Australia is facing possibly its worst ever shortage of medical isotopes, meaning 10,000 people or more may miss out on vital diagnostic scans.
The isotope molybdenum-99 is crucial to the diagnosis of conditions such as cancer, heart disease, neurological disease, and skeletal, renal and digestive disorders. Uranium fission produces the isotope, which then decays into the commonly used imaging agent technetium-99m.
But now, a problem at Australia’s only nuclear reactor has stopped the extraction of molybdenum-99 after it is produced. The reactor itself is unaffected, but a valve fault in the facility that extracts the medical isotope is to blame.
As a result, the medical community only has around 31 per cent of its normal supply of the medical isotopes this week, and as many as 10,000 people may be missing out on vital scans, says nuclear medicine advisor Geoff Currie, at Charles Sturt University, Australia.
Supply is set to drop even lower next week as the last of Australia’s domestic supplies run out, he says.
Supplies of molybdenum-99 are precarious due to its relatively short half-life of 67 hours, meaning the isotope decays too quickly to be stored for a long period of time.
Once inside the body, technetium-99m emits gamma rays that are detectable, making it easy to create images of muscles, bones and other areas of interest.
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Without it, imaging for everything from suspected bone fractures to pre-surgery scans are being delayed.
For example, a patient diagnosed with breast cancer may be unable to have the scans necessary to show their surgeon which lymph nodes to closely examine to evaluate cancer spread, delaying the surgery by days or more, says Currie.
“Right now these hospital departments don’t know whether they will be able to operate next week or not,” he says. “So that creates a great deal of uncertainty and stress amongst the patients as well as the medical staff.”
A key driver of the shortage is that the malfunction occurred during a scheduled three-week shutdown of a South African reactor for maintenance. Molybdenum-99 is a scarce resource, with only five to 11 reactors producing it normally, and global supplies are tenuous.
The Australian facility produces enough to supply around one third of the world’s demand of the isotope, although it is almost entirely used domestically. Nevertheless, the shortage has begun to have ripple effects, creating a strain on other countries’ supplies as any excess is now being directed to Australia, says Currie.
In the meantime, ANSTO is in discussions with the South African facility to obtain more, although it will take time for the reactor to be running at full capacity. Molybdenum-99 has a half-life of around 66 hours, which allows it to be delivered to hospitals and sometimes other countries, where it decays into the usable technetium-99m.
It is likely to take at least two or three weeks for the country’s supply to return to normal although there is no clear timeline from ANSTO on the possible fix, possibly leading to longer delays.