Radiochemical processing of nuclear-reactor-produced radiolanthanides for medical applications

Several radiolanthanides find their application in nuclear medicine because of their favorable decay properties, the most important ones being 143Pr, 149Pm, 153Sm, 165Dy, 161Tb, 166Ho, 169Er, 170Tm and 177Lu. These radiolanthanides can be efficiently produced via neutron irradiation in a high-flux nuclear research reactor. Radiochemical processing of the irradiated target is required to obtain the required purity or to remove redundant target material. Long-lived impurities can be removed to extend the expiration time of carrier added radiolanthanides, whereas non-carrier added radiolanthanides with high radionuclidic purity and high specific activities can be obtained for targeted radiotherapy. Transport and distribution criteria might become more flexible, helping to safeguard the supply of radiolanthanides for medical purposes. Valuable and expensive target material can be regenerated after separation of the medical radiolanthanide. Different radiochemical separation processes are discussed which are able to separate two adjacent lanthanides, with a focus on those techniques making use of the underlying coordination chemistry.