Gamma knife surgery for treatment of central neurocytomas - Report of fourcases

The authors investigated the use of gamma knife surgery (GKS) in the treatm ent of central neurocytoma, a usually benign primary brain tumor of the lat eral and third ventricles. Four patients with subtotally resected or recurr ent central neurocytomas were retrospectively studied. The prescription iso dose was 9 to 13 Gy to the 30 to 50% peripheral isodose line. Pre- and post operative magnetic resonance (MR) images were compared to determine the vol ume reduction following GKS. Follow-up review included annual MR imaging an d clinical evaluation by a neurosurgeon. Follow-up periods ranged from 12 t o 99 months. Marked reduction in tumor size was seen in all four patients; the decrease in tumor volume for each was 48%, 72%, 81%, and 77%, respectively, at the l ast follow-up review. None of the four patients required additional treatme nt and none experienced a decline in neurological function during the follo w-up period. No complications have been noted in any of these patients to d ate. Even though there have been few observations and follow-up time has be en limited, because of the consistency of the response and the lack of obse rved side effects, GKS may be the treatment of choice for subtotally resect ed and recurrent central neurocytomas.