Performance of a 99mTc-labelled 1-thio-β-D-glucose 2,3,4,6-tetra-acetate analogue in the detection of infections and tumours in mice: a comparison with [18F]FDG

Abstract

The aim of this study was to investigate the differences in biological performance between a technetium-99m (Tc)-labelled glucose derivative, the Tc-labelled 1-thio-beta-D-glucose 2,3,4,6-tetra-acetate analogue (Tc-TG) with F-fluoro-2-deoxy-glucose ([F]FDG). Binding of both tracers was performed in vitro to viable tumour cells and bacteria. Both tracers were injected into mice for targeting Staphylococcus aureus thigh muscle infections and subcutaneous rat lymphoma (RMA) tumours by using scintigraphy, or by radioactivity counts in excised tissues to determine the biodistribution. In-vitro binding studies revealed that both tracers bind more effectively to tumour cells expressing the glucose transporter 1 rather than the glucose transporter 2, and this binding was specific for [F]FDG. Tc-TG shows the highest binding to bacteria and, in addition, gives the highest rate of accumulation in infected thigh muscles in mice. Both tracers were rapidly removed from the circulatory system through the kidneys, and the majority of the injected radioactivity accumulated in the urinary bladder. Two hours after the injection radioactivity accumulation in two high-energy-dependent organs, heart, and liver, increased. Within 15 min of the injections, Tc-TG visualized the site of S. aureus infection or the tumour. We conclude that the new tracer Tc-TG may have potential use as a SPECT agent for infection and tumour imaging.