Role of radiosurgery in the management of high grade AVMs

We consider the role of radiosurgery in the management of high-grade arteriovenous malformations (AVMs) based on our experiences and a review of the literature. In general, the larger the AVM volume is, the higher the risk of complication after radiosurgery, while radiosurgery can be applied to slender-shaped AVMs with a volume of less than 10 cc even if the largest diameter is larger than 3 cm. Staged radiosurgery might be one treatment option for otherwise untreatable AVMs larger than 10 cc with repeated hemorrhage or progressing symptoms, although the indication must be judiciously determined, considering the hemodynamic changes that can occur after radiosurgery. In the treatment of AVMs adjacent to the critical white matter fiber tracts, including the corticospinal tract and the optic radiation, the risk of complication can be reduced by integrating tractography based on diffusion-tensor magnetic resonance imaging. (author)