August 24, 2010
Isotope Shortage Could Jeopardize Care
Scientists fear that a global shortage of radioactive isotopes, required for the 20 million medical scans and treatments done each year, could jeopardize patient care and drive up health care costs.
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 or whether cancer has spread to a patient's bones. Isotopes help diagnose gallbladder, kidney, and brain disorders. When delivered into a malignant tumor, isotopes can kill the cancer cells while minimizing damage to nearby healthy tissue.
The shortage of radioactive isotopes also threatens basic and environmental research, oil exploration, and nuclear proliferation.
"Although the public may not be fully aware, we are in the midst of a global shortage of medical and other isotopes," Robert Atcher, Ph.D., MBA, director of the National Isotope Development Center (NIDC), the U.S. Department of Energy unit responsible for production of isotopes nationwide, was quoted as saying. "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."
The shortage already is forcing some doctors to reduce the number of imaging procedures they order for patients, Atcher added.
Each day more than 50,000 patients in the U.S. receive diagnostic and therapeutic procedures using medical isotopes, particularly individuals with heart problems and cancer. Eight out of every 10 procedures require the isotope technetium-99m, which has a half-life of only six hours. Thus, technetium-99m cannot be stockpiled. It must constantly be made fresh and distributed quickly to medical facilities.
Wolfgang Runde, Ph.D., who works with Atcher at the Los Alamos National Laboratory in New Mexico, was quoted as saying that an unexpected shutdown 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. Simultaneous production problems at other isotope facilities compounded the problem. Remaining suppliers have not been able to make up the resulting shortage, leaving the U.S. in an isotope supply crunch. The Chalk River facility, which was scheduled to restart this summer, remained closed as of early August.
"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," said Atcher. "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."
Atcher noted that the U.S. is highly dependent on foreign suppliers of medical isotopes. Only about 10 to15 percent of medical isotopes are produced domestically. The nuclear medicine community has been pressuring the U.S. government to develop improved domestic capability for producing these materials to reduce this dependence.
"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: Presented at the National Meeting of the American Chemical Society, Boston, August 22, 2010.