Synthesis and biological results of the technetium-99m-labeled 4-nitroimidazole for imaging tumor hypoxia

1-(4-Nitroimidazole-1-yl)-propanhydroxyiminoamide (N4IPA) was synthesized. The biodistribution of 99mTc-N4IPA in mice bearing S180 tumor demonstrated that the complex showed accumulation in tumor and slow clearance from it. The tumor-to-tissue uptake ratios increase with time. These results suggest that 99mTc-N4IPA would be a marker for imaging tumor hypoxia.