title: Comparative evaluation of FET and FDG for differentiating lung carcinoma from inflammation in mice.
abstract: BACKGROUND
  Clinical FDG/PET (2-deoxy-2-18F-fluoro-D-glucose/positron emission tomography) studies encounter difficulties in detecting early stage lung cancers. The aim of this study was to evaluate the ability of O-2-18F-fluoroethyl-L-tyrosine (FET) and FDG to differentiate between inflammation and lung carcinoma in mice.
  
  
  METHODS
  Sixty-four C57BL/6 mice were inoculated with 2x10(6) LLC1 lung carcinoma cells in the right hind flank on day 0 and were then injected with 0.1 mL turpentine in the left thigh muscle on day 3. The progress of inflammation and tumor in mice was longitudinally monitored by FDG/microPET. The biodistribution study, pharmacokinetic evaluation and whole-body autoradiography of FET and FDG were performed on day 8 after tumor inoculation.
  
  
  RESULTS
  The FDG uptakes in tumor and inflammatory lesions were 4.42-fold and 3.53-fold (n = 4) higher, respectively, than that in muscle at 90 min post-injection and the tumor-to-inflammation ratio was 1.25. For FET/microPET, the tumor uptake was 2.07-fold and 2.07-fold (n = 4) higher than those in muscle and inflammatory lesions at 90 min post-injection, respectively. The distribution half-life (t1/2,alpha) and the elimination half-life (t1/2,beta) of FET were 39 min and 205 min, respectively, in mice.
  
  
  CONCLUSIONS
  FDG delineated both tumor and inflammation, while FET accumulated in tumor to a significantly higher extent. Our results demonstrated the potential of FET to distinguish epidermoid lung carcinoma from inflammatory lesions in mice.
authors.affiliation: Institute of Pharmacology, National Yang-Ming University, Taipei, ROC.
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Chang
authors.forename: Hsin-Ell
authors.initials: HE
authors.lastname: Wang
authors.forename: Shi-Yuan
authors.initials: SY
authors.lastname: Wu
authors.forename: Kuo-Hsien
authors.initials: KH
authors.lastname: Fan
authors.forename: Tung-Hu
authors.initials: TH
authors.lastname: Tsai
authors.forename: Te-Wei
authors.initials: TW
authors.lastname: Lee
authors.forename: Shiang-Rong
authors.initials: SR
authors.lastname: Chang
authors.forename: Ren-Shyan
authors.initials: RS
authors.lastname: Liu
authors.forename: Chieh-Fu
authors.initials: CF
authors.lastname: Chen
authors.forename: Chin-Hsiung
authors.initials: CH
authors.lastname: Chen
authors.forename: Ying-Kai
authors.initials: YK
authors.lastname: Fu
mesh_terms: D000818:Animals; D001345:Autoradiography / Q000379:methods; D018827:Carcinoma, Lewis Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D003937:Diagnosis, Differential; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011014:Pneumonia / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014425:Turpentine; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D005462:Fluorine Radioisotopes; C117289:O-(2-fluoroethyl)tyrosine; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D014443:Tyrosine; D014425:Turpentine