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 99mTc. A one-step [99mTc]–DTPA–DG kit was prepared using the stannous chloride reduction method. When 99mTcO4− 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 [99mTc]–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 [99mTc]–DTPA–DG uptake were higher than those for fluorine-18-flurodeoxyglucose (18F–FDG). Scintigraphic results demonstrated the feasibility of [99mTc]–DTPA–DG imaging tumors. The [99mTc]–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.