Radiosurgery of acoustic neurinomas: a minimally invasive alternative to microsurgery

From April 1992 to July 1998 stereotactic radiosurgery (Gamma Knife) was us ed 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 mortal ity control of growth tumor was achieved in all cases but one. lt was possi ble to preserve useful hearing in more than half of the patients (60%). In two patients complications due to the radiation with enlargement of the cys tic component were observed. One patient needed additional microsurgical de compression. Three patients suffered transient incomplete facial palsy (one permanent, HBI III),and two patients complained of mild trigeminal neuropa thy. 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 treatmen t for acoustic neurinomas with exceptionally low mortality and morbidity. W ith respect to preserving cranial nerve function the results are just as go od as those of microsurgical resection. Short duration of hospitalization a nd quick return to normal activities make radiosurgery quite cost effective .