Among the readily available -emitting radionuclides, the nuclides of iodine have the greatest versatility in labeling both the hydrophilic and the lipophilic compounds that are used in biology and medicine. Biologically important micrmolecules, semimacromolecules, and macromolecules have been identified which, after iodination, almost maintain the same molecular configuration and similar biologic specificity as those of the parent molecules. The multiple techniques for iodination and the clinical use of iodinated products have made possible the present status of the development of diagnostic nuclear medicine. 125r, with a half-life of 60 days, has a crucial role in competitive protein-binding studies. 131r is useful for measuring thyroid uptake, for the diagnosis of thyroid carcinoma and metastasis, and for therapy. 1nr , with a reasonably shorter half-life, is almost ideal for thyroid workup and for a few useful labeled radiopharmaceutical. Although ~c is used more widely in diagnostic procedures, the radionuclides of iodine will always have a major role in biology and medicine. A considerable amount of information is scattered in the literature regarding the chemistry of radioiodination and the mechanism of tracer localization in cells and tissues. Labeled peptides, proteins, and antibodies are extensively used for protein turnover studies, receptor binding and tumor imaging studies, and radioimmunoassay. The general trend in the use of tracers in clinical nuclear medicine has been an evolution from 3H, 14C, 11C, and 13 to 125 , 131 and 123r to ~c and 111rn.
Preface. Part I: Introduction. 1. History of Development of Iodine-Labeled Tracers. 2. Physical Decay Characteristics of Radioisotopes of Iodine. 3. Principles of Measurement of Radioiodinated Tracers and Related Instruments. 4. Radiation Dosimetry of Iodine-Labeled Tracers. 5. Hazards in the Handling of Radioiodine-Labeled Compounds and Central Facility for Radioiodination. 6. Production of 131I, 125I and 123I Radionuclides and their Separation from Targets. Part II: Preparation of Tracers. 7. Chemistry of Radioiodination Reactions. Part III: Localization of Tracers. 8. Methods of Radioiodination Reactions with Several Oxidizing Agents. 9. Mechanisms of Tracer Localization. Part IV: Organ Imaging and Tracer Applications. 10. Radioiodinated Small Molecules and their Applications. 11. Radioiodinated Macromolecules. 12. Applications of Radioiodinated Macromolecules. 13. Radioiodinated Lipoproteins. 14. Radioiodinated Peptides and Growth Factors and their Applications. 15. Miscellaneous Radioiodinated Polymers and Beads. 16. Radioiodinated Haptens and their Applications. Part V: Purification of Substrate, Quality Control of Tracers and Radiation Damage During Storage. 17. Preparation and Purification of Substrates and Proteins before and after Radioiodination. 18. Quality Control of Radioiodinated Products. 19. Specific Activity and Radiation Damage in Tracers during Storage.