Long-term outcomes following stereotactic radiosurgery for pediatric brain arteriovenous malformations: a systematic review.

INTRODUCTION: The long-term outcomes following stereotactic radiosurgery (SRS) for pediatric brain arteriovenous malformations (AVMs) remains poorly understood given the paucity of longitudinal studies. A systematic review was conducted to pool cumulative incidences for all outcomes. METHODS: PubMed, Embase, and Web of Science were queried to systematically extract potential references. The articles relating to AVMs treated via SRS were required to be written in the English language, involve pediatric patients (< 18 years of age), and include a mean follow-up period of > 5 years. Individual patient data were obtained to construct a pooled Kaplan Meier plot on obliteration rates over time. RESULTS: Among the 6 studies involving 1315 pediatric patients averaging a follow-up period of 86.6 months (range: 6-276), AVM obliteration was observed in 66.1% with cumulative probabilities of 48.28% (95% confidence interval [CI]: 41.89-54.68), 76.11% (95%CI 67.50-84.72), 77.48% (95%CI 66.37-88.59) over 3, 5, and 10 years, respectively. The cumulative incidence of post-SRS hemorrhage, tumors, cyst, and denovo seizures were 7.2%, 0.3%, 1.6%, and 1.5%, respectively. The cumulative incidence of radiation induced necrosis, edema, radiological radiation induced changes (RICs), symptomatic RICs, and permanent RICs were 8.0%, 1.4%, 28.0%, 8.7%, and 4.9%, respectively. CONCLUSIONS: Current studies assessing long-term outcomes following SRS are moderate in quality and retrospective in nature. Thus, interpretation with caution is advised given the variable degree in loss to follow-up which suggests that complication rates may be higher than the values stated in the literature. Future prospective studies are needed to validate these findings.