Abstract
Stereotactic radiosurgery using a gamma knife obtains good results for small intracranial disease, arteriovenous malformation (AVM) and acoustic neurinoma. In this study, accuracy of the radiation method of stereotactic radiosurgery using a LINAC was investigated and preliminary treatment results were also evaluated. The deviation of rotation center of the LINAC gantry was within 0.5mm. However, the deviation of rotation center of the LINAC table was more than 0.5mm. To apply the LINAC target positioner manipulator, the deviation of rotation center of the LINAC table was improved to within 0.5mm. Between July 1992 and November 1994, 25 patients recieved stereotactic radiosurgery using a LINAC. All patients had a small intracranial lesion, AVM ; 6, primary brain tumor ; 9 (acoustic neurinoma ; 4, meningioma ; 2, astrocytoma ; 2 and pineal tumor ; 1) and metastatic brain tumor ; 10. Two of 6 AVMs and one of 4 acoustic neurinomas decreased in size. Seven of 10 metastatic brain tumors either shrunk or disappeared. It is suggested that stereotactic radiosurgery is more effective than whole brain irradiation for metastatic brain tumor. In only one patient who had AVM, post irradiation brain edema appeared. Optimal dose to control tumors remains to be determined by accumulation of further clinical experiences.
