Medical isotopes supply stabilizes. Source: Pacific Northwest National Laboratory

The FDA said that the shortage of medical imaging isotopes is over and no further supply issues are expected, following the reopening of the Canadian reactor.

Canada's National Research Universal reactor at Chalk River, Ontario, the major source of radioactive isotopes for imaging purposes in North America, was forced to reopen on Dec. 16 by the Canadian legislature. Atomic Energy of Canada (AECL), which operates the reactor, said a supply of radioactive molybdenum-99 will be available shortly.

The National Research Universal “reactor has operated safely for the past 50 years and is safer now than ever before,” David Torgerson, president of AECL’s research and technology division, said in a statement after the reactor was reopened.

Molybdenum-99 is the precursor of technetium-99m, the isotope used for nuclear medicine procedures as sentinel node biopsies in cancer surgery, bone scans and staging cancer patients. Technetium-99m generators, which last for about two weeks, are used to provide isotopes for about 14 million nuclear medicine procedures annually in the United States.

There is currently no U.S. producer of the isotopes.

The Belgian Institut National des Radioelements and the Nuclear Energy Corporation of South Africa also produce molybdenum-99 for technetium-99m generators and is supplied to the United States.