Isotope shortage means a healthcare crisis

The abrupt shutdown of two aging nuclear reactors that produce a radioisotope widely used in medical imaging has forced physicians in the U.S. and abroad into a crisis, requiring them to postpone or cancel necessary scans for heart disease and cancer, or turn to alternative tests that are not as accurate, take longer and expose patients to higher doses of radiation.

Because of limits on testing produced by the shortage, some patients will undergo heart or cancer surgeries that could have been prevented by imaging, and others will miss needed surgeries because of the lack of testing, said Dr. Michael Graham of the University of Iowa, president of SNM, formerly the Society of Nuclear Medicine. "It's possible that some deaths could occur," he said.

Private companies and government agencies in the U.S. and Canada are looking at new sources of the radioisotope, including the possibility of building new reactors and modifying existing research reactors, but any long-term solution is at least two to three years in the future, experts agree.

The situation is complicated by efforts by the U.S. government, the sole provider of the uranium used in the reactors, to shift to low-enriched uranium from the high-enriched fuel that is now used. Government officials fear that terrorists theoretically could divert the high-enriched form to the construction of bombs.

The shortage "is one of the greatest threats to our profession of modern times," said radiologist Robert W. Atcher of the University of New Mexico, last year's president of SNM.

The focus of this shortage is a short-lived radioisotope that most patients have probably never heard of -- technetium-99m, the "m" standing for metastable. With a half-life of only six hours, the isotope allows physicians to examine bones and blood flow, among other things, then quickly disappears from the body, minimizing the dose of radiation received by the patient. Because of its short half-life, the isotope cannot be stockpiled and must be used within a day or two after it is produced.

Every day of the year, nearly 55,000 Americans and tens of thousands of patients in other countries undergo nuclear medicine tests -- such as checking for the spread of cancer to the bones or monitoring the flow of blood through the heart -- most of them using technetium-99m. The radioisotope is attached to chemicals that allow it to bind to specific sites in the body, where it emits gamma rays that can be used to produce an image of the area.