title: Results for local control and functional outcome after linac-based image-guided stereotactic radiosurgery in 190 patients with vestibular schwannoma.
abstract: BACKGROUND
  We assessed local control (LC) and functional outcome after linac-based stereotactic radiosurgery (SRS) for vestibular schwannoma (VS).
  
  
  METHODS
  Between 1998 and 2008, 190 patients with VS were treated with SRS. All patients had tumors <2 cm diameter. Patients received 13.5 Gy prescribed to the 80th isodose at the tumor margin. The primary endpoint was LC. Secondary endpoints were symptomatic control and morbidity.
  
  
  RESULTS
  Median follow-up was 40 months. LC was achieved in 88% of patients. There were no acute reactions exceeding Grade I. Trigeminal nerve dysfunction was present in 21.6% (n = 41) prior to SRS. After treatment, 85% (n = 155) had no change, 4.4,% (n = 8) had a relief of symptoms, 10.4% (n = 19) had new symptoms. Facial nerve dysfunction was present in some patients prior to treatment, e.g. paresis (12.6%; n = 24) and dysgeusia (0.5%; n = 1). After treatment 1.1% (n = 2) reported improvement and 6.1% (n = 11) experienced new symptoms. Hearing problems before SRS were present in 69.5% of patients (n = 132). After treatment, 62.6% (n = 144) had no change, 10.4% (n = 19) experienced improvement and 26.9% (n = 49) became hearing impaired.
  
  
  CONCLUSIONS
  This series of SRS for small VS provided similar LC rates to microsurgery; thus, it is effective as a non-invasive, image-guided procedure. The functional outcomes observed indicate the safety and effectiveness of linac-based SRS. Patients may now be informed of the clinical equivalence of SRS to microsurgery.
authors: Departments for Radiation Oncology, Charité University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
authors: Harun
authors: H
authors: Badakhshi
authors: Reinhold
authors: R
authors: Graf
authors: Dirk
authors: D
authors: Böhmer
authors: Michael
authors: M
authors: Synowitz
authors: Edzard
authors: E
authors: Wiener
authors: Volker
authors: V
authors: Budach
mesh_terms: D005260:Female; D006311:Hearing Disorders / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000517:prevention & control* / Q000628:therapy; D009464:Neuroma, Acoustic / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000009:adverse effects / Q000379:methods*; D020127:Recovery of Function; D016896:Treatment Outcome
keywords: acoustic neurinoma; image-guided intervention; local control; stereotactic radiosurgery; vestibular schwannoma
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