Tumor cell uptake of 99mTc-labeled 1-thio-β-D-glucose and 5-thio-D-glucose in comparison with 2-deoxy-2-[18F]fluoro-D-glucose in vitro: kinetics, dependencies, blockage and cell compartment of accumulation.

PURPOSE: This study was conducted to investigate the capacity of (99m)Tc-labeled 1-thio-β-D-glucose ((99m)Tc-1-TG) and 5-thio-D-glucose ((99m)Tc-5-TG) to act as a marker for glucose metabolism in tumor cells in vitro. PROCEDURES: We investigated the cellular uptake of (99m)Tc-1-TG, (99m)Tc-5-TG, and 2-deoxy-2-[(18)F]fluoro-D-glucose((18)F-FDG) in a human colorectal carcinoma and human lung adenocarcinoma cell line (HCT-116, A549) at different time points and varying glucose/insulin concentrations and under transporter blockage by cytochalasin-B and phloretin. Cell compartment analysis was performed.
RESULTS: A significant uptake and time dependency thereof, a significant uptake dependency on glucose and insulin and a significant uptake inhibition by cytochalasin-B for (99m)Tc-1-TG and (99m)Tc-5-TG, was shown. Albeit substantial, the uptake was less pronounced in (99m)Tc-1-TG and (99m)Tc-5-TG compared with (18)F-FDG. (99m)Tc-1-TG and (99m)Tc-5-TG showed a higher accumulation in the cell membranes compared with (18)F-FDG.
CONCLUSION: Tc-1-TG and (99m)Tc-5-TG showed an uptake in vitro with glucose analog characteristics but with membranous accumulation. Tumor imaging should be investigated in an animal model.