Comparative evaluation of FET and FDG for differentiating lung carcinoma from inflammation in mice.
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.
Chang
Chih-Hsien
CH
Institute of Pharmacology, National Yang-Ming University, Taipei, ROC.
Wang
Hsin-Ell
HE
Wu
Shi-Yuan
SY
Fan
Kuo-Hsien
KH
Tsai
Tung-Hu
TH
Lee
Te-Wei
TW
Chang
Shiang-Rong
SR
Liu
Ren-Shyan
RS
Chen
Chieh-Fu
CF
Chen
Chin-Hsiung
CH
Fu
Ying-Kai
YK
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
D005462:Fluorine Radioisotopes; C117289:O-(2-fluoroethyl)tyrosine; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D014443:Tyrosine; D014425:Turpentine