Dynamic evaluation of 18F-FDG uptake by microPET and whole-body autoradiography in a fibrosarcoma-bearing mouse model.
OBJECTIVE
Fluorine-18-2-deoxy-D-glucose (18F-FDG) has been used in the clinic as a diagnostic radiotracer for monitoring many kinds of tumors, but its value for monitoring fibrosarcoma is not well established.


METHODS
In this study, the uptake of 18F-FDG in a fibrosarcoma-bearing mouse model was evaluated using the high resolution positron emission tomography (PET) system microPET. Tumor cells were implanted in 3 FVB/N mice, and static microPET scanning was performed on day 1, 7, 12 and 15 after implantation. A dynamic microPET image was scanned on day 12 to determine the 18F-FDG uptake in 3 other tumor-bearing mice. Time-activity curves were plotted by drawing regions of interest in the tumor, liver, kidneys and muscles. The mice were sacrificed after dynamic microPET imaging and whole-body autoradiography (WBAR) was performed. For biodistribution study, 9 tumor-bearing mice, 3 per experimental group, were studied at 3 time points and the results were compared with the static microPET images.


RESULTS
MicroPET images suggested that 18F-FDG could be used to monitor the growth of tumors 7 days after implantation. Dynamic scans of 18F-FDG uptake reached a plateau in the tumor after 20 minutes on day 12 after implantation. Both microPET and WBAR revealed evidence of tumor necrosis. The results of biodistribution and WBAR agreed with those from microPET images.


CONCLUSIONS
MicroPET was useful for monitoring the growth of fibrosarcoma and determination of the maximal uptake time point of 18F-FDG in tumors in this tumor-bearing mouse model.
Chang
Chih-Hsien
CH
Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.
Fan
Kuo-Hsien
KH
Chen
Te-Jung
TJ
Hsu
Wei-Chun
WC
Jan
Mei-Ling
ML
Tsai
Tung-Hu
TH
Kao
Pan-Fu
PF
Chen
Chieh-Fu
CF
Fu
Ying-Kai
YK
Lee
Te-Wei
TW
D000818:Animals; D001345:Autoradiography; D005260:Female; D005354:Fibrosarcoma / Q000000981:diagnostic imaging*; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D051379:Mice; D023421:Models, Animal; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18