Research Profile – Cyclotron Solution
A new method of producing medical isotopes may help prevent future shortages.
Dr. François Bénard
At a Glance
Who – Dr. François Bénard, professor of radiology, University of British Columbia (UBC).
Issue – Many diagnostic procedures require the medical isotope technetium-99m (Tc-99m). Unfortunately, the world relies on a handful of aging nuclear reactors to produce Tc-99m.
Approach – Dr. Bénard and his colleagues developed a method for producing Tc-99m on a cyclotron – a type of particle accelerator found in many hospitals.
Impact – A reliable, alternative method of Tc-99m production could help prevent future medical isotope shortages.
In 2009, a temporary shutdown at the nuclear reactor in Chalk River, Ontario, highlighted a major vulnerability in the world's medical isotope supply. The shutdown led to a worldwide shortage of the radioactive isotope technetium-99m (Tc-99m), creating significant delays in patients receiving badly needed medical imaging. But Canadian researchers stepped up to address the problem.
Tc-99m is needed for specialized medical scans that generate three-dimensional images of certain biological processes inside the body. Physicians use the isotope to identify certain types of cancer, do bone scans, look at heart function and blood flow, diagnose dementia, and more.
The world relies on a handful of aging nuclear reactors, including the one in Chalk River, to produce Tc-99m. The 2009 shutdown prompted the Government of Canada and the Canadian Institutes of Health Research to reach out to the health research community for alternatives. Dr. François Bénard, professor of radiology at the University of British Columbia (UBC), answered that call.
"When the isotope shortage occurred, I remembered an old paper I had seen back in the 1990s where researchers in the US had used a cyclotron to make an isotope that was similar to Tc-99m. So, I contacted colleagues at TRIUMF to see if they were interested in developing a research project to explore the feasibility of using the cyclotron," says Dr. Bénard.
Vancouver's TRIUMF is home to the world's largest cyclotron – a type of particle accelerator used to both study and produce subatomic particles. It is located next to the UBC campus. Working with researchers from four Canadian universities (UBC, University of Alberta, University of Sherbrooke and Western University), Dr. Bénard found that cyclotrons could indeed be adapted and used to produce Tc-99m.
A huge advantage of this technology is that there are already a number of cyclotrons in use across Canada. Many are located in hospitals and research labs where they are used to produce other types of isotopes for medical imaging. They are much smaller than TRIUMF, but they can be adapted to produce Tc-99m.
"About eight to ten cyclotrons in Canada can be retrofitted to make it possible for them to produce Tc-99m," says Dr. Bénard. Once this is done, some of the demand in the country for Tc-99m can be met.
"It won't meet the total demand, but the use of cyclotrons can reduce reliance on nuclear reactor–produced isotopes significantly. The building of several new cyclotrons is now planned in Canada, with the capability to produce Tc-99m. They will also be used to make other types of isotopes."
Hundreds more cyclotrons could be retrofitted around the world, alleviating shortages in other countries.
Since the TRIUMF discovery, cyclotrons in Vancouver, Hamilton, London, Edmonton and Sherbrooke have received upgrades to enable Tc-99m production.
"When the isotope shortage occurred, I remembered an old paper I had seen back in the 1990s where researchers in the US had used a cyclotron to make an isotope that was similar to Tc-99m. So, I contacted colleagues at TRIUMF to see if they were interested in developing a research project to explore the feasibility of using the cyclotron."
– Dr. François Bénard, University of British Columbia