title: Identifying at diagnosis the vestibular schwannomas at low risk of growth in a long-term retrospective cohort.
abstract: OBJECTIVE
  Identification at time of diagnosis of those vestibular schwannomas that will not grow.
  
  
  METHODS
  Retrospective cohort study of consecutive patients diagnosed with a sporadic vestibular schwannoma that were entered in the wait-and-scan protocol.
  
  
  METHODS
  Academic referral centre.
  
  
  METHODS
  The study group contained 155 patients with a sporadic vestibular schwannoma first seen in the full 8-year period 2000-2007: continual wait-and-scan (n = 89) and initial wait-and-scan until intervention (n = 66).
  
  
  METHODS
  Tumour growth, defined as more than 2 mm linear difference in any plane between the diagnostic MRI-scan and the last available scan, was related to clinical parameters at diagnosis: localisation of the tumour (solely intracanalicular versus cisternal extension), sudden sensorineural hearing loss, sensorineural hearing loss longer than 2 years and vertigo/instability.
  
  
  RESULTS
  Hearing loss longer than 2 years and an entirely intracanalicular localisation were associated with no tumour growth by univariate and multivariate Cox analysis. Combining both factors at time of diagnosis resulted in a group with low risk of growth (n = 36, median follow-up of 6.2 years) with a Hazard Ratio for growth of 0.37 (95% CI, 0.19-0.69). This subgroup is about 25% of the wait-and-scan population. Thirty-one percent showed growth, while in the remaining higher risk group of 119 patients 62% showed growth. For the growing schwannomas, the median time for growth becoming manifest is 1.9 years after diagnostic MRI.
  
  
  CONCLUSIONS
  In this study on vestibular schwannoma patients that start in a wait-and-scan protocol, about a quarter may be set apart having a low risk for growth. These patients at diagnosis combine a history of hearing loss longer than 2 years and a fully intracanalicular schwannoma. They seem to be not needed yearly MRI checks.
authors.affiliation: Department of Neurosurgery, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: J G
authors.initials: JG
authors.lastname: Wolbers
authors.affiliation: Department of Neurosurgery, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: A H G
authors.initials: AH
authors.lastname: Dallenga
authors.affiliation: Department of Otolaryngology, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: van Linge
authors.affiliation: Department of Neurosurgery, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Te West
authors.affiliation: Department of Otolaryngology, Zaans Medical Centre, Zaandam, the Netherlands.
authors.forename: E E
authors.initials: EE
authors.lastname: Kummer
authors.affiliation: Department of Radiation Oncology, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Méndez Romero
authors.affiliation: Department of Otolaryngology, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: B K H
authors.initials: BK
authors.lastname: Pauw
authors.affiliation: Department of Otolaryngology, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: M H
authors.initials: MH
authors.lastname: Wieringa
mesh_terms: D000368:Aged; D005260:Female; D034381:Hearing Loss / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000150:complications / Q000473:pathology* / Q000628:therapy; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D057832:Watchful Waiting