Atomic Energy of Canada Limited estimates the National Research Universal reactor at Chalk River will resume isotope production by the end of July. (Fred Chartrand/Canadian Press)

The shortage of medical isotopes led to a 22 per cent decrease in cardiac, bone and lung diagnostic tests, a new report shows.

The report released Wednesday by the Canadian Institute of Health Information found there were about 12,000 fewer exams conducted in October 2009 compared to October 2008.

The report was based on a survey of nuclear medicine sites that performed 75 per cent of tests in Canada between October 2008 and October 2009. The study was done in February.

Researchers looked at three periods of the year:

• February, three months before the reactor at Chalk River, Ont., shut down.
• August, when the Petten reactor in the Netherlands, another major source of the technetium medical isotope, shut down temporarily.
• October.

Between August 2008 and August 2009, the drop in tests ranged from 18 per cent for lung and bone exams to 25 per cent for cardiac tests.

Other factors may also have contributed to the decline, such as a change in how exams were ordered, the report's authors said.

Between October 2008 and October 2009, decreases ranged from 16 per cent for lung exams to 22 per cent for bone and cardiac tests.

About two-thirds of respondents said they experienced an increase in the cost of isotopes and that they were managing, but exceeding their budget due to vendor surcharges for isotopes from Europe and South Africa.

Shifting to another type of isotope for cardiac tests helped, as did changes to work schedules to take advantage of available isotopes on evenings and weekends, said Dr. Chris O'Brien of the Ontario Association of Nuclear Medicine.

"This has come at a cost to the health-care system, but at the same point, we've been able to respond to patients' needs fairly well," O'Brien said.

There has been no word from governments on reimbursing hospitals for those costs, which average about $50,000 for the year without considering overtime wages, he added.

Atomic Energy of Canada Limited said Wednesday that repairs to the National Research Universal reactor at Chalk River are 100 per cent complete. AECL applied to the Canadian Nuclear Safety Commission to hold a one-day public hearing to consider its application for the restart of the NRU reactor on June 28.

AECL estimates isotope production will resume by the end of July, and the first medical isotopes will start to be removed for processing and distribution within 10 days of the reactor being returned to service.