Radionuclide Generators

Abstract

The present status and future directions of research and development on radionuclide generator technology are reported. The recent interest to develop double-neutron capture reactions for production of in vivo generators; neutron rich nuclides for radioimmunotherapeutic pharmaceuticals; and advances with ultrashort lived generators is highlighted. Emphasis is focused on: production of the parent radionuclide; the selection and the evaluation of support materials and eluents with respect to the resultant radiochemical yield of the daughter, and the breakthrough of the radionuclide parent; and, the uses of radionuclide generators in radiopharmaceutical chemistry, biomedical and industrial applications. The 62 Zn -62 Cu, ^Ni -""Cu, ,03m Rh -• ,03 Rh, ,88 W -• ,88 Re and the 225 Ac -22, Fr -2l3 Bi generators are predicted to be emphasized for future development.

Actinium-225 in Targeted Alpha-Particle Therapeutic Applications

“…The 229 Th breakthrough was effectively removed in a single separation cycle by changing the pH of the solution. This process takes advantage of the differences in the stability constants of thorium (K 1 = 10 13 , K 2 = 10 8 ) and actinium (K 1 ~ K 2 = 10 6 ) citrate complexes [22]. …”

Preparation of 166Dy/166Ho-EDTMP: a potential in vivo generator system for bone marrow ablation

“…These results were expected because, as explained above, the lanthanide elements exhibit uniform chemistry, therefore the change in the atomic number as a result of b -decay of the central lanthanide ion has minimal effects on the chemical binding [5]. Samarium, another lanthanide, forms a stable complex with EDTMP which localizes on the surface of cortical and trabecular bone.…”

“…The parent is attached to a tissue-specific therapeutic agent or vector and the daughter should decay with emission of energetic beta particles. After tissue target localization and production of the desired daughter radioisotope by decay, the target tissue would be exposed to a maximum radiation dose [4][5][6]. 166 Dy (T 1/2 = 81.5 h, E b -,av = 130 keV) can be produced by the neutron irradiation of 164 Dy and decays to 166 Ho, (T 1/2 = 26.6 h, E b -,av = 665.7 keV) as the daughter radionuclide.…”

Nuclear Separations for Radiopharmacy: The Need for Improved Separations To Meet Future Research and Clinical Demands

“…10 Given the numerous recent advances in separations chemistry, 23 the profitable manufacture of radionuclides by novel, patent-protected methods now appears quite feasible. The development of new radiopharmaceuticals will continue to require the collective efforts of the medical, biological, chemical, and nuclear communities, and a major aspect of these efforts will involve separation science.…”