U.S. hospitals rationing nuclear imaging tests

By Julie Steenhuysen

CHICAGO (Reuters) - A North American shortage of medical isotopes has forced many U.S. hospitals to begin rationing scores of diagnostic tests, and doctors said on Friday they see no quick solution.

Last month, Canadian health officials shut down a nuclear reactor in eastern Ontario that produces a third of the world's supply of medical isotopes, used in scans to check for an impending heart attack or see if cancer has spread.

Repairs of a leak of heavy water at the Chalk River reactor, first estimated to take a month, may now take three, and Canadian officials say they eventually may leave the isotope business altogether.

The Canadian plant is one of five aging reactors worldwide -- none located in the United States -- to produce molybdenum-99, the most commonly used medical isotope. The rapidly decaying substance has a shelf life of just 67 hours, making it impossible to stockpile.

"We are seeing a shortage," said Dr. Peter Conti of the University of Southern California in Los Angeles.

Conti said the university's three hospitals have begun rationing supplies, and they are not alone.

Conti said a prolonged shortage could threaten clinical trials for cancer drugs because patients may not be able to get needed scans on schedule, forcing them to drop out.

The Society of Nuclear Medicine said 91 percent of 375 members including doctors and nuclear medicine technicians at hospitals across the nation reported in an e-mail survey this week that they had been affected by the shortage, with 60 percent postponing procedures and 31 percent canceling some.