Tumor Cell Uptake of 99mTc-Labeled 1-Thio-β-d-Glucose and 5-Thio-d-Glucose in Comparison with 2-Deoxy-2-[18 F]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.