title: Repeated treatment of vestibular schwannomas after gamma knife radiosurgery.
abstract: OBJECTIVE
  When gamma knife radiosurgery (GKS) does not achieve control of the growth of a tumour, the need to repeat treatment is considered. The results and risks of repeat treatment of patients with a vestibular schwannoma were reviewed to assess its efficacy and safety.
  
  
  METHODS
  Between 1992 and 2001, we treated 351 patients with a vestibular schwannoma by GKS, control of the growth of the tumour was not achieved in 32. 26 patients underwntrepeat GKS and five patients had an open microsurgical operation and one stereotactic aspiration of a tumour cyst.
  
  
  RESULTS
  Twenty-four of 26 patients were followed up after the repeat GKS for a median of 43 months. 15 tumours became smaller, seven remained unchanged and two enlarged. After the second GKS one patient's hearing deteriorated, one developed facial weakness and three facial spasms. One patient required insertion of ventriculo-peritoneal drainage. An operation to radically resect the tumour was performed in five patients after the first GKS and for a subtotal removal in one after repeated GKS.
  
  
  CONCLUSIONS
  In the small proportion of patients (9%) in whom initial GKS does not control the growth of a vestibular schwannoma, most can be controlled by further GKS with a very low risk of a complications.
authors.affiliation: Stereotactic and radiation neurosurgery, Na Homolce Hospital, Roentgenova 2, Prague, Czech Republic. roman.liscak@homolka.cz
authors.forename: Roman
authors.initials: R
authors.lastname: Liscak
authors.forename: Vilibald
authors.initials: V
authors.lastname: Vladyka
authors.forename: Dusan
authors.initials: D
authors.lastname: Urgosik
authors.forename: Gabriela
authors.initials: G
authors.lastname: Simonova
authors.forename: Josef
authors.initials: J
authors.lastname: Vymazal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020220:Facial Nerve Injuries / Q000453:epidemiology; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000601:surgery; D009464:Neuroma, Acoustic / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000453:epidemiology*; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods* / Q000706:statistics & numerical data; D012086:Reoperation / Q000009:adverse effects / Q000706:statistics & numerical data; D018570:Risk Assessment; D014725:Vestibular Nerve / Q000473:pathology / Q000601:surgery; D055815:Young Adult