Computed tomographic guidance stereotaxis in the management of intracranial mass lesions.

A prototype Brown-Roberts-Welles stereotactic instrument has been used as both a diagnostic and a therapeutic surgical adjunct in cases of intracranial mass lesions. Eighty-three procedures (142 point placements) required computerized guidance stereotaxy. The unit accomplished point intracranial access with an accuracy of greater than 1 mm. Pathological processes included a variety of neoplasms (56 cases), strokes (7 cases), and infections (20 cases) affecting deep regions of the cerebral hemispheres, the ventricular system, the cerebellum, and the rostral brain stem. Procedures were undertaken with the patient under local anesthesia for biopsy (300 point specimens), culture, evacuation, aspiration, endoscopic excision, and implantation of radioisotopes. The techniques and instrumentation for each of these procedures are described. Procedural objectives were satisfactorily accomplished with no mortality and an overall complication rate of 4%. Recovery of tissue specific to establish a histological diagnosis or the etiological factors related to each disease process was realized in 94% of the cases. These results were obtained with scanner utilization times averaging 15 minutes and procedurally related patient recovery periods of less than 4 hours. The value and adaptability of the instrumentation and techniques are illustrated, and potential future applications are discussed.