An automated module for the separation and purification of cyclotron-produced 99mTcO4−

IntroductionThe shortage of reactor-produced molybdenum-99 (99Mo, t½=66 h) has renewed interest in alternative production methods of its daughter isotope, technetium-99m (99mTc, t½=6.02 h). While adsorption chromatography serves as a mechanism for selective elution of sodium pertechnetate from technetium generators, this method of purification is not sufficient for many alternative production methods. Several ion-separation/solid phase extraction chromatography methods are known, yet none have been demonstrated on cyclotron-produced [99mTc]TcO4−. Herein we describe the design, manufacture and optimization of a remotely operated module for the purification of sodium pertechnetate from a bulk solution of molybdate.MethodsThe automated purification module was designed to separate [99mTc]TcO4− using either Dowex 1x8 or an Aqueous Biphasic Extraction Chromatography (ABEC) resin. 100Mo composite targets were irradiated with 18.5 MeV protons for 10 μA·h using an ASCI TR19 cyclotron. Once purified, the radiopharmaceutical quality of 99mTcO4− isolated from each process (Dowex and/or ABEC) was established by assaying for molybdate breakthrough, alumina levels and, in the case of the Dowex approach, residual organics.ResultsThe separation processes are efficient (75% for Dowex, 90% for ABEC) and complete in less than 30 min. Overall, up to 2.1 GBq of 99mTc was produced using the 100Mo(p,2n)99mTc transformation, processed using the separation module and subjected to a detailed chemical and radionuclidic analysis. Due to its expense and limited availability, 100MoO42− was recovered in >90% yield using a precipitation/filtration/lyophilization approach.ConclusionsNa[99mTc]TcO4 was produced using a medical cyclotron, recovered using an automated purification module and found to exceed all established quality control parameters.