Results of Computed Tomography-guided Stereotactic Biopsy for Intracerebral Mass Lesions

ABSTRACT

OBJECTIVE: The diagnostic results are analyzed in a consecutive 55 patients undergoing computerized tomography(CT)-guided stereotactic brain biopsies. METHODS: There were 32 males and 23 females, and their mean age was 44.9(range 8 to 74) years. The biopsy procedure was generally carried out under local anesthesia. Three to four specimens were obtained with side-biting biopsy needles or cup biopsy forceps, usually from the enhancing portion or central hypodense area within the lesion. In 41 patients of brain tumor, 61% had frozen section guidance intraoperatively. The accuracy of targeting by postoperative CT scan was 95%. RESULTS: The lesions identified were neoplastic disease in 41 cases(75%), vascular disease in three, and infectious process in two. Forty-six cases revealed a definitive diagnosis, and 9 cases(16%) were classified as nondiagnostic. The stereotactic biopsy modified the clinical presumptive diagnosis in fifteen patients(28%), with changing the treatment modality. The final diagnosis was achieved in 8 of 9 failed biopsy patients based on the results from craniotomy(1), second biopsy(3), cerebrospinal fluid study(2), and clinical monitoring(2). The positive biopsy rate was 85% for brain tumors. In 10 cases of brain tumor, the histological studies from biopsied materials and resection tissue were identical. Comparison between the frozen section diagnosis and the final diagnosis based on the permanent sections revealed that they matched in 23(92%) cases. Five patients experienced transient neurological worsening after stereotactic biopsy. CONCLUSION: The representative tissue sampling and intraoperative assessment of sample quality by frozen section examinations can improve the diagnostic yield for the stereotactic brain biopsy. In a small number of patients who had inconclusive results, issues on repeating stereotactic biopsy or open biopsy, clinical and radiological follow-up, or choosing empiric therapy should carefully be considered.