Nuclear medicine services in 20 European countries, the U.S., and Canada are learning to cope with the potential daily disruptions in the normal supply of molybdenum-99 from the forced shutdown of the High Flux Reactor in Petten, the Netherlands.
The HFR is one of two main sources of Mo-99 in Europe and an important source for nuclear imaging facilities in the U.S. Its operator, the Nuclear Research and Consultancy Group, announced an extended shutdown of the facility when a small core reactor coolant leak was discovered during routine maintenance Aug. 15. Providers learned Oct. 15 that the reactor would not be ready to resume isotope production until mid-January 2009.
Mo-99 is the precursor isotope for the production of technetium-99m, a radionuclide used in about eight of 10 nuclear imaging procedures. The effects of the Petten shutdown have been amplified because the BR-2 reactor in Mol, Belgium, Europe’s other main source of Mo-99, was out of service in August for routine maintenance. The Institute des Radioéléments in Fleurus, Belgium, one of the two plants in Europe that process irradiated targets, had also discontinued operations for repairs.
Covidien, Cisbo, and GE Healthcare are the main providers of Tc-99m generators to nuclear medicine facilities in Europe. To compensate for the reduced supply, they have drawn heavily on excess Mo-99 from the NRU reactor at Chalk River in Ontario and the Safari-1 reactor in Pelindaba, South Africa.
Covidien, in Hazelwood, MO, supplies technetium generators using Mo-99 from the Petten reactor to U.S. hospitals and clinics. Normal deliveries to these facilities have also been disrupted.
The research reactors that can produce Mo-99 typically alternate in increments of several weeks between isotope production and services for nonmedical customers. This pattern has made adjustment to the Petten shutdown more difficult, sources said.
In a written statement, Covidien admitted that its ability to supply Tc-99m generators could fluctuate depending on the day of production and the availability of Mo-99 from global reactors. In an Oct. 20 letter, Nico Beukman, Covidien’s area vice president for Europe and South Africa, predicted the availability of technetium generators from his firm would range from 20% to 100% of normal supply for the weeks from Oct. 26 to Dec 7.
The shortage has varied from week to week and country to country, said Dr. Wolfram Knapp, president-elect of the European Association of Nuclear Medicine. An Oct. 15 survey of EANM delegates from 20 European countries found that nuclear imaging services in some countries were operating at 70% of normal, while hospitals in other countries had seen their daily allotments of Mo-99 cut in half.
Facility size has also had an influence. Percentage cuts in the deliveries to large facilities that normally receive large quantities of technetium generators are less disruptive than for services that usually get small consignments.
Many services have switched to thallium-201 for myocardial reststress imaging, said chair of the EANM radiopharmacy committee Clemens Decristoforo, Ph.D. Some are performing bone scans with fluorine- 18 sodium fluoride(Drug information on sodium fluoride), a radioisotope that was used for the task before the introduction of Tc-99m-MDP and other diphosphonate agents in the 1960s.
The European Medicines Agency (EMEA), European Union members, and local agencies have worked together to mitigate the supply problem, Decristoforo said. EMEA collaborated with French and Dutch officials to allow Mo-99 produced at the Osiris reactor at Saclay Centre near Paris to be processed at Petten while renovations at the French producers’ normal processing center at Fleurus, Belgium, were completed this fall.
European nuclear medicine officials are concerned that the Petten shutdown signals the beginning of chronic problems with Mo-99 supply on the continent. North America faced a similar crisis in December 2007 from the extended shutdown of the NRU reactor at Chalk River. The HFR at Petten and BR-2 reactor at Mol are both more than 40 years old, said Dr. A. Al Nahhas, EANM secretary.
Renovations that would allow Mo- 99 production at nuclear reactors in Poland, the Czech Republic, Romania, and Russia have been proposed.
"The most suitable measure will be to build a new reactor," Nahhas said. "But we think it will take ages until this happens."
—By James Brice
