Dutch reactor shuttered until Feb, long-term isotope supply level questioned
More nuclear reactors that can generate medical isotopes are key to stemming shortage. Image Source: Canada.com  
What started as temporary European shortage of radionuclides, caused by the closure of several nuclear reactors, could turn into a long-term medical imaging isotope shortage, because a Dutch radioisotope reactor will not reopen until February, according to the Nuclear Research and Consultancy Group (NRCG).

In late August, the High Flux Reactor at Petten in the Netherlands temporarily shut down when air bubbles were found in its cooling system. The closure coincided with planned maintenance at other European nuclear medicine reactors, such as the BR2 reactor in Belgium and the Osiris reactor in France, the Safari-1 reactor in South Africa and the large Chalk River plant in Ontario, Canada, tipping the scales toward a global isotope shortage.

The NRCG stated that the Petten reactor will now remain shuttered until Feb. 16 for safety reasons. One of the isotopes generated there is used in 80 percent of nuclear diagnostic procedures; the site also manufactures between 30 and 40 percent of the global radioisotope supply, according to Bloomberg.

Since early September, planned and unplanned shutdowns in five main reactors that produce medical isotopes have drastically cut the supply of technetium-99m (Tc-99m), the radioactive tracer generated from molybdenum-99 (Mo-99).

Hospitals affected by the shortage have been receiving on average around 60 percent of their normal supply of Tc-99m, causing them to ration diagnostic procedures that use the isotope, turn to alternative isotopes, such as thallium-201, that produce inferior images and expose patients to higher radiation doses, or avoid radioactive diagnostic imaging altogether.

The problems follow an unrelated incident last November, in which the Chalk River nuclear plant was closed for five weeks, causing radiopharmaceutical shortages in the United States.
As a result, the European Commission asked the European Medicines Agency (EMEA) to analyze the radiopharmaceutical shortage, in a bid to avert future problems.  EMEA has already approved the transport of nuclear material from the Osiris reactor in France to processing facilities at Petten to compensate for the closure of Fleurus, a Belgian production facility shut down because of a release of iodine-131. Collaborations with reactors in Canada and South Africa should also help to boost Europe's supplies, the agency said.

However, the current shortage is only a temporary, and supplies are expected to increase when Petten reopens in December, EMEA added.

For the time being, the industry is questioning how to solve the long-term issues, according to Guy Turquet de Beauregard, vice president of the Brussels-based Association of Imaging Producers and Equipment Suppliers. There are few reactors able to generate Mo-99 due to safety and security issues surrounding the use of uranium-235, which is irradiated to give Mo-99. Additionally, these reactors are close to 40 years old and further problems will occur as they get older, he noted.

Plans for a new reactor in Canada, which would have supplied the entire global demand of Mo-99, were scrapped in May this year due to design faults and legal disputes. While getting approval to build a new reactor is a lengthy and difficult process, demand for radiopharmaceuticals is fast increasing.

De Beauregard said suggestions for a solution include better international cooperation to monitor reactor maintenance schedules or upgrading existing reactors to produce Mo-99.