title: Development of F-18-labeled fluoroerythronitroimidazole as a PET agent for imaging tumor hypoxia.
abstract: OBJECTIVE
  To develop a hydrophilic ligand to image tumor hypoxia at positron emission tomography (PET).
  
  
  METHODS
  Biodistribution of fluorine-18-labeled fluoroerythronitroimidazole (FETNIM) and F-18-labeled fluoromisonidazole (FMISO) was determined at PET and autoradiography in three mammary-tumor-bearing rats. The partition coefficient of FETNIM, FMISO, and misonidazole was determined.
  
  
  RESULTS
  Biodistribution of F-18-labeled FETNIM at 1, 2, and 4 hours showed tumor-to-blood ratios of 2.29 +/- 0.599, 2.41 +/- 0.567 and 8.02 +/- 2.420, respectively, and tumor-to-muscle ratios of 0.66 +/- 0.267, 2.11 +/- 0.347, and 5.92 +/- 2.240, respectively. The tumor-to-blood count density ratio with F-18-labeled FETNIM at 4 hours after injection was significantly higher than with F-18-labeled FMISO. Autoradiographs indicated that both agents could help differentiate hypoxic versus necrotic region in the tumor.
  
  
  CONCLUSIONS
  F-18-labeled FETNIM can help detect tumor hypoxia and is easier to prepare, less costly, and more hydrophilic than F-18-labeled FMISO.
authors.affiliation: Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston 77030.
authors.forename: D J
authors.initials: DJ
authors.lastname: Yang
authors.forename: S
authors.initials: S
authors.lastname: Wallace
authors.forename: A
authors.initials: A
authors.lastname: Cherif
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: M B
authors.initials: MB
authors.lastname: Gretzer
authors.forename: E E
authors.initials: EE
authors.lastname: Kim
authors.forename: D A
authors.initials: DA
authors.lastname: Podoloff
mesh_terms: D000818:Animals; D001345:Autoradiography; D015687:Cell Hypoxia; D003287:Contrast Media; D005260:Female; D005462:Fluorine Radioisotopes; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000000981:diagnostic imaging*; D008920:Misonidazole / Q000031:analogs & derivatives; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging*; D009593:Nitroimidazoles / Q000138:chemical synthesis; D011817:Rabbits; D051381:Rats; D011916:Rats, Inbred F344; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed
chemical_list: D003287:Contrast Media; D005462:Fluorine Radioisotopes; D009593:Nitroimidazoles; C092114:fluoroerythronitroimidazole; C031843:fluoromisonidazole; D008920:Misonidazole