PET 2-fluoro-2-deoxyglucose uptake in rat prostate adenocarcinoma during chemotherapy with gemcitabine.
This study was performed to investigate the effect of the new chemotherapeutic agent gemcitabine on glucose transport and metabolism in prostate carcinoma in vitro and in vivo.


METHODS
After transplantation of rat prostate adenocarcinoma cells, dynamic PET measurements with fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose (18FDG) were performed in 15 animals before and 1 day after therapy with 90 mg/kg of body weight (n = 8) and 180 mg/kg of body weight (n = 7) gemcitabine. In the second examination, the animals received a simultaneous injection of 18FDG and [3H]thymidine. Quantitative evaluation of the PET data was done using the standardized uptake value (SUV) as well as a three-compartment pharmacokinetic model. Furthermore, the incorporation of [3H]thymidine into the DNA was determined. In vitro measurements of the FDG, 3-O-methylglucose and thymidine uptake were performed immediately and 4 hr after a 24-hr incubation period with different doses of gemcitabine.


RESULTS
FDG-SUV and the metabolic rate of FD 3 utilization did not change significantly after therapy. However, the values for the transport rate constants K1 and K2 increased significantly. The incorporation of thymidine into the DNA of treated tumors showed an 80% decline as compared with a control group. In the cell culture experiments, a dose-dependent increase of FDG (up to 178%) and 3-O-methylglucose uptake (up to 305%) was demonstrated. The thymidine uptake showed a 96% decline in the nucleic acid fraction and an increase of up to 337% in the cytoplasmic fraction.


CONCLUSIONS
The more global measures of FDG metabolism as SUV and metabolic rate of FDG utilization were unchanged after therapy, while DNA synthesis and cell viability declined. However, in vitro and in vivo evidence of an enhancement of glucose transport is presented, indicating that quantification by modelling may be superior for the evaluation of metabolic effects during chemotherapy.
Haberkorn
U
U
Department of Oncological Diagnostics and Therapy, German Cancer Research Center, Heidelberg, Germany.
Bellemann
M E
ME
Altmann
A
A
Gerlach
L
L
Morr
I
I
Oberdorfer
F
F
Brix
G
G
Doll
J
J
Blatter
J
J
van Kaick
G
G
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism*; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D001692:Biological Transport; D004273:DNA, Neoplasm / Q000187:drug effects; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism; D008297:Male; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors; D013936:Thymidine; D014055:Tomography, Emission-Computed; D014316:Tritium; D014407:Tumor Cells, Cultured; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D004273:DNA, Neoplasm; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D003841:Deoxycytidine; D019788:Fluorodeoxyglucose F18; D014316:Tritium; D003847:Deoxyglucose; D012264:Ribonucleotide Reductases; D005947:Glucose; D013936:Thymidine; D000093542:Gemcitabine