Preparation and use of the 225Ac- 213Bi generator / 中华核医学与分子影像杂志

ABSTRACT

Objective:To develop radiopharmaceuticals for targeted alpha therapy (TAT), a simple and useful 225Ac- 213Bi generator was developed to provide a short half-life α-emitter 213Bi. Methods:DIPEX resin was used as the stationary phase of the generator, a Sep-Pak Alumina N Plus Light Cartridge column was utilized as the column to construct the generator, and hydrochloric acid was used as the eluent. The γ spectrometer was used to determine the purity of the eluted 213Bi and verify the method to measure the radioactivity of 225Ac and 213Bi by using radioisotope calibrators. The elution curves of the generator at various settings were analyzed to find the best elute and storage conditions. Results:Using commercial 225Ac, 100 mg DIPEX resin and a Sep-Pak Alumina N Plus Light Cartridge column, a 225Ac- 213Bi generator with a column volume of 0.35 ml was constructed, which could be eluted 213Bi with a syringe drenched with hydrochloric acid. The produced 213Bi was pure, and the measured half-life was (45.75±0.12) min, which was consistent with the theoretical value (45.6 min). CRC ? calibrators with setting numbers of #086 and #018 could measure the activity of 225Ac and 213Bi with the average errors of -2.6% and + 0.2% respectively. The eluent for the 225Ac- 213Bi generator was 2 mol/L hydrochloric acid, of which 320 μl was required only to get 90% elution yield. The generator was recommended to be stored directly in the eluent to avoid drying. Conclusion:The 225Ac- 213Bi generator can be constructed to obtain 213Bi for TAT.