As in all fields of surgery, the current trend in neurosurgery is towards less invasive procedures and the shorter hospital stays that result from them. Therefore, stereotactic techniques are an indispensable tool for the modern neurosurgeon and have been dramatically improved by the recent revolution in digital image guidance technology. These techniques provide a relatively straightforward, accurate, and safe method to approach intracranial targets that are defined by either anatomical or functional characteristics. Anatomically defined targets include brain tumors and abscesses as well as other structural lesions. Targeting for anatomical disorders relies entirely on patient-specific anatomy derived from radiographs (e.g., ventriculography) or tomograms (e.g., CT, MRI) for localization. Functionally defined structures include the various nuclei of the basal ganglia and thalamus that are targeted for pain and movement disorders (e.g., Parkinson's disease, essential tremor, and dystonia), as well as other conditions. Targeting for functional disorders combines computerized imaging with intraoperative electrophysiological mapping for localization.

Stereotactic brain biopsy – which is purely diagnostic and does not allow for tumor resection – has been used increasingly during the past decade to aid in the diagnosis and treatment of intracranial lesions, providing a definitive pathologic diagnosis in more than 90% of the patients with a low associated morbidity. On the day of operation, the patient undergoes a contrast-enhanced imaging study (MRI or CT) following the attachment to the cranium of the stereotactic base ring and localizer under local anesthesia and sedation.