Canadian officials have again shut down a nuclear reactor that produces much of the world's radioactive isotopes used to diagnose cancer patients through medical imaging.
Patients in line for medical tests to diagnose cancer and heart ailments may have a longer wait as hospitals try to conserve a scarce supply of isotopes, doctors say.
The latest shutdown of an Atomic Energy of Canada Ltd (AECL) nuclear reactor at Chalk River, Ontario – which provides about half the global supply of isotopes used in medical imaging - is expected to last about a month as technicians repair a leak of heavy water.
Only a week's supply left
Government-owned AECL said it has enough medical isotopes for the coming week, but will unable to meet demand by the weekend.
The AECL said its NRU reactor was shut down last Thursday after a power outage. The leak was discovered shortly after that. The 52-year-old reactor was ordered closed by Canada's nuclear regulator in 2007 until mandated safety upgrades had been completed. The nearly month-long shutdown that resulted sparked a critical global shortage of medical isotopes used in the diagnosis and treatment of cancer and heart ailments, and only ended when Canada's Parliament voted to bypass the regulator's order.
Delay non-urgent tests
Another lengthy shortage will force hospitals to delay non-urgent tests, said Dr Karen Gulenchyn, a nuclear medicine expert who helped advise former Canadian health minister Tony Clement during the last isotope shortage in December 2007.
"It may mean that if you have an elective study booked ... that patient is going to be deferred and have to wait until the situation is resolved," she said. "I'm reasonably confident that for most patients, if they're having an acute problem, that problem is going to be dealt with - and the greater the acuity, the more likelihood it's going to be dealt with quickly and expeditiously."
Patients injected with isotopes
Radioactive isotopes are injected into patients so radiologists can pinpoint areas of higher radiation, and spot changes in the body so they can make more accurate diagnoses.
The president of the Ontario Association of Nuclear Medicine, Dr Chris O'Brien, said once the shortage hits next week hospitals may start using a different type of isotope that was used years ago. It is more technologically challenging but still works.
O'Brien said hospitals may also inject fewer isotopes into patients - meaning medical imaging will take longer - or postpone nuclear medicine tests that aren't deemed urgent. – (Sapa, May 2009)
A look at radiation exposure