Gamma knife treatment of intracranial disorders in children

Radiosurgical treatment with a gamma knife was performed on 160 patients with intracranial lesions at Komaki City Hospital from May 1991 through February 1992. Twenty seven of the patients were under 15 years of age: 19 had arteriovenous malformations (AVM), two had craniopharyngiomas and one each had optic glioma, ganglioglioma, pineal teratoma, ependymoma, medulloblastoma and glioblastoma. It is still too early to evaluate the results of treatment, but some early effects have been found in some cases. There was no immediate side effect of this treatment. A decrease of the nidus was found by MRI angiography (MRA) 7 months after treatment in one patient with AVM. In one of the craniopharyngioma patients the low-intensity area (LIA) of the tumor was larger on T1-weighted MRI but smaller 6 months after treatment. An intratumoral LIA was also found in the optic glioma patient 6 months after treatment. There are difficulties in the gamma knife treatment of children, since general anesthesia is needed below 12 years of age, and it is difficult to apply the system below 2 years of age. However, there are advantages: higher radiosensitivity in pediatric AVM and the curability of inoperable lesions without neurological deficit. Radiosurgery for pediatric brain tumors has different indications from those for adults. Patients with small circumscribed benign tumors, such as craniopharyngiomas, optic gliomas, gangliogliomas or pineal tumors are good candidates for radiosurgery. (author)