Figure 2.
Common chelators for RIT radioisotopes. A. DTPA can form an octadentate coordination with three tertiary amine nitrogen donors and five oxygen donors from the carboxylic acid arms. B. DOTA chelates metals with four tertiary amine nitrogen donors and four oxygens from carboxylic acid, forming an octacoordinate metal complex. C. Macropa is an 18-membered macrocyclic ligand that has shown success for stable chelation of 225Ac and 227Th. D. CHX-A”-DTPA is a derivative of DTPA. E. TCMC is a derivative of DOTA with four primary amide pendant arms for stable chelation of 212Pb. F. TETA is a selective chelator of 64/67Cu. G. NOTA, and its derivative H. NETA is a hexadentate chelator that was utilized for radioisotopes such as 67Ga and 90Y, respectively.