Isotope Routinely Available: Actinium-225

Actinium-225 (Ac-225, t1/2 = 10.0 days) is routinely available from the U.S. Department of Energy’s Isotope Program. Starting in February 2018, Ac-225 will be produced regularly via the proton bombardment of thorium-232 (Th-232) targets at our accelerator sites at Brookhaven (BNL) and Los Alamos National Laboratories (LANL). Ac-225 continues to be distributed as a thorium-229 (Th-229) decay product from Oak Ridge National Laboratory (ORNL) as well. The alpha-emitting radionuclide Ac-225 has attracted increased interest within the medical community for its alpha-radioimmunotherapy applications or its decay product bismuth-213 (Bi-213) from an Ac-225/Bi-213 generator.

The amount of Ac-225 available from the decay of Th-229 is limited due to the capacity of the Th-229 cows at ORNL. This capability can support quantities to meet the needs for basic science and pre-clinical research. The accelerator-based production of Ac-225 has the capability of producing hundreds of mCi per month required to support clinical trials, with scale-up to multi-Ci per month production in progress. Irradiations of Th-232 targets will occur at BNL and LANL with Ac-225 being separated and purified at ORNL. In 2018, accelerator-based production runs will be performed every other month with material available starting in February. The production frequency will be adjusted depending on community interest. The routine production and distribution of Ac-225 addresses a recommendation in the Nuclear Science Advisory Subcommittee on Isotopes (NSAC-I 2015) Long Range Plan.

Quotation requests for both accelerator-produced and Th-229-produced Ac-225 may be placed using the National Isotope Development Center’s (NIDC) online product catalog. For further inquiries about the availability of Ac-225, please contact Dr. Wolfgang Runde at runde@lanl.gov, Associate Director for Production Planning and Customer Relations, NIDC.