“I remember in Geneva, two months ago, we said, ‘Be careful, because this very week there is a risk of shortage if there is any problem with one of the strong absorption’ – and that’s what happened,” recalls David Crunelle. , spokesperson for Nuclear Medicine Europe (NMEU), the industry association.
Because of their nature, it is impossible to store these radioactive materials—they last forever. Technetium-99m works as a radioactive tracer because, when it decays, it emits gamma rays with a photon energy of 140 KeV. This is “too good” to be detected using a gamma ray camera, says Cathy Cutler, chair of isotope research and production at Brookhaven National Laboratory in the US.
But technetium-99m has a very short half-life, only six hours or so. So radioisotope production facilities send to hospitals small generators containing molybdenum-99. These generators, sometimes called “moly cows,” produce the sought-after technetium-99m as the molybdenum-99 decays — just like a commercial portable technetium-99m machine, which expires after about two weeks, when the molybdenum-99 is depleted. something rotten.
Glenn Flux, head of radioisotope physics at London’s Royal Marsden Hospital and Institute of Cancer Research, says that what makes technetium-99m imaging different from, say, a CT or MRI scan, is that it reveals the condition of the patient’s organs or tumor. it works—for example by showing the flow of blood to the area in question.
“CT will show you if there’s a tumor, but technetium or other isotopes will tell you if it’s active or aggressive,” explains Flux.
The recent shortage of radioisotopes has put thousands of people out of work in the UK alone, estimates Stephen Harden, vice-president of medicine at the Royal College of Radiologists (RCR). Healthcare workers have taken steps to distribute the radioisotope remnants around the UK, to ensure that patients who need it most – for example, those with cancer – can still have access to their scans. “If there wasn’t a nationally coordinated plan, there would be large areas of the country that don’t have anything,” Harden says.
Crunelle and colleagues at NMEU continuously monitor the production of medical radioisotopes at the world’s largest facilities. They study the maintenance schedule in advance, and, therefore, the NMEU often advises reactor owners to push these days back a little—for example, to reduce the risk of multiple shutdowns occurring at the same time. NMEU workers use software, a kind of reactor maintenance calendar, that allows them to predict production. But sometimes the unexpected happens, like the pipe problem in Petten.
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