Canada university claims 'viable replacement' for Tc-99m supply

A cyclotron at the University of Alberta, which may be capable of creating an important isotope used in medical imaging. Source: Rick Harp, CBC Edmonton

A team at the University of Alberta in Edmonton has reportedly made a breakthrough in the race to find a viable replacement for supply of technetium-99m (Tc-99m), a medical isotope produced by Canada’s Chalk River reactor. The research has shown that Tc-99m can be created by a cyclotron. 

Alexander Sandy McEwan, MD, a researcher with the University of Alberta and medical director with Alberta Health Services’ Cross Cancer Institute in Edmonton, said that the team has produced "viable quantities" of high-quality Tc-99m using a 19-mega-electron-volt cyclotron, a circular particle accelerator that propels charged particles using a constant magnetic field. McEwan recently presented results from the first human clinical trials at the annual conference of the Society for Nuclear Medicine and Molecular Imaging in Miami.

McEwan said in a press release that the clinical trials were performed to Good Clinical Practice (GCP) standards, a set of international quality standards set by the International Conference on Harmonization. 

“We have taken the technetium made in the cyclotron and shown that it behaves exactly the same as the technetium we get from the reactor,” he said. “We’ve shown that the quality of the technetium and the quality of the images is the exactly the same.”

This process may be moving toward a viable non-reactor-based technology to replacing the medical isotope stream currently produced by the aging Chalk River facility, where 40 percent of the world’s medical radioisotope supply is generated, according to the researchers. The balance of the world’s supply of these imaging isotopes comes from aging reactors in South Africa, France, Belgium and the Netherlands, installations that will soon need extensive upgrading or replacement.

Currently, Tc-99m is used in 85 percent of all nuclear medicine procedures globally every year.

“If it’s an 800-metre race, we’ve hit the 300-metre point,” said McEwan. “We’ve established a very clear plan. Following that plan, we have achieved the first two or three goals in that process. We’re confident that the next two goals will be easy.”