Gamma knife radiosurgery (GKRS) had proven to be a relatively safe and effective therapy for patients with cerebrovascular disease. But, the efficacy of radiosurgery for cerebral cavernous malformations (CMs) was controversial.

     In this study, we evaluate the efficacy and safety of CMs radiosurgery retrospectively.

     Complete follow-up was available in 19 patients (7 women, 12 men). Initial symptoms were headache, focal neurologic deficit, seizure and dizziness.

     Between December 2003 and June 2009, 46 patients with CMs were treated with the GKRS. The location of CMs were brainstem (6 patients), thalamus and basal ganglia (3 patients), cerebellum (4 patients), and cerebral hemisphere (6 patients). Serial magnetic resonance image (MRI) was performed to assess the response. Mean marginal dose was 12.1 Gy for 50% isodose line, which was a little bit lower dose than other usual dosage. The mean follow-up period after radiosurgery was 31 months.

     The annual rebleeding rate after GKRS was 10.3%. After first 2 years following GKRS, the annual rebleeding rate was decreased to 5%. Initial symptoms were almost improved, but two patients suffered from the rebleeding. Complication associated with the post-radiosurgery edema developed in only one patient. The size of CMs after GKRS decreased in 9 patients, increased in 1 patient, and did not changed in others.

     This was a retrospective study.

     It was impossible that the radiosurgery protects patients with CMs against hemorrhage risk, but reduction in the bleeding rate after a latent period might be possible. In our series, lower dosage than other reports was also effective to control symptoms or bleeding risk and the rate of radidation-related complications was not high. 

     We concluded that GKRS with low dose for CMs is effective and safe treatment modality.