140 patients with brain tumor were treated byCT-guided stereotactic injections of radionuclides,such as Aurum-198(198 Au),Phosphorus-32(32 P)and Yttrium-90(90Y).Of these patients aged from 3to 67 years(average 37),64 were male and 76 female.Astrocytoma was found in 75 patients,cranioph-aryngioma in 46,metastatic carcinoma in 7,meningioma in 5,germinoma in 4 and pituitaryadenoma in 3.The tumors were located in the deeppart or functionally critical area of the brain.After267 times of injection of colloidal isotopes,no majoradverse effects or complications occurred.Follow-upfor 6 to 48 months showed improvement in symptomsin 104(74.3%)patients and CT scanning showed thediminished tumors.