Imaging with 99mTc ECDG targeted at the multifunctional glucose transport system: feasibility study with rodents.
OBJECTIVE
To evaluate the feasibility of technetium 99m ((99m)Tc) ethylenedicysteine-deoxyglucose (ECDG) imaging in tumor-bearing rodents.


METHODS
ECDG was synthesized by means of reacting ethylenedicysteine with glucosamine, with carbodiimide as the coupling agent. Hexokinase assays were performed at an ultraviolet wavelength of 340 nm. To determine whether blood glucose level could be altered, ECDG or glucosamine was injected into six rats. In a separate study, ECDG followed by insulin was administered to three rats. To determine biodistribution, lung tumor cells were intramuscularly injected into the hind legs of 18 nude mice. The animals were then injected with (99m)Tc ECDG or fluorine 18 ((18)F) fluorodeoxyglucose (FDG) (0.037-0.074 MBq per mouse). Radioactivity was measured in tissue excised from the animals. Scintigraphy was performed in three groups: in group 1 to demonstrate that different-sized tumors could be imaged after (99m)Tc ECDG administration, in group 2 to ascertain whether tumor uptake of (99m)Tc ECDG was perfusion related, and in group 3 to demonstrate that tumor uptake of (99m)Tc ECDG occurred by means of a glucose-mediated process.


RESULTS
ECDG was positive for phosphorylation at hexokinase assay. Blood glucose level increased with ECDG injection and decreased with insulin administration. Tumor-to-brain tissue and tumor-to-muscle tissue ratios of (99m)Tc ECDG uptake were higher than those of (18)F FDG uptake. Scintigraphic results demonstrated the feasibility of (99m)Tc ECDG imaging.


CONCLUSIONS
There are similarities between (99m)Tc ECDG uptake and (18)F FDG uptake in tumors, and study findings supported the potential use of (99m)Tc ECDG as a functional imaging agent.
Yang
David J
DJ
Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. dyang@di.mdacc.tmc.edu
Kim
Chang-Guhn
CG
Schechter
Naomi R
NR
Azhdarinia
Ali
A
Yu
Dong-Fang
DF
Oh
Chang-Sok
CS
Bryant
Jerry L
JL
Won
Jong-Jin
JJ
Kim
E Edmund
EE
Podoloff
Donald A
DA
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000493:pharmacokinetics; D005240:Feasibility Studies; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D007328:Insulin / Q000494:pharmacology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D051379:Mice; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D051381:Rats; D014018:Tissue Distribution
C471673:(99m)Tc ethylenedicysteine-deoxyglucose; D001786:Blood Glucose; D007328:Insulin; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D003545:Cysteine