Reproducibility of the kinetic analysis of 3'-deoxy-3'-[(18)F]fluorothymidine positron emission tomography in mouse tumor models.
OBJECTIVE
We assessed the reproducibility of the kinetic analysis of 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) positron emission tomography (PET) in A431 human epidermoid carcinoma and murine Lewis lung carcinoma (LLC) tumor models.


METHODS
We injected 7.4 MBq of FLT (n=10 for each group) and acquired 2-h dynamic PET images. A second scan was performed 1 day later. We calculated standardized uptake value (SUV), kinetic rate constants, volume of distribution of phosphorylated FLT (V(dm)), net influx constant (K(FLT-CA)) and influx constant by Patlak graphical analysis (K(FLT-PA)). The percent difference between measurements of a parameter was calculated to compare the reproducibilities of different parameters.


RESULTS
FLT phosphorylation was higher in mice with A431 tumors than in mice with LLC tumors (P<.005). Differences in the standard deviations of the percent differences of parameters were statistically significant (P<.001) in each model. In mice with A431 tumors, SUV, V(dm), K(FLT-CA) and K(FLT-PA) had standard deviations of the percent difference of < or = 20%. The most reproducible parameter was K(FLT-PA), although the standard deviation (15.6%) was not statistically different from those of V(dm) (15.8%), K(FLT-CA) (17.5%) and SUV (18.9%). In mice with LLC tumors, K(1), K(1)/k(2) and k(3) had standard deviations of the percent difference of < or = 20%. No macroparameters reflecting a total FLT flux had standard deviations of < or = 20%.


CONCLUSIONS
Our results show the reproducibility of the kinetic macroparameters of FLT PET in mouse tumors with high FLT phosphorylation.
Choi
Seung Jin
SJ
Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, South Korea.
Kim
Seog Young
SY
Kim
Su Jin
SJ
Lee
Jae Sung
JS
Lee
Sang Ju
SJ
Park
Soo Ah
SA
Lee
Seung Jin
SJ
Yun
Sung-Cheol
SC
Im
Ki Chun
KC
Oh
Seung Jun
SJ
Kim
Sang-We
SW
Kim
Jae Seung
JS
Ryu
Jin Sook
JS
Moon
Dae Hyuk
DH
D000818:Animals; D018827:Carcinoma, Lewis Lung / Q000000981:diagnostic imaging*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging*; D045744:Cell Line, Tumor; D015224:Dideoxynucleosides; D004195:Disease Models, Animal; D006801:Humans; D007700:Kinetics; D008297:Male; D051379:Mice; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results
D015224:Dideoxynucleosides; C002854:alovudine