The Food and Drug Administration (FDA) has recently addressed known shortages of Technetium 99m (Tc-99m), an essential radioisotope used routinely for imaging a variety of conditions and anatomic sites, including several types of cancers, the heart, and the brain. The current shortage of Tc99m is the result of the May 2009 shutdown of the only North American producer of molybdenum-99, which is used to manufacture Tc-99m. Although other nuclear reactors have begun producing molybdenum-99, Tc-99m supplies are likely to be in short supply for several months, if not years.
During the Tc-99m radiopharmaceutical shortage, the FDA recommends that nuclear medicine healthcare providers try to maximize use of available Tc-99m, consider prioritizing clinical diagnostic tests that use Tc-99m, and also consider alternative diagnostic procedures. These recommendations include the following:
- Prioritize the use of the available Tc-99m to support the most clinically important tests. The importance of a diagnostic test depends on the individual patient and facility needs, the required urgency of the test, and the availability of acceptable alternative tests.
- When scheduling tests, take into consideration the radioactive decay properties of the material used to generate Tc-99m in order to optimize Tc-99m yield. For example, schedule tests throughout the week (to include weekends) to most efficiently use available Tc-99m supplies.
- Inform patients who are scheduled for a nuclear medicine test should be aware that their appointments for tests requiring Tc-99m may need to be rescheduled. Consider alternative diagnostic studies when feasible and available. For example, approximately 60% of studies that rely on Tc-99m are used in heart-related procedures, which is a situation where several alternatives may exist. Possible alternative diagnostic tests to consider include the following:
- For coronary artery disease: Thallium-201 gamma scintigraphy, Rubidium-82 positron emission tomography (PET)/computed tomography (CT), Ammonia N-13 PET/CT, echocardiographic stress, or electrocardiographic stress tests.
- For suspected bone lesions: 18F-Fluorodeoxyglucose PET/CT, Sodium fluoride-18 PET/CT, computerized tomography, or magnetic resonance imaging.
- For pulmonary emboli: computerized tomographic angiography.
Additional information, including procedure guidelines and potential radiopharmaceutical alternatives for consideration, are available at:
Society of Nuclear Medicine: http://interactive.snm.org/
American Society of Nuclear Cardiology: http://www.asnc.org/index.cfm