Medical isotope shortage concerns in US

Efforts to address a shortage of medical isotopes are gaining momentum in the US amid warnings from a key government advisory panel and congressional action. 

Around 50,000 medical procedures are performed every day in the US using isotopes produced abroad. These medical isotopes contain small quantities of radioactive substance used to image and treat disease. 

The difficulties with isotope supply began in May 2009, when the Canadian government closed its 52-year-old nuclear reactor in Chalk River, Ontario, for three months to conduct repairs. The shutdown was later extended to the first quarter of 2010. The problem became worse when the 48-year-old High Flux Reactor in the Netherlands closed for a month this summer for regular maintenance; it will be closed again for repair work in early 2010 for another six months. These two reactors are estimated to supply 60 per cent and 40 per cent of the medical isotopes used in the US respectively.

The US Department of Energy’s (DOE) isotope programme does not currently have any working facilities that can separate a broad range of stable and long-lived isotopes. Neither can it provide continuous access to many of these key isotopes because it relies on accelerators and reactors whose primary work is not isotope production. 

On 12 November, a subcommittee of the DOE’s Nuclear Science Advisory Committee released a report calling for two major new isotope production facilities to be built in the country - a dedicated electromagnetic isotope separation facility, and a variable-energy, high-current, multi-particle accelerator that can produce critical research isotopes. The estimated total cost of these facilities is $25 million (?15 million) and $40 million respectively.  

In its report, the panel also expresses concern about the supply of important medical isotopes like molybdenum-99, which isn’t produced in the US and  with a half-life of just 67 hours is impossible to stockpile. Technetium-99m, a radioactive tracer thatis the most widely used isotope in nuclear medicine, is generated from Mo-99.

’Recent disruptions in international supply demonstrate the vulnerability of the nation’s health care system in this area,’ the subcommittee concludes. The situation is complicated by the significant non-proliferation issues associated with the transport and use of the highly-enriched uranium used for Mo-99 production. 

Congressional attention

The issue has caught the attention of Congress. On 5 November, the US House of Representatives voted to pass a bill encouraging the production of isotopes in the US. The legislation would authorise $163 million in funding from 2010 through 2014 to establish a DOE programme that supports industry and universities in the domestic production of Mo-99 using low enriched uranium. It also aims to phase out the export of highly enriched uranium for the production of medical isotopes.

The bill’s sponsor, Rep. Edward Markey, expressed dismay that the US still allows nuclear weapons-grade highly enriched uranium to be exported to other countries for medical isotope production. ’This 1950s-era policy simply does not work in a post-9/11 world,’ he stated during House floor debate. 

The Senate’s Energy and Natural Resources Committee is now considering the legislation, and will convene a hearing on the matter on 3 December. The full Senate must approve the measure before it can be forwarded to President Obama for his signature.

The President appears receptive; a DOE funding bill Obama signed into law in October included $20 million to jump-start the domestic supply of medical isotopes without the use of highly enriched uranium. 

Rebecca Trager, US correspondent for Research Europe