Results for local control and functional outcome after linac-based image-guided stereotactic radiosurgery in 190 patients with vestibular schwannoma

Background we assessed local control (lc) and functional outcome after linac-based stereotactic radiosurgery (srs) for vestibular schwannoma (vs). methods between 1998 and 2008,190 patients with vs were treated with srs. all patients had tumors <2 cm diameter. patients received 13.5 gy prescribed to the 80th isodose at the tumor margin. the primary endpoint was lc. secondary endpoints were symptomatic control and morbidity. results median follow-up was 40 months. lc was achieved in 88% of patients. there were no acute reactions exceeding grade i. trigeminal nerve dysfunction was present in 21.6% (n = 41) prior to srs. after treatment,85% (n = 155) had no change,4.4,% (n = 8) had a relief of symptoms,10.4% (n = 19) had new symptoms. facial nerve dysfunction was present in some patients prior to treatment,e.g. paresis (12.6%; n = 24) and dysgeusia (0.5%; n = 1). after treatment 1.1% (n = 2) reported improvement and 6.1% (n = 11) experienced new symptoms. hearing problems before srs were present in 69.5% of patients (n = 132). after treatment,62.6% (n = 144) had no change,10.4% (n = 19) experienced improvement and 26.9% (n = 49) became hearing impaired. conclusion this series of srs for small vs provided similar lc rates to microsurgery; thus,it is effective as a non-invasive,image-guided procedure. the functional outcomes observed indicate the safety and effectiveness of linac-based srs. patients may now be informed of the clinical equivalence of srs to microsurgery. © 2013 the author 2013. published by oxford university press on behalf of the japan radiation research society and japanese society for therapeutic radiology and oncology.