An electrochemical generator for the continual supply of Bi from Ac for use in targeted alpha therapy applications.

Bismuth-213 is a radionuclide of interest for targeted alpha therapy and is supplied via a radiochemical generator system through the decay of Ac. Radionuclide generators employ longer lived "parent" radionuclides to routinely supply shorter-lived "daughter" radionuclides. The traditional Ac/Bi radiochemical generator relies on an organic cation exchange resin where Ac binds to the resin and Bi is routinely eluted. These resins degrade when they absorb large doses of ionizing radiation (>1 × 10 Gy/mg), which has been observed when the loading activity of Ac exceeds 2.59*10 Bq (70 mCi). Herein we report the development of an electrochemical generator for the supply of Bi that has the potential to overcome this limitation. Bismuth-213 spontaneously electrodeposits onto nickel foils in 0.1 M hydrochloric acid at 70 °C. Using this method, we were able to plate an average of 73 ± 4 % of the Bi in solution and obtain a final Bi recovery of 65 ± 8 % in 0.1 M citrate pH 4.5 via reverse electrolysis using titanium as the cathode. The recovered Bi had an average radiochemical purity of >99.8 % and was successfully used to radiolabel DOTATATE with an average radiochemical yield of 85.1 % (not optimized).