Medical isotopes possible without a nuclear reactor

VANCOUVER—Canadian scientists say they have developed a technique to produce medical isotopes in hospitals and clinics without the need for a nuclear reactor.

The announcement, on the final day of the American Association for the Advancement of Science’s annual meeting in Vancouver, could signal the end to a crisis that has shaken up the medical community, politicians in Ottawa, and patients throughout Canada.

Two ageing nuclear reactors produce about 75 per cent of the global supply of medical isotopes. One of them, the reactor in Chalk River, Ont., about 180 kilometres north of Ottawa, produces 40 per cent of the supply of the raw materials needed to produce the isotopes.

But the era of dependency on nuclear reactors in the production of isotopes is over, said Tom Ruth, senior scientist at TRIUMF, the national laboratory for particle and nuclear physics based in Vancouver.

“It’s clearly a financial issue with the government as they don’t want to invest more money into the existing reactor (at Chalk River),” he said Monday.

By upgrading equipment already stored in a dozen hospital basements across Canada, the scientists say they can manufacture the isotopes with out the nuclear component.

The reactor previously produced about half the North American supply of molybdenum-99, which decays into the technetium-99m isotope used in the majority of nuclear medicine procedures like diagnostic imaging and cancer treatments.

Chalk River produced the molybdenum-99 and shipped it to two processing centres in the United States, which then shipped the finished isotopes back to Canada.

But the Chalk River reactor faces full shutdown in 2016, and the U.S. has also told Canada it will decrease or stop exporting the highly-enriched uranium by 2019.

The process of developing the medical isotopes through a particle accelerator known as a cyclotron has been done for four decades but not on a commercial scale.

Adjustments made to the cyclotron now enables scientists to write a recipe to produce the finished isotopes which will make it no longer necessary to ship the raw materials to the U.S.

“We have now successfully performed this process at the commercial scale,” said Paul Schaffer, head of nuclear medicine at TRIUMF.

“We’ve delivered a proof of concept.”

There are 18 cyclotrons in Canada in 12 facilities — six in Vancouver and two each in Hamilton, Toronto and Montreal. Over the next few years, another seven new cyclotrons are planned to come online throughout the country.

Schaffer said there are still regulatory hurdles that must be met through Health Canada. Several industrial partners and regional health authorities across the country are now starting to talk about how to fund and implement the commercial production of medical isotopes.

B.C. Cancer Agency researcher François Bernard said it was previously thought that it would be too costly to produce the isotopes outside of a nuclear reactor but the new process has challenged that notion.

“We will be able to produce Canada’s needs,” he said.

“It’s essentially a win-win scenario for health care, because you end up removing your dependence on a single source of technetium-99m, but you also make other isotopes more widely available.”

Using only one cyclotron, the new method could produce a fresh supply for a large metropolitan area every day, Bernard said.

“For the price of one nuclear reactor, you can buy hundreds of cyclotrons, and by buying cyclotrons, not only do you make technetium available but you also make the other isotopes for PET imaging.”

With files from The Canadian Press