Still Short On Medical Isotopes

A longer-than-expected shutdown at a Canadian nuclear reactor is worsening a global shortage of isotopes for medical imaging procedures such as bone scans and blood-flow monitoring.

Atomic Energy of Canada has disclosed that its reactor in Chalk River, Ontario, will be out of commission until the first quarter of 2010. When the reactor was first shut down in May after a heavy-water leak, the agency anticipated only a three-month outage (C&EN, June 1, page 8).

The reactor produces about 50% of the world’s supply of molybdenum-99, the raw material for technetium-99m, a key isotope in medical imaging.

According to Covidien, a major imaging company, medical communities in the U.S. and Canada are most affected by the outage. In a letter to customers, John Collins, the firm’s vice president for U.S. operations, warned that the situation could get worse early next year when a reactor in the Netherlands goes down for six months of extensive maintenance.

A survey of hospitals and other imaging facilities released last week by the Society of Nuclear Medicine finds that more than 80% are affected by the ⁹⁹Mo shortage. Many imaging centers are postponing or even canceling procedures. Others are switching to an alternative imaging technique that involves thallous chloride.

At the same time, the imaging industry is looking for a longer-term solution. Reps. Edward J. Markey (D-Mass.) and Fred Upton (R-Mich.) recently introduced legislation to promote U.S. production of ⁹⁹Mo.