Separation and purification of 99mTc from 99Mo produced by electron linear accelerator

A quantitative description of the compatibility of technetium-selective chromatographic technetium-99m separation with low specific activity molybdenum-99

Technetium-99m generators employing a technetium-selective stationary phase are a chromatographic instrument developed for use with 99Mo having low specific activity (LSA); particularly, 99Mo produced by electron accelerators. This paper presents a mathematical description of technetium-selective chromatographic (TSC) 99mTc separation and analyzes its compatibility with LSA 99Mo. We developed a theoretical formula for TSC 99mTc separation by discretizing its pertechnetate selectivity, and validated it using an electron linear accelerator and activated carbon-based TSC (AC-TSC) 99mTc generators. We confirmed that the activity concentration of 99mTc obtained from a TSC 99mTc generator can be calculated directly from its input 99Mo activity regardless of the 99Mo specific activity. The formula corroborates that TSC 99mTc separation is compatible with LSA 99Mo, and has a practical application in estimating the number of TSC 99mTc generators required for 99mTc demand of interest.

New strategies for a sustainable 99mTc supply to meet increasing medical demands: Promising solutions for current problems

The continuing rapid expansion of ^99mTc diagnostic agents always calls for scaling up ^99mTc production to cover increasing clinical demand. Nevertheless, ^99mTc availability depends mainly on the fission-produced ⁹⁹Mo supply. This supply is seriously influenced during renewed emergency periods, such as the past ⁹⁹Mo production crisis or the current COVID-19 pandemic. Consequently, these interruptions have promoted the need for ^99mTc production through alternative strategies capable of providing clinical-grade ^99mTc with high purity. In the light of this context, this review illustrates diverse production routes that either have commercially been used or new strategies that offer potential solutions to promote a rapid production growth of ^99mTc. These techniques have been selected, highlighted, and evaluated to imply their impact on developing ^99mTc production. Furthermore, their advantages and limitations, current situation, and long-term perspective were also discussed. It appears that, on the one hand, careful attention needs to be devoted to enhancing the ⁹⁹Mo economy. It can be achieved by utilizing ⁹⁸Mo neutron activation in commercial nuclear power reactors and using accelerator-based ⁹⁹Mo production, especially the photonuclear transmutation strategy. On the other hand, more research efforts should be devoted to widening the utility of ⁹⁹Mo/^99mTc generators, which incorporate nanomaterial-based sorbents and promote their development, validation, and full automization in the near future. These strategies are expected to play a vital role in providing sufficient clinical-grade ^99mTc, resulting in a reasonable cost per patient dose.

Sorption Profile of Low Specific Activity 99Mo on Nanoceria-Based Sorbents for the Development of 99mTc Generators: Kinetics, Equilibrium, and Thermodynamic Studies

⁹⁹Mo/^99mTc generators play a significant role in supplying ^99mTc for diagnostic interventions in nuclear medicine. However, the applicability of using low specific activity (LSA) ⁹⁹Mo asks for sorbents with high sorption capacity. Herein, this study aims to evaluate the sorption behavior of LSA ⁹⁹Mo towards several CeO₂ nano-sorbents developed in our laboratory. These nanomaterials were prepared by wet chemical precipitation (CP) and hydrothermal (HT) approaches. Then, they were characterized using XRD, BET, FE-SEM, and zeta potential measurements. Additionally, we evaluated the sorption profile of carrier-added (CA) ⁹⁹Mo onto each material under different experimental parameters. These parameters include pH, initial concentration of molybdate solution, contact time, and temperature. Furthermore, the maximum sorption capacities were evaluated. The results reveal that out of the synthesized CeO₂ nanoparticles (NPs) materials, the sorption capacity of HT-1 and CP-2 reach 192 ± 10 and 184 ± 12 mg Mo·g^–1, respectively. For both materials, the sorption kinetics and isotherm data agree with the Elovich and Freundlich models, respectively. Moreover, the diffusion study demonstrates that the sorption processes can be described by pore diffusion (for HT-synthesis route 1) and film diffusion (for CP-synthesis route 2). Furthermore, the thermodynamic parameters indicate that the Mo sorption onto both materials is a spontaneous and endothermic process. Consequently, it appears that HT-1 and CP-2 have favorable sorption profiles and high sorption capacities for CA-⁹⁹Mo. Therefore, they are potential candidates for producing a ⁹⁹Mo/^99mTc radionuclide generator by using LSA ⁹⁹Mo.