced bleeding during the latency period, and two suffered lethal hemorrhage. Symptomatic early complications were extensive brain edema after GKRS in six patient with large AVMs and an adverse effect on the internal capsule in two, one of them decrease symptom after 1 year, the others has been recovered with corticoid treatment after 6 months.

     Although data was collected prospectively, the analysis was retrospective and did not include a control group.

     Gamma Knife radiosurgery is a safe and effective treatment for selected patients with AVMs, and it carries a low risk of first hemorrhage from brain arteriovenous malformations and damaging adjacent critical vascular structures.

     Even ruptured AVMs with relatively large diameter can be successfully treated, especially in younger patients, with minimal morbidity and a low risk of repeated hemorrhage.