title: Imaging with 99mTc ECDG targeted at the multifunctional glucose transport system: feasibility study with rodents.
abstract: 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.
authors.affiliation: Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. dyang@di.mdacc.tmc.edu
authors.forename: David J
authors.initials: DJ
authors.lastname: Yang
authors.forename: Chang-Guhn
authors.initials: CG
authors.lastname: Kim
authors.forename: Naomi R
authors.initials: NR
authors.lastname: Schechter
authors.forename: Ali
authors.initials: A
authors.lastname: Azhdarinia
authors.forename: Dong-Fang
authors.initials: DF
authors.lastname: Yu
authors.forename: Chang-Sok
authors.initials: CS
authors.lastname: Oh
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Bryant
authors.forename: Jong-Jin
authors.initials: JJ
authors.lastname: Won
authors.forename: E Edmund
authors.initials: EE
authors.lastname: Kim
authors.forename: Donald A
authors.initials: DA
authors.lastname: Podoloff
mesh_terms: 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
chemical_list: C471673:(99m)Tc ethylenedicysteine-deoxyglucose; D001786:Blood Glucose; D007328:Insulin; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D003545:Cysteine