title: F-18 choline PET does not detect increased metabolism in F-18 fluoroethyltyrosine-negative low-grade gliomas.
abstract: OBJECTIVE
  Positron emission tomography (PET) with radiolabeled amino acids provides information on biopsy target and chemotherapy response in patients with low-grade gliomas (LGG). In this article, we addressed whether PET with F-18 choline (CHO) detects increased metabolism in F-18 fluoroethyltyrosine (FET)-negative LGG patients.
  
  
  METHODS
  Six LGG patients with nongadolinium-enhancing (magnetic resonance) FET-negative LGG were imaged with CHO PET. Regions of interest were positioned over tumor and contralateral brain. Uptake of FET and CHO was quantified as count ratio of tumor to contralateral brain.
  
  
  RESULTS
  The mean FET uptake ratio for FET-negative LGG was 0.95 ± 0.03 (mean ± standard deviation). Five tumors did not show increased uptake ratios for CHO (0.96 ± 0.12). Slightly increased CHO uptake was found in 1 patient (1.24), which, however, was not associated with tumor visualization.
  
  
  CONCLUSIONS
  Amino acid and choline uptake appear to behave similar in nongadolinium-enhancing LGG. For clinical purposes, CHO PET is not superior to FET PET.
authors.affiliation: Department of Neurology, Cantonal Hospital, Aarau, Switzerland. roelcke@ksa.ch
authors.forename: Ulrich
authors.initials: U
authors.lastname: Roelcke
authors.forename: Matthias
authors.initials: M
authors.lastname: Bruehlmeier
authors.forename: Martin
authors.initials: M
authors.lastname: Hefti
authors.forename: Thomas
authors.initials: T
authors.lastname: Hundsberger
authors.forename: Egbert U
authors.initials: EU
authors.lastname: Nitzsche
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D002794:Choline / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005188:False Negative Reactions; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D019275:Radiopharmaceuticals; C516370:fluoromethylcholine; C545932:(18F)fluoroethyltyrosine; D014443:Tyrosine; D002794:Choline