title: Imaging proliferation in human leukemia-tumor bearing mice with (18)F-FLT: Comparison with (18)F-FDG PET.
abstract: Leukemia threatens human life due to its uncontrolled proliferative malignancy.  3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) has been suggested as a new positron emission tomography  (PET) tracer for imaging tumor proliferation. The aim of the study was to investigate the usefulness  of (18)F-FLT PET for imaging human leukemia-tumor bearing mice, compared with  fluorine-18-fluorodesoxyglucose ((18)F-FDG PET). In vitro the experiments  of (18)F-FLT and (18)F-FDG uptake  were performed in K562 cell lines at various time points and radioactive tracer uptake was measured in  a gamma counter. (18)F-FLT and (18)F-FDG PET imaging were performed both in the same mouse when  eight tumor-bearing mice models of human chronic myeloid leukemia were established successfully  by injecting K562 cells. Regions of interest were drawn over the tumor, the crossed normal tissue  was regarded as background and the ratio of tumor to non-tumor counts (T/NT) in tissues was calculated.  A higher uptake of (18)F-FLT (15min, 5.73±0.05%; 30min, 5.90±0.06%; 60min, 6.16±0.19%; 120min, 6.32±0.08%)  than that of (18)F-FDG (15min, 1.05±0.10%; 30min, 1.11±0.14%; 60min, 1.14±0.37%; 120 min, 1.36±0.25%)  was observed in K562 cells in the tracer uptake experiment. Ratios of T/NT of (18)F-FLT PET  (0.5h, 5.39±0.42; 1h, 4.88±0.43; 2h, 3.81±0.38) were higher than those of (18)F-FDG PET/CT  (0.5h, 0.34±0.12; 1h, 0.21±0.06; 2h, 0.13±0.05) after injection. Both uptake and T/NT differences  of (18)F-FLT versus (18)F-FDG were significant (P>0.05).  In conclusion, (18)F-FLT and (18)F-FDG quantitative  and semi-quantitative uptake measurements resulting from cell lines and PET imaging respectively  suggested a promising potential of (18)F-FLT for metabolic imaging of human chronic myeloid leukemia.
authors.affiliation: Department of Nuclear Medicine, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, 200233, Shanghai, China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Lu
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
authors.forename: Haixia
authors.initials: H
authors.lastname: Guan
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Gao
authors.forename: Hankui
authors.initials: H
authors.lastname: Lu
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D015224:Dideoxynucleosides; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D020014:K562 Cells / Q000000981:diagnostic imaging / Q000473:pathology; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D015224:Dideoxynucleosides; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C002854:alovudine