Update long-term outcome of stereotactic radiosurgery for cerebral arteriovenous malformations

Stereotactic radiosurgery has been widely applied to treat cerebral arteriovenous malformations (AVMs), and various relevant studies have been reported to date. Recently, however, many new facts have been clarified by our up-to-date long-term follow-up study. Here we present our experience in stereotactic radiosurgery using a gamma knife to treat these lesions. The hemorrhagic risk from AVMs was significantly reduced even during the latency period and then was further reduced after obliteration. Advancements in imaging technique realized significantly less frequent complications. However, a small risk of hemorrhage and delayed cyst formation still remained after obliteration, and therefore, even angiographic obliteration, which is one the treatment goals, did not necessarily mean an ultimate cure for AVMs. Therefore, long-term follow-up even after obliteration is essential. At the same time, radiosurgery continues to be an effective treatment in small AVMs with high surgical risks.