Linear accelerator radiosurgery for vestibular schwannomas

Object. Radiosurgery has become a popular treatment for small vestibular schwannomas (VSs). The aim of this study was to review an extensive, single-institution experience with linear accelerator (LINAC) radiosurgery for VSs. Methods. Between July 1988 and August 2005, 390 patients with VSs were treated with LINAC-based radiosurgery at the authors' institution. Patient and treatment variables were prospectively maintained in a computer database. Outcomes were tracked through periodic clinical examinations and annual scanning studies. Multivariate and actuarial statistics were used to analyze rates of local tumor control and complications, including facial and trigeminal neuropathies, after treatment. One- and 2-year actuarial control rates were both 98%, and the 5-year actuarial control rate was 90%. Only four patients (1%) required surgery for tumor growth. Seventeen patients (4.4%) reported facial weakness and 14 patients (3.6%) reported facial numbness after radiosurgery. The risk of these complications rose with increasing tumor volume or increasing radiosurgical dose to the tumor periphery. Since 1994, when doses were deliberately lowered to 1250 cGy, only two patients (0.7%) have experienced facial weakness and two (0.7%) have experienced facial numbness. Conclusions. Radiosurgery provides a safe and effective therapeutic alternative to surgery for small VSs.