title: Comparative effectiveness of 18F-FDG PET/CT versus whole-body MRI for detection of malignant peripheral nerve sheath tumors in neurofibromatosis type 1.
abstract: OBJECTIVE
  The aim of this study was to compare the diagnostic performance of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT and whole-body MRI for the detection of malignant peripheral nerve sheath tumors (MPNSTs) in patients with neurofibromatosis type 1, and to evaluate a panel of imaging-based criteria serving that purpose.
  
  
  METHODS
  Thirty-one patients were examined by whole-body MRI and ¹⁸F-FDG PET/CT. A panel of imaging-based criteria including tumor region, size, shape, margin definition, contrast enhancement, heterogeneity before and after contrast, intratumoral lobulation, target sign, and mean and maximum standardized uptake values (SUVs) were evaluated. A SUVmax cut-off value of 3.5 was used for lesion analysis. Histopathologic evaluation and/or clinical follow-up served as the reference standard.
  
  
  RESULTS
  ¹⁸F-FDG PET/CT had a sensitivity of 100%, whereas MRI had a sensitivity of 66.7%. On PET/CT, tumor size (P<0.005), SUVmax (P<0.0001), SUVmean (P<0.0001), and tracer uptake heterogeneity (P=0.002) were significantly associated with MPNSTs. On MRI, intratumoral lobulation (P<0.02), ill-defined margins (P=0.007), and irregular enhancement on T1-weighted imaging (P<0.001) were significantly associated with MPNSTs.
  
  
  CONCLUSIONS
  Both PET/CT and whole-body MRI may distinguish benign and malignant PNSTs, but PET/CT has higher sensitivity for that purpose. Imaging-based criteria for identification of MPNSTs on both modalities were identified. False-positive results, requiring biopsy or clinical follow-up, may be reduced by using a combination of MRI and PET derived markers, but only at the price of reduced sensitivity.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. t.derlin@uke.uni-hamburg.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Derlin
authors.forename: Katharina
authors.initials: K
authors.lastname: Tornquist
authors.forename: Silvia
authors.initials: S
authors.lastname: Münster
authors.forename: Ivayla
authors.initials: I
authors.lastname: Apostolova
authors.forename: Christian
authors.initials: C
authors.lastname: Hagel
authors.forename: Reinhard E
authors.initials: RE
authors.lastname: Friedrich
authors.forename: Ulrike
authors.initials: U
authors.lastname: Wedegärtner
authors.forename: Victor F
authors.initials: VF
authors.lastname: Mautner
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D057186:Comparative Effectiveness Research; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D018317:Nerve Sheath Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D009456:Neurofibromatosis 1 / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18