title: NCI-sponsored trial for the evaluation of safety and preliminary efficacy of 3'-deoxy-3'-[18F]fluorothymidine (FLT) as a marker of proliferation in patients with recurrent gliomas: preliminary efficacy studies.
abstract: OBJECTIVE
  3'-Deoxy-3'-[18F]fluorothymidine ([18F]FLT) is being developed for imaging cellular proliferation. The goals were to explore the capacity of FLT-positron emission tomography (PET) to distinguish between recurrence and radionecrosis in gliomas and compare the results to those obtained with 2-fluoro-2-deoxy-D: -glucose (FDG).
  
  
  METHODS
  Fifteen patients with tumor recurrence and four with radionecrosis, determined by clinical course and magnetic resonance imaging results, were studied by dynamic [18F]FLT-PET with arterial blood sampling. A two-tissue compartment four-rate constant model was used to determine metabolic flux (K (FLT)), blood to tissue transport (K (1)), and phosphorylation (k (3)). FDG-PET scans were obtained 75-90 min postinjection.
  
  
  RESULTS
  K (FLT) and k (3), but not K (1) or k (3)/k (2) + k (3), reached significance for separating the recurrence from radionecrosis groups. Standardized uptake value and visual analyses of FLT or FDG images did not reach significance.
  
  
  CONCLUSIONS
  K (FLT) (flux) appears to distinguish recurrence from radionecrosis better than other parameters, FLT and FDG semiquantitative approaches, or visual analysis of images of either tracer.
authors.affiliation: Department of Neurology, University of Washington, Mailstop 356465, 1959 NE Pacific Street, Seattle, WA 98195, USA. aspence@u.washington.edu
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Spence
authors.forename: Mark
authors.initials: M
authors.lastname: Muzi
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Link
authors.forename: Finbarr
authors.initials: F
authors.lastname: O'Sullivan
authors.forename: Janet F
authors.initials: JF
authors.lastname: Eary
authors.forename: John M
authors.initials: JM
authors.lastname: Hoffman
authors.forename: Lalitha K
authors.initials: LK
authors.lastname: Shankar
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Krohn