With the Canadian National Research Universal (NRU) reactor in Chalk River, Ontario, and High Flux Reactor (HFR) in Petten, the Netherlands resuming operations, the medical isotope supply is back to normal. "We have no domestic supply and if we are relying on aging reactors around the world, then the isotope supply is precarious," said Michael M. Graham, PhD, MD, immediate past president of SNM, in an interview.
Each year, more than 16 million people in the U.S. undergo procedures using technetium-99m (Tc-99m), a radiotracer derived from molybdenum-99 (Mo-99). Over the past year and a half, physicians and patients alike have had to cope with a severe isotope shortage due to an extended and unanticipated shutdown of the NRU reactor at Chalk River—a situation that has been exacerbated by repair work at the HFR at Petten in the Netherlands. Only five reactors in the world produce Mo-99, and the reactors in Canada and the Netherlands account for over half of global supply.
“Cardiology uses about 50 percent of Tc-99m in the U.S,” said Graham, a professor at department of radiology, University of Iowa in Iowa City. There have been discussions in the nuclear cardiology community regarding some of the newer systems with higher sensitivities that either cut the dose or cut imaging time in half, added Graham. “SNM is developing guidelines in collaboration with the American Society of Nuclear Cardiology to recognize the decreased doses of technetium,” he shared.
Iodine-131, used to treat thyroid disease, is another radioactive isotope which is back to normal levels. There was a “mild shortage” of iodine-131, and physicians were unable to get the usual liquid iodine-131, which could be stocked and used in treating patients anytime, Graham said.
Avoiding a future crisis
There have been some steps taken internationally to avoid a future medical isotope shortage. The Dutch are planning on building a new reactor, Pallas, scheduled to be operational in 2016. The Australians are going to become a significant player in global molybdenum market, noted Graham.
“Nationally there are at least three initiatives that are slowly moving forward but would benefit immensely from better funding and particularly from Rep. Markey’s American Isotope production bill,” said Graham. He said the three possibilities are the University of Missouri reactor, the GE/Hitachi collaboration and the Babcock & Wilcox /Covidien collaboration. The isotope bill would authorize the appropriation of $163 million to support initiatives to produce Mo-99, which could significantly reduce the time to complete the proposed projects.
Reps. Edward J. Markey, D-Mass., and Fred Upton, R-Mich., co-authored H.R. 3276, the American Medical Production Act of 2009, which will allow the production of Mo-99 in the U.S., and to condition and phase out the export of highly enriched uranium for the production of medical isotopes. The nuclear medicine community has urged Sen. Christopher S. "Kit" Bond, R-Mo., to lift a “ hold” on the isotope bill, and permit a vote by the U.S. Senate. The bill passed the U.S. House of Representatives by an overwhelming vote of 400-17.
“Sen. Bond is holding up the bill and it looks like we might have to wait till he retires from Congress. It’s unfortunate, but that’s actually the most likely way we are going to get to move forward,” said Graham. Bond's term expires when the new Congress comes in January.