The shortage of medical isotopes is leading Canadian doctors to turn to medical-scan alternatives that may not be the best approach, a specialist in nuclear medicine said Monday.

The Society of Nuclear Medicine is meeting in Toronto until Wednesday to discuss the worldwide shortage of medical isotopes to test patients with cancer, heart disease and other serious conditions, partly caused by a shutdown of the reactor at Chalk River, Ont., due to a heavy water leak, as well as advances in their field.

Society president Robert Atcher of the University of New Mexico told a news conference that there are four problems with turning to older scanning methods:

• Higher radiation doses for patients.
• Potentially less useful information.
• Higher costs in many cases.
• More invasive effects in some cases.

Overall, relying on alternatives means radiologists and nuclear medicine specialists are not providing the best service they can for patients, Atcher said.

The society said 91 per cent of the 375 doctors and nuclear medicine technicians in the U.S., who responded to an email survey this week said half of their activities had been affected by the isotope shortage, with 60 per cent postponing procedures and 31 per cent canceling some scans.

Late Monday, Health Canada announced that it has authorized Lantheus Medical Imaging of Boston, Mass., to use molybdenum 99 (Moly-99) produced by the Open Pool Australian Light-water (OPAL) reactor to make Tc-99m for diagnostic imaging in Canadian health-care facilities.

The agency's approval means that the Moly-99, the most commonly needed medical isotope, produced by the OPAL reactor is safe and effective for use by Canadian health-care providers.

"This is very good news for Canadian health care providers and patients," Health Minister Leona Aglukkaq said in a release.

Lantheus Medical Imaging expects to begin receiving Moly-99 from the OPAL reactor over the next few weeks.

The society's president-elect, Dr. Mike Graham, director of nuclear medicine at the University of Iowa, called the isotope shortage a "serious crisis" facing his profession.

Looking to Australia, Russia

The operators of a nuclear reactor in Australia are rushing to make up for the shortage of the molybdenum-99 isotope. The reactor could supply 10 per cent of world demand.

Still, Canada and the U.S. need to step up their regulatory process to use those isotopes when they become available, he added.

A research reactor at the University of Missouri could be converted to use a less enriched grade of uranium favoured by the U.S. government because of its lower proliferation danger, but Archer estimated it wouldn't be able to produce "useful quantities" of isotopes for at least five to seven years.

On Monday, MDS Nordion, which normally gets its entire supply of isotopes from Chalk River, signed a deal with the Karpov Institute in Russia. The institute is currently being refurbished with the aim of producing isotopes for the international market, said Jill Chitra, the company's vice-president of strategic technology.

The Karpov Institute won't be able to make more isotopes until next year, so it won't help the current shortage.

New adviser will guide minister

On Sunday, Health Canada announced Dr. Alexander McEwan, head of oncology at the University of Alberta, has been appointed as a special adviser to the health minister on medical isotopes.

In his role as an adviser, McEwan told reporters he will advise the minister on what Canada can do in the short term in looking for alternatives to medical isotopes, and maximizing their use.

McEwan has been a member of Health Canada's ad hoc group of experts on medical isotopes since 2007 and is a past president of the Society of Nuclear Medicine's board of directors.