Comparison of 'classic' 99mTc-DTPA, 99mTc(CO)3-DTPA and 99mTc(CO)2(NO)-DTPA

The conversion of a Tc-tricarbonyl complex to a Tc-dicarbonyl-nitrosyl complex using NO+ reagents offers a synthetic tool for preparing a novel class of 99mTc labeled compounds. The principle was demonstrated with DTPA as chelating ligand. The biodistribution of the novel 99mTc(CO)2(NO)-DTPA was compared with that of 99mTc(CO)3-DTPA and 'classic' 99mTc-DTPA.