September 11, 2008

Thousands Face Delay in Medical Tests

By Liz Szabo

Thousands of patients in the USA may face delays in getting key medical tests because of a global shortage of radioactive tracers, which are used to perform bone scans and to assess blood flow to the heart, experts say.

The radiotracer in short supply, Mo-99, is mostly used to observe blood flow to the heart and in bone scans that assess the spread of cancer, says Robert Atcher, president of the Society of Nuclear Medicine.

Used in 80% of nuclear medicine procedures, the drug also is used to measure kidney function and to gauge whether cancers have spread to the lymph nodes during some breast cancer surgeries.

The impact on patients is "very serious," Atcher says.

About half of the 20 million nuclear medical scans performed in the USA each year are for urgent needs, he says.

In some cases, cancer patients may safely delay the tests for a few days or weeks. But others, such as those who have had heart attacks, may not be able to wait and may have to have more invasive procedures, such as angiograms, says Atcher of the Los Alamos National Laboratory in New Mexico.

The shortage stems from the shutdown of three of the world's six facilities that make radioisotopes, according to an article by the British Nuclear Medicine Society in the current British Medical Journal, or BMJ. Reactors in France and Belgium have closed for scheduled maintenance, while a Dutch reactor unexpectedly shut down in late August because of a problem in its cooling system. The Dutch reactor, which supplies about half of the USA's supply of Mo-99, isn't expected to reopen until late October.

Mo-99 has a half-life of less than three days, so it can't be stockpiled or stored for very long. Half-life is the time required for a radioactive substance to lose 50% of its activity by decay.

The shutdown of a Canadian reactor in November and December last year delayed exams for about 50,000 patients in the USA, which has no facilities to make Mo-99, according to the BMJ article written by Alan Perkins, Andrew Hilson and John Hall.

All the reactors that make nuclear medicines are about 40 years old, the article states. As the reactors age, shortages could become more common. (c) Copyright 2008 USA TODAY, a division of Gannett Co. Inc. <>