title: The usefulness of dynamic O-(2-18F-fluoroethyl)-L-tyrosine PET in the clinical evaluation of brain tumors in children and adolescents.
abstract: Experience regarding O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) PET in children and adolescents with brain tumors is limited.
  
  
  METHODS
  Sixty-nine (18)F-FET PET scans of 48 children and adolescents (median age, 13 y; range, 1-18 y) were analyzed retrospectively. Twenty-six scans to assess newly diagnosed cerebral lesions, 24 scans for diagnosing tumor progression or recurrence, 8 scans for monitoring of chemotherapy effects, and 11 scans for the detection of residual tumor after resection were obtained. Maximum and mean tumor-to-brain ratios (TBRs) were determined at 20-40 min after injection, and time-activity curves of (18)F-FET uptake were assigned to 3 different patterns: constant increase; peak at greater than 20-40 min after injection, followed by a plateau; and early peak (≤ 20 min), followed by a constant descent. The diagnostic accuracy of (18)F-FET PET was assessed by receiver-operating-characteristic curve analyses using histology or clinical course as a reference.
  
  
  RESULTS
  In patients with newly diagnosed cerebral lesions, the highest accuracy (77%) to detect neoplastic tissue (19/26 patients) was obtained when the maximum TBR was 1.7 or greater (area under the curve, 0.80 ± 0.09; sensitivity, 79%; specificity, 71%; positive predictive value, 88%; P = 0.02). For diagnosing tumor progression or recurrence, the highest accuracy (82%) was obtained when curve patterns 2 or 3 were present (area under the curve, 0.80 ± 0.11; sensitivity, 75%; specificity, 90%; positive predictive value, 90%; P = 0.02). During chemotherapy, a decrease of TBRs was associated with a stable clinical course, and in 2 patients PET detected residual tumor after presumably complete tumor resection.
  
  
  CONCLUSIONS
  Our findings suggest that (18)F-FET PET can add valuable information for clinical decision making in pediatric brain tumor patients.
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany Department of Neurology, University of Cologne, Cologne, Germany.
authors.forename: Veronika
authors.initials: V
authors.lastname: Dunkl
authors.affiliation: Department of Neurology, University of Cologne, Cologne, Germany.
authors.forename: Corvin
authors.initials: C
authors.lastname: Cleff
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Stoffels
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany.
authors.forename: Natalie
authors.initials: N
authors.lastname: Judov
authors.affiliation: Department of Neurosurgery, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Sevgi
authors.initials: S
authors.lastname: Sarikaya-Seiwert
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Ian
authors.initials: I
authors.lastname: Law
authors.affiliation: Department of Neurosurgery, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Bøgeskov
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Karsten
authors.initials: K
authors.lastname: Nysom
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Sofie B
authors.initials: SB
authors.lastname: Andersen
authors.affiliation: Department of Neurosurgery, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Hans-Jakob
authors.initials: HJ
authors.lastname: Steiger
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany Department of Neurology, University of Cologne, Cologne, Germany.
authors.forename: Gereon R
authors.initials: GR
authors.lastname: Fink
authors.affiliation: Department of Neuropathology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Reifenberger
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany.
authors.forename: Nadim J
authors.initials: NJ
authors.lastname: Shah
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany.
authors.forename: Heinz H
authors.initials: HH
authors.lastname: Coenen
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany Department of Nuclear Medicine, University of Aachen, Aachen, Germany; and.
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Langen
authors.affiliation: Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany Department of Neurology, University of Cologne, Cologne, Germany Center of Integrated Oncology (CIO), University of Cologne, Cologne, Germany n.galldiks@fz-juelich.de.
authors.forename: Norbert
authors.initials: N
authors.lastname: Galldiks
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D018365:Neoplasm, Residual; D049268:Positron-Emission Tomography; D012008:Recurrence; D012680:Sensitivity and Specificity; D014443:Tyrosine / Q000031:analogs & derivatives*
chemical_list: C117289:O-(2-fluoroethyl)tyrosine; D014443:Tyrosine
keywords: FET PET; children; contrast-enhanced MRI; glioma; kinetic pattern of 18FF-FET uptake; metabolic imaging