Stereotactic biopsy for multifocal, diffuse, and deep-seated brain tumors using Leksell's system.

Using the Leksell stereotactic system, we selectively performed 91 biopsies for surgically inaccessible brain lesions. There were 25 multiple (27.5%), 15 diffuse (16.5%), and 51 (56.0%) deep-seated lesions. However, we avoided subjecting the patients with lesions adjacent to major vascular trunks or complex vascular structures such as the cavernous sinus, peri-insular regions and the pineal regions to stereotactic biopsy. The diagnosis was histologically confirmed in 84 cases (92.3%). Sixty-nine (75.8%) lesions were primary tumors; 44 (48.4%) were malignant gliomas, 18 (19.8%) malignant lymphomas, and five (5.5%) low-grade gliomas. Thirteen (14.3%) cases had previously undergone radiation and/or chemotherapy for brain tumors, seven had recurrent glioma (five with malignant transformation) and six manifested radiation necrosis. None of the patients died due to the stereotactic procedure; one (1.1%) exhibited morbidity due to complicated hemorrhage. We found asymptomatic minor bleeding occurred in nine (9.9%) patients; the rate of hemorrhage was significantly higher in patients with preoperative angiographic evidence of tumor stain. Two patients (2.2%) suffered seizures, in one case seizure was induced by electric stimulation test at the target site. All five patients younger than 15 years underwent the procedure without complications. The Leksell stereotactic system is useful for diagnostic tissue sampling and contributes effectively to the selection of appropriate therapy in patients with malignant brain tumors. While it carries a low morbidity rate without mortality in our series, care must be taken for selected target sites in highly vascularized lesions exhibiting positive tumor stains.