Day 7: Medical scans threatened by anti-nuke fears?
Doctors are sounding the alarm about a shortage of radioactive materials used to guide surgery and examine medical conditions like heart disease and cancer.
The shortage is fallout from worldwide efforts to restrict the production of nuclear bombs. As more reactors are abandoned around the globe in anti-proliferation efforts, supplies for medical radionuclides are also drying up. But one Canadian doctor says he knows how to keep imaging people’s ailments without making new material for nuclear war.
Thomas Ruth is a research scientist at TRIUMF, Canada’s National Laboratory for Particle and Nuclear Physics, and a senior scientist at the British Columbia Cancer Agency. Both institutions are in Vancouver.
Ruth has an essay in this week’s issue of the journal Nature, in which he calls the problem of radionuclides “critical.”
“In 2007, the unanticipated closure of a single nuclear-reactor facility in Canada slashed isotope stocks in North American hospitals by about 80 percent, causing much panic and the cancellation of 50,000 medical procedures over five weeks,” he writes. “Some patients went into surgery without the scans their doctors usually rely on.”
And the prognosis is not optimistic, he adds:
Four-fifths of the most widely-used radionuclide comes from just two nuclear reactor facilities: one in the Netherlands, and one in Canada. Stockpiling for more than a couple of days is impossible, thanks to the short half-life of the isotope. Unexpected closures of both of these aging facilities over the past year and a half have caused panic and the cancellation of medical procedures. And both facilities make use of highly enriched uranium, which some see as a terrorism risk.
Last month Edwin Lyman, a senior scientist with the Union of Concerned Scientists in Washington, made the case in the Bulletin of the Atomic Scientists that producing medical radionuclides in the United States — safely out of the reach of terrorists — should be a national priority.
Ruth’s proposed solution is to replace reactor-made isotopes with ones made from an accelerator — though, perhaps naturally, he feels Canada ought to take the lead:
This is cheaper and safer, as it does not involve highly enriched uranium, but requires the Canadian government to take steps to retain its role as a world leader in nuclear medicine. His vision for the future involves equipping more hospitals with their own accelerator facilities, so that different isotopes can be used to produce clearer, better medical images.
In an email, Ruth explained that radionuclide imaging techniques, like PET and SPECT scans, complement magnetic techniques like MRI and CT scans. The latter methods can detect a defect, but are not able to describe it. Radionuclide imaging, also called “functional imaging,” can tell doctors exactly what they’re dealing with.
“For example, a lump may be detected by MRI or CT but it may not be possible to determine whether it is an aggressive tumor or benign,” Ruth said. “Functional imaging has a high probability of differentiating this.”
He said today’s PET and SPECT cameras are often combined with CT scanners, so that both types of images are generated at the same time. Across the globe, about 70,000 diagnostic images are taken each day, Ruth notes, to find tumours, monitor heart function following attacks, map blood flow though the brain, and guide surgery.
Ruth’s full article appears here.