27 August 2010
Shortage of medical isotopes at crisis point
by Kate Melville
Radioactive isotopes are used to perform tens of millions of medical scans and treatments every year, but scientists at this week's Meeting of the American Chemical Society said a global shortage of these materials will likely jeopardize patient care and drive-up health care costs.
"Although the public may not be fully aware, we are in the midst of a global shortage of medical and other isotopes," said Robert Atcher, director of the National Isotope Development Center (NIDC). "If we don't have access to the best isotopes for medical imaging, doctors may be forced to resort to tests that are less accurate, involve higher radiation doses, are more invasive, and more expensive." According to Atcher, the shortage is already forcing some doctors to reduce the number of imaging procedures that they order for patients.
As well as imaging, medical isotopes are used to diagnose and treat a variety of diseases. Isotopes injected into the body can enable doctors to determine whether the heart has adequate blood flow; cancer has spread to a patient's bones; and help diagnose gallbladder, kidney, and brain disorders.
Eight out of every 10 procedures require one specific isotope, technetium-99m, which has a half-life of only six hours. Thus, technetium-99m can't be stockpiled. It must be constantly made fresh, and distributed quickly to medical facilities.
Wolfgang Runde, from the Los Alamos National Laboratory in New Mexico, said that an unexpected shut down of a major isotope production facility in Chalk River, Ontario, Canada, in 2009 precipitated the shortage. The Chalk River facility produces 50 percent of the U.S. supply of the isotope used to make technetium-99m. He added that production problems occurred at other isotope facilities, compounding the problem. Remaining isotope suppliers have not been able to make-up for the resulting shortage.
"Shortage of this key medical isotope makes it more difficult to carry out important medical procedures, such as finding out whether cancer has spread to the bones," Atcher warned. "Doctors have been trying everything they can think of to meet the needs of patients, including the use of other less-than-ideal isotopes, but it has been a real struggle."
The United States is highly dependent on foreign suppliers of medical isotopes as only about 10 to 15 percent of the isotopes used in medicine are produced domestically. "The challenge we have is to produce enough materials to meet commercial needs as well as needs of the research community - from nuclear physics, to environmental research, to medical research - amid increasing demands and fewer isotope sources," Atcher said. "The long-term solution to this crisis remains to be seen."
Source: American Chemical Society