Toronto’s University Health Network set to begin producing medical isotopes
February 21, 2012
Jayme Poisson
STAFF REPORTER
Toronto’s University Health Network has purchased the equipment needed to produce medical imaging isotopes, further reducing the city’s reliance on an aging nuclear reactor.
Later this year, a particle accelerator called a cyclotron will settle into its new home — a concrete bunker in the basement of Toronto General Hospital (TGH).
The network of four hospitals — TGH, Princess Margaret, Toronto Western and Toronto Rehabilitation Institute — hopes to have the project running by the fall. It will produce, among other things, technetium-99m, which is used in tens of millions of procedures around the world, from diagnostic imaging to cancer treatments.
On Monday, a group of Canadian scientists announced the successful production of technetium-99m on cyclotrons in Ontario and British Columbia.
Traditionally, the isotope has been produced using a nuclear reactor, which produces the raw material of molybdenum-99 that decays into technetium-99.
The cyclotrons allow individual hospitals to have greater control of how and when isotopes are used, said Ian McDermott, senior director of research facilities planning at UHN. Some isotopes produced for research or medical use, such as the oxygen15 isotope, have a very short half-life, he said.
“Inside of about 20 minutes, oxygen15 doesn’t exist,” said McDermott, adding it would be impossible to ship those isotopes quickly enough even from another part of the city.
“It’s that kind of new technology which is really cool. And that’s really where things are going to change significantly,” he said, adding there will also be research into new and better isotopes to improve diagnostic imaging.
Till now, two aging nuclear reactors have produced about 75 per cent of the global supply of isotopes. One, in Chalk River, 180 kilometres north of Ottawa, produces 40 per cent of the supply.
In 2009, North Americans faced a shortage of isotopes after a pinprick-sized leak in the reactor closed it down for more than a year, producing a crisis that shook the medical community and the political world.
The plant is facing closure in 2016, and without such alternatives, hospitals would have been forced to look as far abroad as South Africa or Poland — driving prices up, said Christopher O'Brien, president of the Ontario Association of Nuclear Medicine.
The cyclotron being built for UHN is funded through the Canada Foundation for Innovation and the Ontario Research Fund. The machine will be locked inside a bunker. Once the isotopes are produced they’ll go into a hot cell in a nearby laboratory.
The cost of the particle accelerator, including service, hot cells and supporting equipment, is $3.9 million. Building the lab and the vault will cost $3.7 million, said McDermott.
McDermott said having a cyclotron beneath a hospital is safe, and the risk of accidental activity is “very, very minimal.”
The bunker would ensure there’s no exposure and the material that’s worked with is “highly contained” in the hot cells and the laboratory, he said, adding that even if there was a spill the short half-life of many of the isotopes means they become harmless quickly.
The Centre for Addiction and Mental Health (CAMH) also has a cyclotron but does not use it to produce technetium-99m. There are two in Hamilton, including one at McMaster that will be making technetium-99m by next week.
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