Gamma Knife treatment strategies for paediatric AVMs: approaches to refractory cases

Abstract

Introduction: While paediatric arteriovenous malformations (AVMs) often require aggressive therapeutic intervention due to their high bleeding incidence, choosing a course of treatment for deep and eloquent areas and asymptomatic cases is difficult. Sequelae are a concern in children, as they survive for longer after treatment. The authors have long recommended and implemented staged Gamma Knife radiosurgery (GKRS) in their treatment guidelines to maximise therapeutic effects. Methods: Fifty-eight paediatric patients with AVM and ≤15 years old who underwent GKRS under general anesthesia from 2002 to 2020 were followed up for an average of 81·5 months. Obliteration dynamics and clinical outcomes were analysed. Results: The mean patient age was 10·5 years. The mean nidus volume was 6·6 cm3, the complete occlusion rate was 69%, the annual post-irradiation bleeding rate was 2·19% and nine (16%) cases had transient radiation-induced changes. One (1·7%) patient had sequela, and three (5·1%) developed encapsulated hematomas and cysts. Additionally, the 3- and 5-year cumulative occlusion rates were 39·0% and 53·3%, respectively. Multivariate analysis showed significantly higher occlusion rates in patients ≤12 years old and with a nidus volume of ≤4 cm3. Conclusions: GKRS is a useful treatment for paediatric AVM; however, its use poses some challenges.