Radiolabeling, Preparation, and Bioevaluation of 99mTc-Azathioprine as a Potential Targeting Agent for Solid Tumor Imaging.

Azathioprine, an antitumor agent, was labeled with ^99mTc using stannous chloride dihydrate as a reducing agent. Factors such as the amounts of the reducing agent and substrate, pH, and reaction temperature and time were systematically studied to determine the optimum conditions, under which the 95% radiochemical yield was achieved. Biodistribution studies demonstrate the suitability of ^99mTc-azathioprine as a novel tracer for tumor imaging. It shows high selectivity to high-replicating solid tumors. [ABSTRACT FROM AUTHOR]