Preliminary biological evaluation of 99mTc-glucosamine as a potential radiotracer for tumor imaging

The development of novel specific radiolabeled probes as targeted imaging agents for a more accurate detection of cancer has gained considerable interest. Glucose analogue 18 F-FDG is used worldwide for imaging of several cancer types. New glucose analogs radiolabeled with 99m Tc could be a less-expensive and more accessible alternative for diagnosis using SPECT imaging. The complex of glucosamine and 99m Tc were prepared, and its biodistribution was evaluated in solid Ehrlich carcinoma bearing mice. 99m Tc-glucosamine was synthesized and radiolabeled with 99m Tc with high yield and stability. Biodistribution studies showed that tumor uptake of 99m Tc-glucosamine increased from 0.44±0.06 %ID/g at 5 min postinjection (p.i.) to 0.54±0.06 %ID/g and 0.64±0.07 %ID/g at 1 h and 3 h p.i., respectively. The tumor/blood and tumor/muscle ratios also increased with time and reached 1.02±0.12 and 1.88±0.20 at 3 h p.i. 99m Tc-glucosamine was rapidly removed from blood through the urinary system, so high amount of activity accumulated in kidneys. High uptake of 99m Tc-glucosamine was also observed in two high-energy-dependent organs, heart and liver. In other organs such as lungs, spleen, stomach, small intestine and brain high uptake of 99m Tc-glucosamine was only at 5 min after intravenous administration, but later the most part of activity was removed. In conclusion, we suggested that 99m Tc-glucosamine would be a promising candidate for cancer SPECT imaging.