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

Abstract

The development of novel specific radiolabeled probes as targeted imaging agents for a more accurate detection of cancer has gained considerable interest. Glucose analogue 18F-FDG is used worldwide for imaging of several cancer types. New glucose analogs radiolabeled with 99mTc could be a less-expensive and more accessible alternative for diagnosis using SPECT imaging. The complex of glucosamine and 99mTc were prepared, and its biodistribution was evaluated in solid Ehrlich carcinoma bearing mice. 99mTc-glucosamine was synthesized and radiolabeled with 99mTc with high yield and stability. Biodistribution studies showed that tumor uptake of 99mTc-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. 99mTc-glucosamine was rapidly removed from blood through the urinary system, so high amount of activity accumulated in kidneys. High uptake of 99mTc-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 99mTc-glucosamine was only at 5 min after intravenous administration, but later the most part of activity was removed. In conclusion, we suggested that 99mTc-glucosamine would be a promising candidate for cancer SPECT imaging.