Rhenium complexes in nuclear medicine

Radioactive isotopes of rhenium, Re-186 and Re-188, have been suggested as candidates for radioimmunotherapy because of their nuclear properties (ener getic beta particles and imageable gamma photons). Re-188 is produced using a W-188/Re-188 generator. Neutron irradiation of Re-185 is used for the pr eparation of Re-186. Rhenium and technetium complexes have similar physical properties, such as structure and lipophilicity, but some chemical propert ies are different. For example, the higher oxidation states of rhenium are more stable (reduced rhenium radiopharmaceuticals are prone to reoxidation to perrhenate) than those of technetium. Perrhenate is mostly reduced with tin(Il) chloride in the presence of a suitable ligand. Perrhenate colloids, complexes of rhenium with diphosphonates, disulfanylsuccinate, sulfanylace tate and glycinate, synthetic peptide RC-160, and antibody conjugates with rhenium are studied from the point of view of their synthesis, chemical pro perties and pharmacokinetic properties. Possible therapeutic applications o f individual complexes are indicated. A survey of labelled Re compounds for verified therapeutic applications is given.