FDG-PET for evaluating the antitumor effect of intraarterial 3-bromopyruvate administration in a rabbit VX2 liver tumor model.
OBJECTIVE
We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model.


METHODS
VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology.


RESULTS
The SUV of the VX2 tumors before treatment (3.87+/-1.51 [mean+/-SD]) was significantly higher than that of nontumorous liver parenchyma (1.72+/-0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05+/-1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41+/-0.73) than that before treatment (p = 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48%+/-15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range.


CONCLUSIONS
Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor.
Park
Hee Sun
HS
Department of Radiology, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Medical Research Center and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
Chung
Jin Wook
JW
Jae
Hwan Jun
HJ
Kim
Young Il
YI
Son
Kyu Ri
KR
Lee
Min Jong
MJ
Park
Jae Hyung
JH
Kang
Won Jun
WJ
Yoon
Jung Hwan
JH
Chung
Hesson
H
Lee
Kichang
K
D000818:Animals; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005240:Feasibility Studies; D019788:Fluorodeoxyglucose F18; D007261:Infusions, Intra-Arterial; D007269:Injections, Intra-Arterial; D008114:Liver Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D009336:Necrosis; D049268:Positron-Emission Tomography; D011768:Pyruvate Dehydrogenase Complex / Q000037:antagonists & inhibitors; D011773:Pyruvates / Q000494:pharmacology*; D011817:Rabbits; D019275:Radiopharmaceuticals
D004791:Enzyme Inhibitors; D011768:Pyruvate Dehydrogenase Complex; D011773:Pyruvates; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C017092:bromopyruvate