Technetium-99m: An Elusive Isotope
The world’s hospitals rely on technetium-99m for imaging, but the isotope is in short supply.
Close to 20 million times a year, U.S. patients are injected with technetium-99m, which is used in scans to detect a variety of serious medical conditions. The radioactive isotope produces clear images, and its short half-life—just six hours—jminimizes patients’ radiation exposure.
As Proto reported in its Winter 2008 issue, hospitals had been waiting for months for the repair and reopening of the nuclear reactor at Chalk River, Ontario, which had provided 30% to 40% of the world’s supply of technetium-99m. More than two years later, they’re still waiting. What’s worse, a Dutch reactor that also produces technetium-99m was closed in February for repairs expected to take six months. The two reactors supply the United States with more than 80% of its molybdenum-99, the radioactive parent of technetium-99m.
The world’s hospitals rely almost entirely on five aging reactors, “all about 50 years old,” says Michael M. Graham, immediate past president of SNM (formerly the Society of Nuclear Medicine). “It’s not surprising that the reactors have major maintenance problems.”
Covidien and Lantheus, the main manufacturers and distributors of the isotopes, have hustled to distribute 400-pound “generators” filled with molybdenum-99, which then breaks down into the crucial isotope, to hospitals around the world.
In moves still largely unnoticed by patients, hospitals have rescheduled tests, reduced dosages and substituted other isotopes—a “minor” compromise that produces a poorer image and exposes the patient to more radiation, says Graham.
To meet immediate demand, Covidien negotiated an agreement with the Polish Institute of Atomic Energy to supply as much as 10% of the world’s needs, and Lantheus gained FDA approval to provide the United States with molybdenum-99 produced at a Czech reactor. Other projects, meanwhile, aim to ensure a long-term supply: An international group plans to build a reactor in the Netherlands that will begin operation as early as 2016, and an Australian reactor is boosting production.
Efforts to establish a domestic supply in the next several years are afoot as well. In January, GE-Hitachi announced a $2.25 million Department of Energy award to produce as much as half of the U.S. demand for molybdenum-99 in existing commercial reactors. Also this year, the DOE awarded Babcock & Wilcox Technical Services Group $9 million to produce more than half of the nation’s needs in a yet-to-be-constructed reactor. And the University of Missouri plans to begin production of molybdenum-99 at its research reactor within three years.
U.S. hospitals are especially eager for a home supply, Graham says, because “if terrorists were to set off a dirty bomb, it would suddenly be very difficult to ship radioactive materials by air.”