Stereotactic Radiosurgery for Pediatric High-Grade Brain Arteriovenous Malformations: Our Experience and Review of Literature

Abstract

Introduction: Although high-grade AVMs pose a particularly high lifetime hemorrhage risk to pediatric patients (age <18 years), little is known about the treatment outcomes. Therefore, the aim of this retrospective cohort study was to evaluate the outcomes after single-session stereotactic radiosurgery (SRS) for pediatric high-grade AVMs.

Methods: We reviewed baseline and treatment outcomes data from pediatric patients aged less than 18 years with Spetzler-Martin grade IV AVMs treated with SRS in a single session at our institution. The study cohort comprised 28 pediatric patients with Spetzler-Martin grade IV AVMs, with a mean age of 12.1 years. Statistical analyses were performed to determine predictors of obliteration and compare the outcomes of patients with versus without previous AVM hemorrhage.

Results: The mean nidus volume, radiosurgical margin dose, and follow-up duration were 5.9 cm³, 19.4 Gy, and 116 months, respectively. The actuarial obliteration rates at 3, 5, 7, and 10 years were 11%, 19%, 29%, and 35%, respectively. Older age was significantly associated with obliteration in the univariate Cox proportional regression analysis (P = 0.01). During the latency period before obliteration, the annual post-SRS hemorrhage rate was 3.2%. Symptomatic and permanent radiation-induced changes were detected in 7.1% and 3.5%, respectively. A favorable outcome was achieved in 35.7%, and it was more frequently achieved for those with ruptured AVMs (P = 0.0484).

Conclusions: The efficacy of single-session SRS for the treatment of high-grade AVMs in the pediatric population is limited, particularly for those with unruptured nidi. Multimodal therapies should be considered in the management of selected pediatric high-grade AVMs. However, further prospective analyses are warranted to define the optimal management strategy for these challenging vascular malformations.

Keywords: Gamma Knife; Intracranial arteriovenous malformation; Intracranial hemorrhages; Pediatric; Radiosurgery; Spetzler-Martin grade IV and V; Stroke; Vascular malformations.