The authors report on their series of 40 @entity1 with 41 @entity5513 ( @entity5513 ), including one @entity1 with @entity8605 suffering from @entity8605 ( @entity8605 ) who were treated with the gamma knife unit at their institution between August 1992 and October 1995. Of these 41 @entity5 , 21 @entity5513 had been operated on before (1 to 4 times), 20 @entity5513 were exclusively treated by gamma knife radiosurgery (GKRS). The maximal axial @entity5 diameter ranged from 6 to 33 mm (median: 25 mm), the maximal transverse @entity5 diameter ranged from 7 mm to 36 mm (median: 16 mm). The dose distributed to the @entity5 margin was 10 to 17 Gy (median: 12 Gy) by enclosing the @entity5 with the 40% to 95% isodose line (median: 50% isodose line) and using 1 to 12 isocenters (median: 5 isocenters). Central loss of contrast enhancement was observed in 78% of the @entity1 within six to 12 months after radiosurgery. Thirty-two @entity1 were observed over a minimum follow up period of at least 36 months, 9 @entity1 were lost to follow up as they died of unrelated causes or refused further check-ups. Within the follow up period of up to seven years, magnetic resonance imaging (MRI) control scans revealed the @entity5 diameter stable or decreased in 29 cases and increased in three @entity5 . Of 14 @entity1 with useful hearing before treatment, 9 @entity1 were examined in addition to pure tone audiogramm by measurement of brainstem auditory evoked potentials (BAEPs) one to four years after radiosurgery. None of these @entity1 showed a postoperative loss of the cochlea function. According to slight alterations of the cochlea function (cochlea summating action potential), pure tone audiometry of those @entity1 revealed only slight changes of the hearing level (HL) within a maximum range of +/-15 Decibel (dB). The hearing threshold improved in two, was stable in four and deteriorated in three @entity1 , respectively. We observed postradiosurgical aggravation of a pre-existing @entity425 in two out of 13 @entity1 , a new occurrence of @entity3541 was seen in two cases (four years after treatment), one of them was previously operated on and both suffered from @entity528 with mass effect. Tinnitus improved in six out of 13 @entity1 , deteriorated in two and never appeared as a new permanent sequela. Trigeminal hypaesthesia did also not appear as a new permanent symptom, improved in three out of 9, and deteriorated in one out of 9 @entity1 . Vertigo increased in six out of 23, was stable in 8 and decreased in nine out of 23 @entity1 each. GKRS proves to be a safe and highly satisfactory therapeutical option or addition to open surgery, especially for radiologically verified regrowing residual @entity5513 , but also as primary treatment in selected @entity1 . A high rate of @entity5 control can be achieved with an acceptable rate of @entity51 .

Gamma knife radiosurgery of XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity5513 :: ('MESH:D009464', 'Disease') :: ['ACNs', 'acoustic neurinomas'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumour', 'tumours'] @entity425 :: ('MESH:D018908', 'Disease') :: ['facial weakness'] @entity51 :: ('MESH:D009461', 'Disease') :: ['neurological deficits'] @entity8605 :: ('MESH:D016518', 'Disease') :: ['bilateral acoustic neurinomas', 'NF II', 'neurofibromatosis type 2'] @entity3541 :: ('MESH:D005158', 'Disease') :: ['facial palsy'] @entity528 :: ('MESH:D009410', 'Disease') :: ['cystic degeneration']
@entity5513 :: (MESH:D009464,Disease) :: ['acoustic neurinomas']
