title: Image-guided stereotactic radiotherapy for patients with vestibular schwannoma. A clinical study.
abstract: BACKGROUND
  Local tumor control and functional outcome after linac-based stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for vestibular schwannoma (VS) were assessed.
  
  
  METHODS
  In all, 250 patients with VS were treated: 190 patients with tumors < 2 cm diameter underwent SRS and 60 patients with tumors >2 to 3.5 cm underwent FSRT. Dose prescription for all cases with SRS (n = 190, 76 %) was 13.5 Gy. For FSRT, mainly two hypofractionated schedules (n = 60, 24 %) with either 7 fractions of 5 Gy (total dose: 35 Gy; n = 35) or 11 fractions of 3.8 Gy (total dose: 41.8 Gy; n = 16) were used. The primary endpoint was local tumor control. Secondary endpoints were symptomatic control and morbidity.
  
  
  RESULTS
  The median follow-up was 33.8 months. The 3-year local tumor control was 88.9 %. Local control for SRS and FSRT was 88 and 92 %, respectively. For FSRT with 35 and 41.8 Gy, local control was 90 and 100 %, respectively. There were no acute reactions exceeding grade I. In 61 cases (24.4 % of the entire cohort), trigeminal neuralgia was reported prior to treatment. At last follow-up, 16.3 % (10/61) of those patients reported relief of pain. Regarding facial nerve dysfunction, 45 patients (18 %) presented with symptoms prior to RT. At the last follow-up, 13.3% (6/45) of those patients reported a relief of dysesthesia.
  
  
  CONCLUSIONS
  Using SRS to treat small VS results in good local control rates. FSRT for larger lesions also seems effective. Severe treatment-related complications are not frequent. Therefore, image-guided stereotactic radiotherapy is an appropriate alternative to microsurgery for patients with VS.
authors.affiliation: Departments for Radiation Oncology, Charité School of Medicine and University Hospital of Berlin, Augustenburger Platz 1, 13353, Berlin, Germany, Harun.Badakhshi@charite.de.
authors.forename: H
authors.initials: H
authors.lastname: Badakhshi
authors.forename: S
authors.initials: S
authors.lastname: Muellner
authors.forename: E
authors.initials: E
authors.lastname: Wiener
authors.forename: V
authors.initials: V
authors.lastname: Budach
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis; D016634:Radiosurgery / Q000379:methods*; D012086:Reoperation; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed