Improving outcomes in patients with vestibular schwannomas: microsurgery versus radiosurgery.

Vestibular schwannomas (VSs) account for 6% of all intracranial tumors. Historically, VSs have been treated with microsurgery (MS); however, stereotactic radiosurgery (SRS) has emerged as a viable alternative. This review seeks to compare the tumor control rates, functional outcomes, and costs associated with these two modalities. A focused review of the published literature (1966-2012) was conducted comparing outcomes between MS and SRS in those with VS. Outcomes of interest included hearing preservation, facial nerve preservation, tumor control, and cost-effectiveness. Three level 2 studies, eight level 3 studies, and several level 4 studies were reviewed and assessed. Evidence from level 2 studies show that SRS (40-68%) results in higher rates of serviceable hearing compared to MS (0-5%), and higher rates of facial nerve preservation are likewise seen after SRS (98-100%) compared to MS (66-83%) in patients with tumors <3 cm in size. Complications vary as expected by treatment modality, with CSF leak, tinnitus, and trigeminal symptoms being among the most common complications following MS. Hydrocephalus, tinnitus, and trigeminal symptoms were reported in a small percentage of patients after SRS. Tumor control is comparable between MS and SRS for tumors <3cm in size. Total costs for MS can reach over two times higher than for SRS, although long-term follow-up data is needed. SRS has been shown to be efficacious and have a lower morbidity in most patients with tumors that are <3cm. SRS can be considered as the primary modality of choice for treatment of most VS that are <3cm.