Radiosurgery for Cavernous Malformations

Lim, Young Jin

Abstract

Cavernous malformations (CM) are vascular lesions that comprise the majority of vascular malformations with arteriovenous malformations (AVM). Microsurgical resection of CMs is the preferred management for patients with symptomatic lesion. But in group of patients with hemorrhagic cavernous malformations located in critical brain regions that were thought to pose an excessive risk for microsurgical resection. GKRS has been used as an alternative management approach for this lesions since first application by Karolinska institute in 1985. The favorable results of Gamma Knife radiosurgery (GKRS) for AVMs prompted pilot series in which GKRS was used to treat cavernous malformations. Some authors had suggested that GKRS could reduce the annual rate of hemorrhage, especially after 2-4 years latency interval. The problem with evaluating treatment results in cases of CMs is that, unlike in AVMs, that no imaging modality accurately identifies obliteration of the CM after radiosurgery. To evaluate the potential protection against hemorrhage, the incidence of posttreatment hemorrhage must be compared with the natural course of the disease. Another problem associated with radiosurgical treatment of CMs is that the radiation-induced complication rate appears to be greater than expected compared with that associated with radiosurgery of AVMs. So, radiosurgery for cavernous malformations remains controversial until present time. The clinical application of radiosurgery in CMs needs further investigation, in particular, issues of patient selection, methods of follow-up, long-term risks, and safe dose levels must be addressed.