title: Combination of MRI and dynamic FET PET for initial glioma grading.
abstract: OBJECTIVE
  MRI and PET with 18F-fluoro-ethyl-tyrosine (FET) have been increasingly used to evaluate patients with gliomas. Our purpose was to assess the additive value of MR spectroscopy (MRS), diffusion imaging and dynamic FET-PET for glioma grading.
  
  
  METHODS
  38 patients (42 ± 15 aged, F/M: 0.46) with untreated histologically proven brain gliomas were included. All underwent conventional MRI, MRS, diffusion sequences, and FET-PET within 3±4 weeks. Performances of tumour FET time-activity-curve, early-to-middle SUVmax ratio, choline / creatine ratio and ADC histogram distribution pattern for gliomas grading were assessed, as compared to histology. Combination of these parameters and respective odds were also evaluated.
  
  
  RESULTS
  Tumour time-activity-curve reached the best accuracy (67%) when taken alone to distinguish between low and high-grade gliomas, followed by ADC histogram analysis (65%). Combination of time-activity-curve and ADC histogram analysis improved the sensitivity from 67% to 86% and the specificity from 63-67% to 100% (p < 0.008). On multivariate logistic regression analysis, negative slope of the tumour FET time-activity-curve however remains the best predictor of high-grade glioma (odds 7.6, SE 6.8, p = 0.022).
  
  
  CONCLUSIONS
  Combination of dynamic FET-PET and diffusion MRI reached good performance for gliomas grading. The use of FET-PET/MR may be highly relevant in the initial assessment of primary brain tumours.
authors.affiliation: Vincent Dunet, MD, BSc, Department of Radiology, Lausanne University Hospital, Rue du Bugnon 46, 1011, Lausanne Switzerland, Tel. +41/795 56 05 68, Fax +41/213 14 43 49, E-mail: Vincent.Dunet@chuv.ch.
authors.forename: V
authors.initials: V
authors.lastname: Dunet
authors.forename: P
authors.initials: P
authors.lastname: Maeder
authors.forename: M
authors.initials: M
authors.lastname: Nicod-Lalonde
authors.forename: B
authors.initials: B
authors.lastname: Lhermitte
authors.forename: C
authors.initials: C
authors.lastname: Pollo
authors.forename: J
authors.initials: J
authors.lastname: Bloch
authors.forename: R
authors.initials: R
authors.lastname: Stupp
authors.forename: R
authors.initials: R
authors.lastname: Meuli
authors.forename: J O
authors.initials: JO
authors.lastname: Prior
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000473:pathology*; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D064847:Multimodal Imaging / Q000379:methods*; D060787:Neoplasm Grading; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014443:Tyrosine / Q000031:analogs & derivatives*
chemical_list: D019275:Radiopharmaceuticals; C545932:(18F)fluoroethyltyrosine; D014443:Tyrosine
keywords: 18F-fluoro-ethyl-tyrosine; ADC histogram; MRI; glioma; grading