Nuclear medicine clinics could be operating at 25 percent capacity or less by the end of the week due to a shortage of Technetium-99m (Tc-99m), said Marcelo DiCarli, MD, the director of cardiac imaging and chief of nuclear medicine at Brigham and Women’s Hospital in Boston.
The shortage stems from three nuclear reactor shutdowns occurring simultaneously. The Society of Nuclear Medicine & Molecular Imaging issued an alert last week warning of the impending shortage, highlighting a facility in South Africa that has been out of service since late last year and a planned 11-day shutdown of another reactor in Australia that began Oct. 29.
But DiCarli said a third facility, in Belgium, was out of service for a couple of days last week before resuming operations. There are only six operating nuclear research reactors in the world that can create Molybdenum-99 (Mo-99)—the parent of Tc-99m—meaning half of them were shut down at the same time last week.
More than 80 percent of nuclear imaging procedures in the U.S. require Tc-99m, according to the FDA, and American patients use about half of the world’s supply of the radioisotope. The shutdowns in Belgium and South Africa hit the field of nuclear medicine particularly hard, DiCarli said, because they produce the highest volumes of Mo-99.
“The whole supply chain is disrupted,” said DiCarli, also a member of the American College of Cardiology Imaging Council. “Some labs get a big technetium generator that they’re using and some labs buy unit doses directly from commercial suppliers—and the commercial suppliers, they’re in bad shape just as we are in the hospitals.”
Cardiac imaging patients are relatively lucky in the context of this shortage, DiCarli said, because there are reasonable alternatives available. Thallium-based imaging yields similar diagnostic information as Tc-99m imaging but exposes the patient to a higher dose of radiation.
DiCarli expects thallium to be used most often as a replacement until more Tc-99m is available, while select sites could offer positron emission tomography (PET).
But in other areas of nuclear medicine, such as bone scans, there isn’t a practical substitute.
Even though the supply chain of Mo-99 is notoriously precarious, DiCarli said it’s not something clinicians have to think about often. That’s changed in the past couple of weeks.
“It’s become the main topic of conversation—how do we come up with plan B and plan C depending on how things change day to day,” he said. “Fortunately, knock on wood, I think we are potentially OK for most of the week. We’ll see what the day-to-day changes forecast for us for the later part of the week and early next week if things don’t get resolved. Eventually, everyone will feel the pinch.”
The FDA in February announced the approval of a system to manufacture Tc-99m in the U.S., although domestic production could still be years away. None of the six active reactors are located in North America.