title: Hearing preservation up to 3 years after gamma knife radiosurgery for Gardner-Robertson class I patients with vestibular Schwannomas.
abstract: BACKGROUND
  Vestibular schwannoma patients with Gardner-Robertson (GR) class I hearing seek to maintain high-level hearing whenever possible.
  
  
  OBJECTIVE
  To evaluate hearing outcomes at 2 to 3 years in GR class I patients who underwent Gamma Knife radiosurgery (GKRS).
  
  
  METHODS
  Sixty-eight patients with GR class I hearing were identified between 2006 and 2009. Twenty-five patients had no subjective hearing loss (group A) and 43 patients reported subjective hearing loss (group B) before GKRS. The median tumor volume (1 cm) and tumor margin dose (12.5 Gy) were the same in both groups.
  
  
  RESULTS
  Serviceable hearing retention rates (GR grade I or II) were 100% for group A compared with 81% at 1 year, 60% at 2 years, and 57% at 3 years after GKRS for group B patients. Group A patients had significantly higher rates of hearing preservation in either GR class I (P < .001) or GR class II (P < .001). Patients with a pure tone average (PTA) <15 dB before GKRS had significantly higher rates of preservation of GR class I or II hearing.
  
  
  CONCLUSIONS
  At 2 to 3 years after GKRS, patients without subjective hearing loss or a PTA <15 dB had higher rates of grade I or II hearing preservation. Modification of the GR hearing classification into 2 groups of grade I hearing (group A, those with no subjective hearing loss and a PTA <15 dB; and group B, those with subjective hearing loss and a PTA >15 dB) may be useful to help predict hearing preservation rates at 2 to 3 years after GKRS.
authors.affiliation: *Departments of Neurological Surgery and §Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; ‡University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: Seyed H
authors.initials: SH
authors.lastname: Mousavi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kano
authors.forename: Amir H
authors.initials: AH
authors.lastname: Faraji
authors.forename: Abhiram
authors.initials: A
authors.lastname: Gande
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: Ajay
authors.initials: A
authors.lastname: Niranjan
authors.forename: Edward
authors.initials: E
authors.lastname: Monaco
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D034381:Hearing Loss / Q000209:etiology; D006320:Hearing Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000150:complications / Q000601:surgery*; D016634:Radiosurgery; D012189:Retrospective Studies