Synthesis and evaluation of a technetium-99m-labeled diethylenetriaminepentaacetate-deoxyglucose complex ([99mTc]-DTPA-DG) as a potential imaging modality for tumors.

This study describes the radiolabeling and preliminary biologic testing of diethylenetriaminepentaacetic acid (DTPA)-deoxyglucose (DG) labeled with (99m)Tc. A one-step [(99m)Tc]-DTPA-DG kit was prepared using the stannous chloride reduction method. When (99m)TcO(4)(-) was added to the DTPA-DG kit at room temperature the radiochemical purity 30 min later was 99.2%, and it remained >98.6% for 6 h. Rapid blood clearance of [(99m)Tc]-DTPA-DG was observed in in vivo biodistribution, the main route of clearance was via the kidneys. No significant accumulation in any other organs was seen. The tumor-to-brain and tumor-to-muscle concentration ratios for [(99m)Tc]-DTPA-DG uptake were higher than those for fluorine-18-flurodeoxyglucose ((18)F-FDG). Scintigraphic results demonstrated the feasibility of [(99m)Tc]-DTPA-DG imaging tumors. The [(99m)Tc]-DTPA-DG complex is a potential imaging agent due to the ideal physical characteristics of the radionuclide, ease of preparation, low cost, early accumulation and the preference for the renal route of excretion.