Definition

A uniformly-labeled radioconjugate composed of glutamine, a naturally occurring non-essential amino acid, in which all five carbons are labeled with the isotope 13C, with potential imaging application. Upon administration of uniformly-labeled [13C]glutamine, the glutamine is taken up and metabolized by tumors and the 13C-containing metabolites can be imaged by 13C nuclear magnetic resonance (NMR) spectroscopy. Since tumor cells take up and metabolize glutamine in higher amounts and through different pathways than normal cells, this agent may help assess the metabolic phenotype of the tumor.