Gamma Knife Radiosurgery for Symptomatic Cavernous Malformations: Tokyo Women's Medical University Experience

This retrospective study evaluated the results of Gamma Knife surgery (GKS) for symptomatic cavernous malformations (CM) of the brain.

From 1993 till 2014, 11 patients (mean age 44 years) with a symptomatic CM underwent GKS at Tokyo Women's Medical University. In six cases, the disease manifested with hemorrhaging. Seizures and a neurological deficit were noted in four patients each. The CM were located in the brainstem (in 5 cases), basal ganglia (in 2 cases), thalamus (in 2 cases), and cerebral lobe (in 2 cases). The mean lesion volume was 1.46 cc. The mean marginal dose was 15.3 Gy. The mean length of follow-up after GKS was 78.5 months.

At the last follow-up, the general status was considered excellent, fair, and poor in 8 patients (73%), 1 patient (9%), and 2 patients (18%), respectively. The annual hemorrhage rates per case-year were 2.94% from birth till GKS, 20.20% from the first hemorrhage till GKS, 4.54% within the first 2 years after GKS, and 1.39% within the entire follow-up period after GKS. Two patients attained seizure-free status after treatment.

GKS may be considered as a possible management option for symptomatic CM, since it reduces the subsequent hemorrhage risk after the initial bleeding episode. Moreover, in some patients, cessation of symptomatic epilepsy after treatment may be expected.