title: Conservative management of acoustic neuroma: an outcome study.
abstract: OBJECTIVE
  This study analyzed selection criteria, clinical outcome, and tumor growth rates in patients with acoustic neuromas in whom the initial management strategy was observation.
  
  
  METHODS
  A retrospective review of patients with conservatively managed unilateral acoustic neuromas was conducted. Minimum follow-up was 6 months. Patients with neurofibromatosis Type II were excluded. Differences in tumor growth rates were analyzed by use of the Wilcoxon rank sum test.
  
  
  RESULTS
  Sixty-eight patients (31 men and 37 women) with a mean age of 67.1 years were followed for an average of 3.4 years after diagnosis. The reasons for a trial of observation included advanced age (55%), patient preference (21%), minimal symptoms (9%), poor general medical condition (7%), asymptomatic tumor (4%), and tumor in the only hearing ear (4%). Fifty-eight patients (85%) were successfully managed with observation alone. Ten patients (15%) ultimately required treatment (nine received microsurgical treatment and one patient underwent radiosurgical intervention) at a mean time interval of 4.0 years after diagnosis. Forty-eight tumors (71%) showed no growth and 20 (29%) enlarged during the study period. The mean tumor growth rate at the 1-year follow-up was significantly higher in the group requiring treatment (3.0 mm) than in the group not requiring treatment (0.36 mm) (P < 0.0001). Thus, the tumor growth rate at the 1-year follow-up was a strong predictor of the eventual need for treatment.
  
  
  CONCLUSIONS
  Observation is a reasonable management strategy in carefully selected patients with acoustic neuromas. Diligent follow-up with serial magnetic resonance imaging is recommended, because some tumors will enlarge to the point at which active treatment is required.
authors.affiliation: Department of Neurosurgery, Mayo Clinic Scottsdale, Arizona, USA.
authors.forename: H G
authors.initials: HG
authors.lastname: Deen
authors.forename: M J
authors.initials: MJ
authors.lastname: Ebersold
authors.forename: S G
authors.initials: SG
authors.lastname: Harner
authors.forename: C W
authors.initials: CW
authors.lastname: Beatty
authors.forename: M S
authors.initials: MS
authors.lastname: Marion
authors.forename: R E
authors.initials: RE
authors.lastname: Wharen
authors.forename: J D
authors.initials: JD
authors.lastname: Green
authors.forename: L
authors.initials: L
authors.lastname: Quast
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002455:Cell Division / Q000502:physiology; D002530:Cerebellopontine Angle / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000473:pathology / Q000628:therapy*; D016634:Radiosurgery; D012189:Retrospective Studies; D016896:Treatment Outcome