Tc 99 m Generator Development: Up-to-Date Tc99m Recovery Technologies for Increasing the Effectiveness of 99Mo Utilisation

Abstract EN

A review on the 99Mo sources available today and on the Tc99m generators developed up to date for increasing the effectiveness of 99Mo utilisation is performed in the format of detailed description of the features and technical performance of the technological groups of the 99Mo production and Tc99m recovery.

The latest results of the endeavour in this field are also surveyed in regard of the technical solution for overcoming the shortage of 99Mo supply.

The technological topics are grouped and discussed in a way to reflect the similarity in the technological process of each group.

The following groups are included in this review which are high specific activity 99Mo: the current issues of production, the efforts of more effective utilisation, and the high specific activity 99Mo-based Tc99m generator and Tc99m concentration units; low specific activity 99Mo: the 99Mo production based on neutron capture and accelerators and the direct production of Tc99m and the methods of increasing the specific activity of 99Mo using Szilard-Chalmers reaction and high electric power isotopic separator; up-to-date technologies of Tc99m recovery from low specific activity 99Mo: the solvent extraction-based Tc99m generator, the sublimation methods for 99Mo/Tc99m separation, the electrochemical method for Tc99m recovery, and the column chromatographic methods for Tc99m recovery.

Besides the traditional Tc99m-generator systems, the integrated Tc99m generator systems (99mTc generator column combined with postelution purification/concentration unit) are discussed with the format of process diagram and picture of real generator systems.

These systems are the technetium selective sorbent column-based generators, the high Mo-loading capacity column-based integrated Tc99m generator systems which include the saline-eluted generator systems, and the nonsaline aqueous and organic solvent eluent-eluted generator systems using high Mo-loading capacity molybdategel and recently developed sorbent columns.

Tc99m concentration methods used in the Tc99m recovery from low specific activity 99Mo are also discussed with detailed process diagrams which are surveyed in two groups for Tc99m concentration from the saline and nonsaline Tc99m-eluates.

The evaluation methods for the performance of Tc99m-recovery/concentration process and for the Tc99m-elution capability versus Mo-loading capacity of generator column produced using low specific activity 99Mo source are briefly reported.

Together with the theoretical aspects of Tc99m/99Mo and sorbent chemistry, these evaluation/assessment processes will be useful for any further development in the field of the Tc99m recovery and 99Mo/Tc99m generator production.