title: Stereotactic radiotherapy of vestibular schwannoma : Hearing preservation, vestibular function, and local control following primary and salvage radiotherapy.
abstract: OBJECTIVE
  The aim of this publication is to present long-term data on functional outcomes and tumor control in a cohort of 107 patients treated with stereotactic radiotherapy (RT) for vestibular schwannoma.
  
  
  METHODS
  Included were 107 patients with vestibular schwannoma (primary or recurrent following resection) treated with stereotactic RT (either fractioned or single-dose radiosurgery) between October 2002 and December 2013. Local control and functional outcomes were determined. Analysis of hearing preservation was limited to a subgroup of patients with complete audiometric data collected before treatment and during follow-up. Vestibular function test (FVT) results could be analyzed in a subset of patients and were compared to patient-reported dizziness.
  
  
  RESULTS
  After a mean follow-up of 46.3 months, actuarial local control for the whole cohort was 100% after 2, 97.6% after 5, and 94.1% after 10 years. In patients with primary RT, serviceable hearing was preserved in 72%. Predictors for preservation of serviceable hearing in multivariate analysis were time of follow-up (odds ratio, OR = 0.93 per month; p = 0.021) and pre-RT tumor size (Koos stage I-IIa vs. IIb-IV; OR = 0.15; p = 0.031). Worsening of FVT results was recorded in 17.6% (N = 3). Profound discrepancy of patient-reported dizziness and FVT results was observed after RT. In patients with primary RT, worsening of facial nerve function occurred in 1.7% (N = 1).
  
  
  CONCLUSIONS
  Stereotactic RT of vestibular schwannoma provides good functional outcomes and high control rates. Dependence of hearing preservation on time of follow-up and initial tumor stage has to be considered.
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany. florian.putz@uk-erlangen.de.
authors.forename: Florian
authors.identifier: http://orcid.org/0000-0003-3966-2872
authors.initials: F
authors.lastname: Putz
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Müller
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Caterina
authors.initials: C
authors.lastname: Wimmer
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Goerig
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Knippen
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Friedrich-Alexander-University Erlangen-Nuremberg, Waldstraße 1, 91054, Erlangen, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Iro
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Friedrich-Alexander-University Erlangen-Nuremberg, Waldstraße 1, 91054, Erlangen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Grundtner
authors.affiliation: Department of Neurosurgery, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054, Erlangen, Germany.
authors.forename: Ilker
authors.initials: I
authors.lastname: Eyüpoglu
authors.affiliation: Department of Neurosurgery, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054, Erlangen, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Rössler
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Semrau
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Fietkau
authors.affiliation: Department of Radiation Oncology, Friedrich-Alexander-University Erlangen-Nuremberg, Universitaetsstraße 27, 91054, Erlangen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lettmaier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D004244:Dizziness / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D005858:Germany / Q000453:epidemiology; D034381:Hearing Loss / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D006320:Hearing Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000517:prevention & control; D009464:Neuroma, Acoustic / Q000453:epidemiology* / Q000532:radiotherapy*; D015995:Prevalence; D011832:Radiation Injuries / Q000517:prevention & control*; D016634:Radiosurgery / Q000706:statistics & numerical data*; D012307:Risk Factors; D016879:Salvage Therapy / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D014724:Vestibular Function Tests / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Audiometry; Dizziness; Hearing loss; Radiosurgery; Vestibular function tests