Changes needed to medical isotope production, scientist says

A research scientist at Canada's national particle and nuclear physics lab is calling on thefederal government to look into ways of delivering radioactive medical isotopes without the need for nuclear reactors.

Thomas Ruth, a chemistry adjunct professor at the Vancouver-based TRI-University Meson Facility (or TRIUMF), writing in the journal Nature on Wednesday, said the current system of delivering medical isotopes does not meet the demands of hospitals.

Medical isotopes give off energy that can be detected by imaging equipment and, when injected into a patient's body, can provide medical staff with a clearer picture of the processes at work. They have become part of the standard treatment for some cancers and help improve medical imaging.

Four-fifths of the most widely used radioactive isotopes comes from just two nuclear reactor facilities: one in the Netherlands, and one in Canada. Plant closures at these facilities in 2007 and last year led to shortages in the worldwide supply of medical isotopes, drawing public attention to the fragile nature of the industry. ButRuth says there are few projects in the works that might provide relief to aging facilities.

"There are no near-term or even long-term solutions being implemented that could provide a reliable and adequate supply for Europe and North America," he writes.

Ruth proposes two alternative methods he says the government should consider. One is particle accelerator technology, in which an accelerator would fire photons at a relatively stable uranium isotope, uranium 238. Ruth points out that while scientists have concluded that such accelerators could be built in principle, research to verify those conclusions needs to be completed before they could become a reality.

But he says the accelerators would involvefewer potential environmental or health risks than reactors.

PET scans an alternative

Ruth's other suggestion is a move away from scans reliant on reactor-made isotopes and toward positron emission tomography (PET) scans. PET scans use isotopes that can be created in hospital-run cyclotrons but have a shorter life than reactor-produced isotopes.

He said PET scanners and cyclotrons would have to come downin cost for this to be an attractive option, as less than 15 per cent of nuclear medicine installations in the U.S. are equipped with PET scanners.

Both proposals were first made in a report TRIUMF produced after a task force met in Vancouver in the fall of 2008 to discuss time lines and costs.

The report said construction of an accelerator would take three to four years and, depending on the technology used, would cost between $50 and $125 million to build.

In Tuesday's budget the federal government called for $351 million in funding to Atomic Energy of Canada Ltd. for its operations, including the development of the Advanced Candu Reactor.

But there was no mention of any money toward alternative means of producing medical isotopes.

"AECL has not bought into our proposal and would not voluntarily commit any of their resources to other projects," said Ruth.

The Chalk River facility was again in the news this week as opposition MPs grilled the government on Tuesday about two separate leaks at the AECL reactor.

The Nuclear Safety Commission issued a statement Wednesday saying that "at no time was the public or the environment at risk" and that no radioactive material leaked into the Ottawa River.