Canada funds hunt for new isotope sources

Three projects to develop new supply sources for the key medical isotope technetium-99m (Tc-99m) have been selected to receive over C$21 million ($20 million) in funding under Canada's Isotope Technology Acceleration Program (ITAP).

ITAP was set up by the Canadian government to invest some C$25 million ($24.3 million) over four years to advance non-reactor-based technologies for Tc-99m supply and optimise the processes to help bring them to market. The three selected projects are to receive a total of C$21.45 million ($20.9 million), with the remaining C$3.55 million ($3.46 million) covering support costs for the program.

Two cyclotron projects, at the University of Alberta and the Triumf consortium in British Columbia, are to receive C$7 million ($6.8 million) each, while the Prairie Isotope Production Enterprise linear accelerator project in Manitoba will receive C$7.46 million ($7.26 million). The three projects have all shown promising results under an earlier Canadian government initiative to diversify sources of Tc-99m using cyclotron and linear accelerator technologies, the Non-reactor-based Isotope Supply Contribution Program (NISP).

According to Natural Resources Canada (NRCan), these projects have shown promising results including small-scale demonstration of Tc-99m production, but more work is required to bring the technologies to commercial-scale production and to meet regulatory requirements.

Tc-99m is the most widely used medical isotope, employed in about 80% of nuclear medicine diagnostic procedures. As the isotope itself has a very short half-life of only six hours, the longer-lived molybdenum-99 (Mo-99) is
used to generate Tc-99m at the point of treatment. Mo-99 is produced in a handful of research reactors around the world: the NRU facility at Canada's Chalk River Laboratories produces around 40% of world supply.

Mo-99 itself also has a relatively short half-life of 66 hours, so reliable, regular supplies of the isotope are essential. However, recent years have seen global shortages when several of the handful of ageing research reactors used to produce the isotope have been out of action, prompting interest in investigating alternative sources. Tc-99m can be produced directly in a cyclotron by bombarding a molybdenum-100 (Mo-100) target with a proton beam, while linear accelerators can be used to generate Mo-99 by bombarding a Mo-100 target with high-energy X-rays. Such methods are also seen as presenting non-proliferation benefits as they do not require the use of high-enriched uranium either for fuel or targets for isotope production, although  LEU reactor fuels and targets are increasingly being used in reactor-based Tc-99 production.

Researched and written
by World Nuclear News