Medical Isotopes

This report explores the main reasons behind the unreliable supply of Technetium-99m (Tc-99m) in health-care systems and policy options to address the issue. Tc-99m is used in 85% of nuclear medicine diagnostic scans performed worldwide – around 30 million patient examinations every year. These scans allow diagnoses of diseases in many parts of the human body, including the skeleton, heart and circulatory system, and the brain. Medical isotopes are subject to radioactive decay and have to be delivered just-in-time through a complex supply chain. However, ageing production facilities and a lack of investment have made the supply of Tc-99m unreliable. This report analyses the use and substitutability of Tc-99m in health care, health-care provider payment mechanisms for scans, and the structure of the supply chain. It concludes that the main reasons for unreliable supply are that production is not economically viable and that the structure of the supply chain prevents producers from charging prices that reflect the full costs of production and supply.

This book is the product of a congressionally mandated study to examine the feasibility of eliminating the use of highly enriched uranium (HEU2) in reactor fuel, reactor targets, and medical isotope production facilities. The book focuses primarily on the use of HEU for the production of the medical isotope molybdenum-99 (Mo-99), whose decay product, technetium-99m3 (Tc-99m), is used in the majority of medical diagnostic imaging procedures in the United States, and secondarily on the use of HEU for research and test reactor fuel. The supply of Mo-99 in the U.S. is likely to be unreliable until newer production sources come online. The reliability of the current supply system is an important medical isotope concern; this book concludes that achieving a cost difference of less than 10 percent in facilities that will need to convert from HEU- to LEU-based Mo-99 production is much less important than is reliability of supply.

Radioisotopes are widely used in the medical field for imaging and therapy of diseases by themselves or by tagging with other molecules that have the potential to target diseased cells. In imaging protocol, the radioisotope, such as technetium-99m or indium-111, decays through ?-radiation emissions, which are located by a scintigraphic camera (SPECT or PET) in the form of 2/3D image formation of the diseased organ. The other kind of radioisotopes, such as Lutetium-177 or Actinium-225, are those that decay through ?/?-decay, which is due to its valuable linear energy transfer that is in clinical use to eliminate diseased cells. This book will cover valuable information about selected diagnostic and therapeutic radioisotopes along with localization mechanisms of radioisotopes directly or through nanoparticles at diseased cells.

The decay product of the medical isotope molybdenum-99 (Mo-99), technetium-99m (Tc-99m), and associated medical isotopes iodine-131 (I-131) and xenon-133 (Xe-133) are used worldwide for medical diagnostic imaging or therapy. The United States consumes about half of the world's supply of Mo-99, but there has been no domestic (i.e., U.S.-based) production of this isotope since the late 1980s. The United States imports Mo-99 for domestic use from Australia, Canada, Europe, and South Africa. Mo-99 and Tc-99m cannot be stockpiled for use because of their short half-lives. Consequently, they must be routinely produced and delivered to medical imaging centers. Almost all Mo-99 for medical use is produced by irradiating highly enriched uranium (HEU) targets in research reactors, several of which are over 50 years old and are approaching the end of their operating lives. Unanticipated and extended shutdowns of some of these old reactors have resulted in severe Mo-99 supply shortages in the United States and other countries. Some of these shortages have disrupted the delivery of medical care. Molybdenum-99 for Medical Imaging examines the production and utilization of Mo-99 and associated medical isotopes, and provides recommendations for medical use.

Participants of the July 17-18, 2017, symposium titled Opportunities and Approaches for Supplying Molybdenum-99 and Associated Medical Isotopes to Global Markets examined current trends in molybdenum-99 production, prospects for new global supplies, and technical, economic, regulatory, and other considerations for supplying molybdenum-99 to global markets. This publication summarizes the presentations and discussions from the symposium.

Radioactive isotopes and enriched stable isotopes are used widely in medicine, agriculture, industry, and science, where their application allows us to perform many tasks more accurately, more simply, less expensively, and more quickly than would otherwise be possible. Indeed, in many cases--for example, biological tracers--there is no alternative. In a stellar example of "technology transfer" that began before the term was popular, the Department of Energy (DOE) and its predecessors has supported the development and application of isotopes and their transfer to the private sector. The DOE is now at an important crossroads: Isotope production has suffered as support for DOE's laboratories has declined. In response to a DOE request, this book is an intensive examination of isotope production and availability, including the education and training of those who will be needed to sustain the flow of radioactive and stable materials from their sources to the laboratories and medical care facilities in which they are used. Chapters include an examination of enriched stable isotopes; reactor and accelerator-produced radionuclides; partnerships among industries, national laboratories, and universities; and national isotope policy.

After World War II, the US Atomic Energy Commission (AEC) began mass-producing radioisotopes, sending out nearly 64,000 shipments of radioactive materials to scientists and physicians by 1955. Even as the atomic bomb became the focus of Cold War anxiety, radioisotopes represented the government’s efforts to harness the power of the atom for peace—advancing medicine, domestic energy, and foreign relations. In Life Atomic, Angela N. H. Creager tells the story of how these radioisotopes, which were simultaneously scientific tools and political icons, transformed biomedicine and ecology. Government-produced radioisotopes provided physicians with new tools for diagnosis and therapy, specifically cancer therapy, and enabled biologists to trace molecular transformations. Yet the government’s attempt to present radioisotopes as marvelous dividends of the atomic age was undercut in the 1950s by the fallout debates, as scientists and citizens recognized the hazards of low-level radiation. Creager reveals that growing consciousness of the danger of radioactivity did not reduce the demand for radioisotopes at hospitals and laboratories, but it did change their popular representation from a therapeutic agent to an environmental poison. She then demonstrates how, by the late twentieth century, public fear of radioactivity overshadowed any appreciation of the positive consequences of the AEC’s provision of radioisotopes for research and medicine.