title: Growth Dynamics of Intracranial Tumors in Patients with Neurofibromatosis Type 2.
abstract: OBJECTIVE
  Patients with neurofibromatosis type 2 (NF2) are prone to develop multiple intracranial neoplasms, such as schwannomas of the cranial nerves and meningiomas. The aim of our study was to investigate 1) the median growth rate per year, 2) the growth-free interval, and 3) the growth patterns of NF2-associated intracranial tumors.
  
  
  METHODS
  All available magnetic resonance (MR) images of patients from the regional neurofibromatosis center were collected. The depicted tumors' volumes were then calculated if the tumors met the following inclusion criteria: contrast enhanced T1-weighted MRI datasets had to be available from at least two investigations and tumors had to be measurable on at least two slices.
  
  
  RESULTS
  One-hundred and eighty-eight tumors from 52 patients (20 male, 32 female) met the inclusion criteria for volumetric analysis. Overall, the median follow-up time was 76.5 months per patient (range 13-199 months). After 5 years, the median tumor size was 196% ± 338% for vestibular schwannomas (VS), 204% ± 702% meningiomas (M), 128% ± 64.9% for non-vestibular schwannomas (NVS) and 139% ± 270% for pre-operated tumors of the cerebellopontine angle (TX), respectively. The median time to 20% tumor progression was 21 months for VS, NVS and TX, and 17 months for M. Overall, saltatory growth was the most common growth pattern (46.9%).
  
  
  CONCLUSIONS
  Most NF2-associated tumors display a saltatory growth pattern. Meningiomas and untreated vestibular schwannomas grow rapidly and overall at similar rates. Tumors of the CPA that have been operated on and non-vestibular schwannomas show less relative growth per year.
authors: Department of Neurosurgery, HELIOS Klinikum, Erfurt, Germany. Electronic address: anna.lawsonmclean@gmail.com.
authors: Anna C
authors: AC
authors: Lawson McLean
authors: Department of Neurosurgery, HELIOS Klinikum, Erfurt, Germany.
authors: Steffen K
authors: SK
authors: Rosahl
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008579:Meningioma / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D009442:Neurilemmoma / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D016518:Neurofibromatosis 2 / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery; D009464:Neuroma, Acoustic / Q000150:complications / Q000601:surgery; D055815:Young Adult
keywords: Growth dynamics; Magnetic resonance imaging; Natural history; Neurofibromatosis; Tumors