Re-Evaluating Clinical Outcomes for AVM Stereotactic Radiosurgery.

Traditional outcome measures after stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVMs) have focused predominantly on angiographic obliteration and general neurologic complications. Several grading scales attempting to predict the outcome for specific patients have previously been proposed and validated, and are outlined here. These have largely been based on both AVM and patient characteristics and attempt to predict obliteration. However, the most practical and clinically oriented goal in the management of AVMs is the prospective avoidance of neurological sequelae manifesting in the form of stroke or death, regardless of AVM obliteration. Long-term outcomes following SRS have demonstrated stroke or death rates of 1.5-2.0% per year for the first 5 years after SRS, followed by 0.2-0.4% annual risk thereafter. This focus on the avoidance of stroke or death is additionally crucial for direct comparisons to non-interventional natural history data. Here, we discuss the history of outcomes data on radiosurgery for AVMs and propose a re-evaluation of clinical outcome that is of most utility to the patient.