Gamma-knife surgery may be an effective alternative for treatment of
central neurocytomas owing to its relative safety compared with conventional
radiotherapy. In this paper we present results of gamma-knife treatment (GKS) of residual or recurrent
neurocytomas. Twenty-two patients (14 female, 8 male) with recurrent or residual
neurocytomas who underwent GKS were included. Diagnosis was based on histological findings. The proliferative potential of the
tumors was examined by immunostaining with
MIB-1 antibody, which is specific for detection of
Ki-67 antigen.
Tumor volume was determined by using post-
gadolinium magnetic resonance images. After GKS treatment, MR imaging was scheduled at three-month intervals in the first year, at six months intervals in the second year, and yearly thereafter. Histopathological diagnoses were: 18 cases of
central neurocytomas, two liponeurocytomas, one cerebral
neurocytoma and one cerebellar
neurocytoma. The MIB1 labeling index (LI) varied from 0 to 5.7%. Marked reduction in
tumor volume was seen in 15 patients. In six patients, the
tumor volume remained unchanged, and progression was observed for one patient. No complications because of GKS were noted. Shrinking effect on
tumor volume increased with increasing duration of follow-up. On the other hand, high MIB labeling index did not seem to have an effect on
tumor response to GKS treatment. Findings of this study suggest that GKS is an effective and safe treatment alternative for residual or recurrent
neurocytomas. However, its effectiveness should be confirmed with larger studies.