The shortage is related in part to the shutdown of a Canadian medical isotope reactor. The Canadian reactor produced a third of the world's supply of medical isotopes before it closed in May 2009 for repairs. It remained offline until this summer.
The Canadian reactor supplied more than a third of the world's supply of Molybdenum-99 (Mo-99) a medical isotope, whose decay product, Technetium-99m (Tc-99m), is used for such imaging procedures as diagnosing and detecting heart disease, and cancer. More than 20 million scans and treatments are conducted annually in the U.S. using that isotope.
Each day, more than 50,000 patients in the United States will receive diagnostic and therapeutic procedures using medical isotopes, particularly individuals with heart problems and cancer. Eight out of every 10 procedures require one specific isotope: technetium-99m, which has a "half-life" of only six hours.