ity to irradiate tumor volumes in the cellular range (i.e., 50–80 microns). Translation of alpha-particle emitters into the clinical domain has now been accomplished. This could not have occurred without advances in several areas of radiochemistry, including radionuclide production, separations chemistry, and labeling methods that circumvent the problem related to high radiation levels (i.e., radiolysis) generated by therapeutic levels of radionuclide (Zalutsky 2003). Targeted radionuclide therapy is discussed in further detail in Chapter 4.
In the pharmaceutical industry and in many clinical specialties—particularly oncology, cardiology, neurology, and psychiatry—there is a demand for new radiopharmaceuticals to advance our knowledge of human biochemistry and physiology and to improve the ability to diagnose and treat diseases. The committee reviewed the current state and trends in radiopharmaceutical research and development (R&D), which are discussed in the following two sections. The first section (6.3.1) summarizes five priority areas with broad public health impact where radiopharmaceuticals could serve as scientific and clinical tools leading to major breakthroughs in health care and basic understanding of human biology. The second section (6.3.2) describes technologies and methods currently being explored that could enable innovations in radiopharmaceutical development and advances in these five priority areas.
Cancer Biology and Targeted Radionuclide Therapy. Greater understanding of the abnormal biology of tumor cells will allow cancer treatments to be developed that target these features (rather than non-specifically targeting rapidly dividing cells, which is the approach of most chemotherapeutics). Research is needed to develop the following: radiopharmaceuticals that enable an understanding and characterization of abnormal cellular biology to predict the most effective therapy in a particular patient; labeled anti-cancer drugs to determine whether the drug targets the tumor; radiotherapeutic agents to deliver the radionuclide to the tumor; and diagnostic radiopharmaceuticals to monitor response to treatment (Webber 2005).
Neuroscience, Neurology and Psychiatry. A large fraction of the efforts in radiopharmaceutical chemistry over the past 30 years has been dedicated to understanding the relationship between brain chemistry, behavior, and disease. Although substantial progress has been made in many