Development and testing of a radiosurgery-based arteriovenous malformation grading system.

Stereotactic radiosurgery is an accepted management option for many patients with intracranial arteriovenous malformations (AVMs). The Spetzler-Martin grading scale is the most widely accepted and utilized method to predict outcomes after surgical resection of intracranial AVMs but is not sensitive to factors that correlate with successful AVM radiosurgery. The need for a system that accurately predicts patient outcomes after AVM radiosurgery led to the development of the radiosurgery-based AVM score (RBAS). The RBAS has evolved and has been modified over the years to reflect changes in AVM radiosurgical technique and has been validated by numerous centers using the Gamma Knife®, modified LINAC and the CyberKnife®. Use of the RBAS permits an accurate prediction of outcomes from radiosurgery to guide choices between observation, surgical resection or radiosurgery for individual AVM patients, and should be used in future studies on AVM radiosurgery to stratify patients for more precise comparative analyses.