A University of Alberta team says it has proven the isotopes can also be created in a device known as a cyclotron.
The researchers say it provides an image that is just as reliable as reactor-based isotopes.
Forty per cent of the world supply of medical imaging isotopes are produced at the Chalk River facility.
Technical problems forced the facility to close in 2009 for more than a year and doctors were forced to diagnose cancer and heart ailments with an erratic supply of isotopes.
Chalk River resumed operations last August but is scheduled to close by 2016.
The Conservative government ruled out building a new reactor and invited proposals to make the technetium-99m isotope without a reactor.
The Alberta team was able to produce viable quantities of high-quality technetium-99m using a 19-mega-electron-volt cyclotron, a circular particle accelerator, Sandy McEwan, a researcher with the University of Alberta and medical director with Alberta Health Services’ Cross Cancer Institute in Edmonton, said in a news release.
"This means there is now a potentially valid alternative to reactor-produced medical isotopes," he said.
A number of companies and researchers are also trying to develop ways to produce the isotopes. Efforts are underway separately in Saskatchewan, Manitoba and Quebec.