Systematic Review and Meta-Analysis of the Dose-Response and Risk Factors for Obliteration of Arteriovenous Malformations Following Radiosurgery: An Update Based on the Last 20 Years of Published Clinical Evidence

Abstract

\n \n \n Intracranial arteriovenous malformation (AVM) is a congenital lesion that can potentially lead to devastating consequences if not treated. Many institutional cohort studies have reported on the outcomes after radiosurgery and factors associated with successful obliteration in the last few decades.\n \n \n \n To quantitatively assess the dose-response relationship and risk factors associated with AVM obliteration using a systematic review and meta-analysis approach.\n \n \n \n Data were extracted from reports published within the last 20 yr. The dose-response fit for obliteration as a function of marginal dose was performed using inverse-variance weighting. Risk factors for AVM obliteration were assessed by combining odds ratios from individual studies using inverse-variance weighting.\n \n \n \n The logistic model fit showed a clear association between higher marginal dose and higher rates of obliteration. There appeared to be a difference in the steepness in dose-response when comparing studies with patients treated using Gamma Knife radiosurgery (Elekta), compared to linear accelerators (LINACs), and when stratifying studies based on the size of treated AVMs. In the risk-factor analysis, AVM obliteration rate decreases with larger AVM volume or AVM diameter, higher AVM score or Spetzler-Martin (SM) grade, and prior embolization, and increases with compact AVM nidus. No statistically significant associations were found between obliteration rate and age, sex, prior hemorrhage, prior aneurysm, and location eloquence.\n \n \n \n A marginal dose above 18\xa0Gy was generally associated with AVM obliteration rates greater than 60%, although lesion size, AVM score, SM grade, prior embolization, and nidus compactness all have significant impact on AVM obliteration rate.\n