Stereotactic radiosurgery of acoustic tumors

Surgery has long been the most common treatment for vestibular schwannomas (acoustic neuromas), but over the past ten years stereotactic radiosurgery has emerged as an alternative to microsurgery for selected patients. The four therapeutic options presented to patients now include total vs. partial microsurgical resection, stereotactic radiotherapy, or serial observation. Magnetic resonance imaging (MRI) has largely replaced computed tomography (CT) as the preferred imaging modality for tumor localization. Dose-planning software has improved so that complicated dose plans involving multiple isocenters of radiation can be developed in less than one hour. There has been a gradual reduction in the radiation dose delivered to the tumor margin (from 20 Gy to 10-14 Gy), resulting in decreased neurologic complications. These advances in technique have brought the results of stereotactic radiotherapy for small tumors to the point where they may be compared to those of microsurgical resection.