Stereotactic radiosurgery in the treatment of patients with acoustic tumors.

Stereotactic radiosurgery is performed under local anesthesia, and most patients can be discharged from the hospital within 24 hours of treatment. All patients in our series returned to their preoperative level of employment or function within 5 to 7 days of treatment, and this functional level was maintained over the period of follow-up. "Tumor control" was achieved in 96% of patients during an average follow-up of 1.7 years. Tumor shrinkage occurred in 45% of patients who had at least 1.5 years of follow-up. Useful hearing preservation rates were 50% at 6 months and 30% 1 year after treatment. New delayed facial or trigeminal neuropathy occurred in 34% and 32% of patients, respectively, with a median onset of 5 to 6 months after treatment. The vast majority of cranial neuropathies were partial at onset and tended to improve over time. Other complications included tumor growth (4%), communicating hydrocephalus (4%), and transient adjacent brain parenchymal changes best seen on T2-weighted MRI (9%). Stereotactic radiosurgery is an important alternative treatment for carefully selected patients with acoustic tumors. Indications for treatment include sufficient medical problems to pose excessive surgical risk, advanced age, the presence of bilateral acoustic tumors or contralateral deafness, recurrent tumor despite surgical resection, or refusal to undergo microsurgery. Radiosurgery is contraindicated in patients with symptomatic brain stem or cerebellar compression from a large acoustic tumor. Previous posterior fossa radiotherapy is a relative contraindication that must be considered on a patient to patient basis. Stereotactic radiosurgery should be viewed as an additional weapon in our arsenal for combating acoustic tumors rather than feared as a potential replacement for surgical excision. The strategic role of stereotactic radiosurgery in the overall treatment of patients with acoustic tumors will continue to be refined as longer-term, carefully assessed results become available.