Objective: Frameless stereotactic brain biopsy has become an established procedure in many Neurosurgical centers worldwide. the aims was to established the safety and accuracy, as well as diagnostic yield of frameless brain biopsy. Subject and method: 17 men and 6 women, aged from 18 to 81 (mean 51.9 years) underwent brain biopsy with the frameless stereotactic technique for intracranial lesions from July to December 2014. The magnetic resonance imaging (MRI) was indicated preoperatively in all of the patients. The diagnostic yield, lesion size, mean target point deviation, operation time, histological results and complications of the procedure were analyzed. Result: Twenty four diagnostic biopsies in 23 patients were evaluated. Diagnostic yield was 95.8 percent. Lesion size ranged from 0.17 to 8.8cm (mean 3.8cm)
mean target point deviation was 3.5mm. The average operation time was 92 minutes. Histological diagnosis showed GBM in 7 cases, grade III glioma in 4, grade I or II in 8, brain abcess in 2, cystececosis in 1 and meningitis tuberculosis in 1. Complications included two symptomatic hemorrhages (8.7 percent) and one progressive brain edema. Conclusion: Fameless sterotactic brain biopsy using Stealth Station system (Medtronic, USA) could be carried out safely with a good diagnostic yield and high accuracy.