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

Introduction: The shortage of reactor-produced molybdenum-99 (Mo-99, t(1/2),=66 h) has renewed interest in alternative production methods of its daughter isotope, technetium-99m ((99)mTc, t(1/2)=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 [Tc-99m]TcO4(-). Herein we describe the design, manufacture and optimization of a remotely operated module for the purification or sodium pertechnetate from a bulk solution of molybdate. Methods: The automated purification module was designed to separate [Tc-99m]TcO4- using either Dowex 1x8 or an Aqueous Biphasic Extraction Chromatography (ABEC) resin. Mo-100 composite targets were irradiated with 18.5 MeV protons for 10 mu A.h using an ASCI TR19 cyclotron. Once purified, the radiopharmaceutical quality of (TcO4-)-Tc-99m 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. Results: The separation processes are efficient (75% for Dowex, 90% for ABEC) and complete in less than 30 min. Overall, up to 2.1 GBq of Tc-99m was produced using the (100)(p,2n)Tc-99m transformation, processed using the separation module and subjected to a detailed chemical and radionuclidic analysis. Due to its expense and limited availability, (MoO42-)-Mo-100 was recovered in >90% yield using a precipitation/filtration/lyophilization approach. Conclusions: Na[Tc-99m]TcO4 was produced using a medical cyclotron, recovered using an automated purification module and found to exceed all established quality control parameters. (C) 2012 Elsevier Inc. All rights reserved.