[Radiosurgery of acoustic neurinoma as a minimally invasive alternative to microsurgery].

From April 1992 to July 1998 stereotactic radiosurgery (Gamma Knife) was used to treat 1382 patients; 181 had acoustic neurinomas and were followed up, 44 of them for at least 4 years (48-75 months, median 60). With no mortality control of growth tumor was achieved in all cases but one. It was possible to preserve useful hearing in more than half of the patients (60%). In two patients complications due to the radiation with enlargement of the cystic component were observed. One patient needed additional microsurgical decompression. Three patients suffered transient incomplete facial palsy (one permanent, HBI III), and two patients complained of mild trigeminal neuropathy. One suffered from hydrocephalus and a shunting procedure was necessary. The neurological state improved in 23 patients (52%); five complained of new or worsened deficits. Radiosurgery is an effective alternative treatment for acoustic neurinomas with exceptionally low mortality and morbidity. With respect to preserving cranial nerve function the results are just as good as those of microsurgical resection. Short duration of hospitalization and quick return to normal activities make radiosurgery quite cost effective.