In medicine, endocrinology is perhaps the domain that encompasses the most molecular imaging using radioactive agents, also called radiopharmaceuticals. This is due to the diversity of molecular targets, including hormone synthesis pathways expressed uniquely by endocrine tumors and the growing knowledge in their pathophysiology and genetics. Those radiopharmaceuticals not only serve as diagnostic agents, but can also serve as a platform for characterizing endocrine disorders and treat patients and be used to monitor intracellular events that are induced by various therapies. Finally, they may be able to predict the aggressiveness and metastatic potential of endocrine tumors. This book provides comprehensive and up-to-date insights into the diagnostic, therapeutic, and future approaches of nuclear medicine to endocrine tumors in a new spirit of precision medicine. It will be of interest to practicing physicians, including nuclear medicine specialists, radiologists, endocrinologists, and oncologists, as well as fellows in training, students, and other health care professionals.