Isotope shortage is limiting nuclear medicine across Europe

A worldwide shortage of medical isotopes used as radiotracers in molecular imaging will persist at least until the end of September, limiting European hospitals to between 20% and 40% of their usual nuclear medicine activities, the European Association of Nuclear Medicine warned this week.

Wolfram Knapp, the association’s president elect, said that with three of the five global nuclear reactors supplying medical isotopes still shut down, it is too early to determine when supplies will return to normal. But he cautioned: “The end of September is a best case scenario.”

In the meantime drug companies will have to ration deliveries of isotopes. Most hospitals receive isotope deliveries once a week, Dr Knapp said, but deliveries around Europe this week were generally about half of the normal quantities, and levels next week are expected to be even lower.

Although 80% of molecular imaging investigations are not urgent and can be postponed by one to three weeks, others must be done within days, and these cases will be at the top of the priority list, said Dr Knapp, who is director of nuclear medicine at the University of Hanover Medical School in Germany.

Alan Perkins, honorary secretary of the British Nuclear Medicine Society and professor of medical physics at University Hospital Nottingham, said that in some non-urgent cases doctors will have the option to use alternative tracers or alternative imaging methods, such as magnetic resonance tomography. “But some patients will receive suboptimal diagnostic observation,” he said. “It will slow up the system.”

Liselotte Højgaard, director of clinical physiology, nuclear medicine, and positron emission tomography at University Hospital, Copenhagen, said that supplies of medical isotopes at her hospital this week were 50% of normal but will drop to 16% of normal next week.

The hospital is one of the most active in nuclear medicine in northern Europe, with 30 000 investigations each year. Because of the isotope shortage she has cancelled plans to attend a conference this weekend so as to be involved in deliberations over which patients should be at the top of the priority list for nuclear medicine.

While describing the current situation as more of a discomfort than a crisis for patients, she said it was placing a strain on hospital staff wanting to provide optimal health care. “It is a hell of a job for us,” she said. “It is a bit like having a restaurant without enough food.”

If isotope supplies do not return to normal by late September, as expected, then the situation “will be much more serious,” she said.

The main cause of the isotope shortage was the unexpected shutdown at the High Flux Reactor in Petten, in the Netherlands, after gas bubbles were discovered escaping from a pipe into the primary cooling system in late August. The Petten reactor is the second largest global producer of molybdenum-99, normally providing more than 25% of global demand and more than half of Europe’s demand. Dr Knapp said that although molybdenum-99 accounts for around 90% of the isotopes used in nuclear medicine it has a half life of only 66 hours, making stockpiling impossible.

Two other reactors that supply molybdenum-99, one in France and one in Belgium, are closed down for regular maintenance, leaving two reactors to make up the shortfall. One is the National Research Universal reactor in Chalk River, Canada, the world’s largest supplier of molybdenum-99, covering about 50% of global demand, while the other is in South Africa. The Canadian reactor was shut down for five weeks last year because of safety concerns, causing shortages.

The current shortage is not confined to Europe. Robert Atcher, president of the Society of Nuclear Medicine and team leader of emerging medical technology at the Los Alamos National Laboratory in New Mexico, said in a statement after news of the Dutch reactor shutdown: “The United States and other countries are not prepared to adequately deal with the current situation—let alone anticipate other situations as they continue to arise.”

The European Association of Nuclear Medicine’s Dr Knapp said that new production capacity for medical isotopes is needed to avoid future shortages, with the best solution being a new reactor dedicated to production of isotopes for medical uses. The current large reactors that produce isotopes are over 40 years old and do not focus on producing medical isotopes.