[Metabolism of 18F-FDG (2-fluoro-2-deoxy-D-glucose) in tumor cells]

Tumor cell components obtained at 5 min, 1 hr and 3 hr after 18F-FDG injections were analyzed by radio-TLC. Major metabolites were 18F-FDG-phosphate and 18F-FDM-phosphate. 18F-FDM and three unidentified compounds were found as minor metabolites. Time course of the composition of metabolites are as follows; 18F-FDG-phosphate was 88% at 5 min after injection, but decreased to 53% at 3 hr after. 18F-FDM-phosphate was increased to 38% at 3 hr after injection. In conclusion, 18F-FDG is promptly phosphorylated after transportation into cell, and then exists as 18F-FDG-phosphate or 18F-FDM-phosphate. These results support known FDG distribution and metabolism, and it is possible that we use the information accumulated until now employing FDG manufactured by commercial supply system.