Outcomes of Volume-Staged Radiosurgery for Cerebral Arteriovenous Malformations Larger Than 20 cm3 with More Than 3 Years of Follow-Up

In our series, volume-staged SRS for AVMs >20 cm3 achieved a nidus obliteration rate of 35% at 5 years. There was still a high risk for hemorrhage (∼4% per year) after treatment, which seemed to be higher than the rate commonly observed in the posttreatment course of single-session SRS for average-size AVMs. Further cases will help determine whether volume-staged SRS could be routinely considered, based on its efficacy and risks, including comparison with the natural history of large AVMs.