Role of stereotactic radiosurgery in the treatment of high-grade cerebral arteriovenous malformation

Arteriovenous malformation (AVM) with a small nidus located in the cortical eloquent areas is difficult to surgically resect without neurological complication, but is a suitable target for stereotactic radiosurgery (SRS). However, lesions with large nidus volume or with deeply located nidus are difficult to safely treat, even by SRS. To explore the optimal treatment strategies for such high-grade cerebral AVM, we reviewed treatment outcomes of SRS using gamma knife surgery (GKS) for patients with high-grade AVM at our institute and in published reports. Although lesions in the thalamus and the brainstem carried higher risk of morbidity after SRS, accumulation of technical knowledge and experience about SRS and technological advances in dose planning have enabled safer treatment of AVM in these locations. Large AVM presents another challenge to SRS treatment. Multimodal treatment, including surgery and endovascular treatment, should be considered. In this setting, staged SRS using GKS or CyberKnife may achieve safer treatment of large cerebral AVM. Further progress in SRS is anticipated to enhance the treatment efficacy for high-grade cerebral AVM while reducing treatment morbidity.