Cyclotron could meet isotope needs

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A St. Albert scientist says he’s glad to hear that a machine he helped build could help supply all the isotopes Alberta needs to diagnose many forms of cancer.

University of Alberta scientists announced Monday that they had successfully built a particle accelerator that could produce enough isotopes to cover 1,000 diagnostic procedures a day – which is basically what Alberta needs on any given day.

St. Albert radiopharmaceutical consultant Doug Abrams worked on this project between 2008 and 2013, and said he was thrilled to hear that it was now up and running.

“I’m really happy they finished it off.”

The federal government funded this project back in 2010 after a shutdown at the Ontario Chalk River reactor caused a global shortage of technetium-99m, a medical isotope used in many procedures.

“These reactors were very old,” Abrams said, and there are now maybe five in the world still in operation (Chalk River is now closed, so there are now none in Canada).

Abrams and his team wanted to show that this isotope could be made using cyclotrons (particle accelerators which smash protons into atoms at ludicrous speeds to create new elements) so Alberta wouldn’t have to rely on these finicky reactors.

Technetium-99m is a by-product of the radioactive decay of molybdenum-99, which you get from spent nuclear fuel. Doctors use it as a tag to track substances or tumours in the body. About 70 per cent of all diagnostic radiopharmaceuticals are based on it, but it has such a short shelf life (you lose half of it every six hours) that has to be produced daily.

While you can get this stuff from special reactors, most of those require weapons-grade uranium, which the U.S. isn’t keen to give out, Abrams said. Cyclotrons can make technetium-99m without such complications.

Using their new cyclotron, the U of A team shot a two by seven centimetre strip of molybdenum foil that was roughly as thick as a human hair with protons charged with up to 22 mega electron-volts of energy, Abrams said. That’s a lot, but you need that much if you want to jam more protons into a nucleus.

After about six hours of this, the team took the foil, dissolved it in hydrogen peroxide, filtered out the technetium, and dropped it into an IV drip for use, said Jan Andersson, a radiochemistry specialist with the project. The team is now doing a clinical trial to confirm their isotopes work the same as conventionally produced ones.

The team has shown that their cyclotron can potentially produce three times more technetium-99m than the Edmonton region uses per day, or enough to supply the entire province, Andersson said. It’s the first time anyone has been able to supply a region with this isotope without using a nuclear reactor.

Andersson said he’s not sure if cyclotrons would entirely replace reactors as a source of technetium-99m, as this method is slightly more expensive, but predicted they could supply part of the industry’s demand for it.

John Wilson, manager of the U of A’s Medical Isotope and Cyclotron Facility (which houses this project), said in a press release that cyclotrons were cheaper and safer than nuclear reactors and didn’t produce nuclear waste. Cyclotrons can also produce other isotopes used for positron emission tomography (PET) scans, which are beginning to replace technetium as the go-to imaging technology.

Abrams said this research would ensure Canada had a stable supply of the isotopes that are used tens of thousands of times a day in North America. He congratulated the U of A team for finally getting this project off the ground.

A paper on the cyclotron project can be found in this month’s Nuclear Medicine and Biology.

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Kevin Ma

Kevin Ma joined the St. Albert Gazette in 2006. He writes about Sturgeon County, education, the environment, agriculture, science and aboriginal affairs. He also contributes features, photographs and video.