Medical isotopes are used to find cancers that have spread and to diagnose heart problems. ((CBC))

Smaller hospitals in Canada could start cancelling diagnostic scans for cancer as early as Wednesday because of the shortage of medical isotopes, experts say.

Some Quebec hospitals are likely to cancel some scans on Wednesday, said Dr. Francois Lamoureux, head of Quebec's Association of Nuclear Medicine Specialists.

"What is going on at the moment at the federal level is incredible," said Lamoureux. "I'm saying it's not a political crisis. It's a medical crisis."

The supply of medical isotopes has dwindled since May 15, when a nuclear reactor at Chalk River, Ont., was shut down after inspectors detected a heavy-water leak.

"There is a marked reduction in availability of medical isotopes this Thursday and Friday, where the shipments that we were hoping would be coming in from South Africa and the Netherlands will not be arriving," said Dr. Christopher O'Brien, head of the Ontario Association of Nuclear Medicine.

"For some of our smaller hospitals, there will be absolutely no medical isotope availability Thursday and Friday of this week."

'Torture to wait'

Jennifer H., who has thyroid cancer that has spread to her lymph nodes, was treated with radioactive iodine at a hospital in Montreal. But the hospital doesn't know what will happen when she returns.

"We don't know yet," she said. "I hope if I do need more treatment, the isotopes are going to be available. Because it's just torture to wait. Cancer doesn't stop growing in your body just because Chalk River shuts down."

Natural Resources Minister Lisa Raitt, who is under fire from the opposition for referring to the isotope shortage as a "sexy" problem on a taped private conversation, has said a Dutch reactor has agreed to increase its supply of medical isotopes by at least 50 per cent, and a South African reactor is also increasing production.

The Dutch reactor is also leaking, however, and is scheduled to be out of service for four weeks starting in July.

With files from The Canadian Press