OTTAWA - The already shaky isotope supply may get a whole lot shakier.
A Dutch reactor stepping in for its downed counterpart at Chalk River, Ont., is scheduled for a month of maintenance starting this weekend -- but hospitals still don't know how the shutdown will affect their isotope shipments.
"We're holding our breath to see what will happen," said Dr. Christopher O'Brien, head of the Ontario Association of Nuclear Medicine.
"I assume towards the end of the week we may be getting information -- I would hope, let's put it that way -- because we all have to determine what to do as of Monday."
Isotope shipments are already erratic, he said. Supplies vary weekly so doctors have to wait to see how many isotopes they get before booking patients.
"You can't book anything ... until you get the notice probably Tuesday, Wednesday, which will allow us to know what to do Thursday, Friday," O'Brien said.
"Scheduling is terrible."
Further shortages could mean hospitals and clinics already coping with a scare supply of isotopes will bump some patients for others with more pressing ailments.
Five aging nuclear reactors supply the world with molybdenum-99, which is used to generate the radioactive isotope technetium for nuclear imaging.
Of those reactors, the Canadian and Dutch ones together produce about 70 per cent of the world's medical isotopes.
The Dutch reactor increased its output after Atomic Energy of Canada Ltd. shut down its Chalk River reactor in mid-May after finding it was leaking radioactive water.
AECL doesn't expect Chalk River back until at least the year's end.
But the Dutch reactor will be down from July 18 to Aug. 18 for repairs -- leaving much smaller reactors in Belgium and South Africa to make up the shortfall.
Combined, the Belgian and South African reactors account for less than a quarter of the world's isotopes.
Doctors worry their supply will dry up even more.
"It's walking into the unknown," said Dr. Jean-Luc Urbain, head of the Canadian Association of Nuclear Medicine.
Last week, Health Minister Leona Aglukkaq and Natural Resources Minister Lisa Raitt warned of "a period of more critical shortage during the month of August."
The warning came after medical products maker Covidien Ltd. -- which refines and sells raw isotopes to pharmaceutical companies and clinics -- told its customers to expect shortages in July and August.
The company also warned of "significant shortages" later this month and for three days in late August.
But any shortages may be short-lived.
Lantheus Medical Imaging, a Massachusetts-based company that supplies clinics with `generators' used in medical imaging, says it expects to receive isotopes from a fledgling Australian reactor starting next month.
Health Canada and the U.S. Food and Drug Administration have already approved the Australian reactor's isotopes as safe to use.
"We expect to receive some shipments from the over the next few weeks," Lantheus executive Cyrille Villeneuve said.
"They should ramp up their capacity over the next few months."
Villeneuve added the Belgian reactor should be able to match the output of its Dutch counterpart for the month it's down.
