title: Gamma Knife surgery for facial nerve schwannomas.
abstract: OBJECTIVE
  The aim of this study was to evaluate the tumor control rate and functional outcomes after Gamma Knife surgery (GKS) among patients with a facial nerve schwannoma.
  
  
  METHODS
  The authors reviewed the radiological data and clinical records for 14 patients who had consecutively undergone GKS for a facial nerve schwannoma. Before GKS, 12 patients had facial palsy, 7 patients had hearing disturbance, and 5 patients had undergone partial or subtotal tumor resection. The mean and median tumor volumes were 3707 mm(3) and 3000 mm(3), respectively (range 117-10,100 mm(3)). The mean tumor margin dose was 13.2 Gy (range 12-15 Gy), and the mean maximum tumor dose was 26.4 Gy (range 24-30 Gy). The mean follow-up period was 80.7 months (range 2-170 months).
  
  
  RESULTS
  Control of tumor growth was achieved in all 12 (100%) patients who were followed up for longer than 2 years. After GKS, facial nerve function improved in 2 patients, remained unchanged in 9 patients, and worsened in 3 patients. All patients who had had serviceable hearing at the preliminary examination maintained their hearing at a useful level after GKS. Other than mild tinnitus reported by 3 patients, no other major complications developed.
  
  
  CONCLUSIONS
  GKS for facial nerve schwannomas resulted in excellent tumor control rates and functional outcomes. GKS might be a good primary treatment option for patients with a small- to medium-sized facial nerve schwannoma when facial nerve function and hearing are relatively preserved.
authors.affiliation: Department of Neurosurgery.
authors.forename: Ju Hyung
authors.initials: JH
authors.lastname: Moon
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Chang
authors.forename: Hyun Ho
authors.initials: HH
authors.lastname: Jung
authors.forename: Kyu Sung
authors.initials: KS
authors.lastname: Lee
authors.forename: Yong Gou
authors.initials: YG
authors.lastname: Park
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D003390:Cranial Nerve Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D005154:Facial Nerve / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging / Q000601:surgery; D009442:Neurilemmoma / Q000000981:diagnostic imaging / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D020127:Recovery of Function; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
keywords: GKS = Gamma Knife surgery; Gamma Knife surgery; HB = House-Brackmann; SRS = stereotactic radiosurgery; facial nerve; radiosurgery; schwannoma; stereotactic radiosurgery