Reactor production of n.c.a grade 143Pr, 161Tb and 111Ag radionuclides for radionuclide therapy applications

Large scale radioisotope production of no-carrier-added (n.c.a) radionuclides from bulk amounts of neutron irradiated targets were evaluated in view of their potential applications in nuclear medicine. Three different radionuclides viz 143Pr (T1/2 13.57 d and Eβmax 0.937 MeV), 161Tb (t1/2 6.91 d, Eβmax 593.1keV, Eγ 74.6 keV (9.8%)) and 111Ag (t1/2 7.45 d, Eβmax 1.09 MeV, Eγ 245.4 keV (1.24%), 342.1 KeV (6.68%)) were investigated for production in n.c.a form by (n,γ) followed by beta decay route. The radiochemical separation of the nuclide of interest was performed by precipitation in case of 143Pr and 161Tb and an ion exchange chromatography for 111Ag. The separated n.c.a grade products were of high radionuclidic purity (>99.9%) and did not contain any detectable impurities. Logistics of regular production of these radionuclides, their quality control and the scope for production of these radiochemicals with high specific activity are discussed in this paper. (author)