Radiopharmaceuticals for nuclear endocrinology at the University of Michigan.

The historical background at the University of Michigan laid a foundation for the innovative development of radionuclides in diagnosis and treatment of endocrine diseases. From that background, Dr. William Beierwaltes, the chief of Nuclear Medicine, inspired two talented young chemists to synthesize unique radiopharmaceuticals that transformed diagnostic approaches to certain endocrine disorders. Dr. Raymond Counsell's 131-I-radiocholesterol, enabled imaging that defined function in the adrenal cortex, and thereby distinguished the different forms of Cushing's syndrome and of primary aldosteronism; in addition, this new technique differentiated benign adrenal cortical adenomas from other adrenal cortical tumors. Dr. Donald Wieland created metaiodobenzlylguanidine (MIBG), a compound that can be tagged with either 131-I or 123-I, and led to the scintigraphic depiction of adrenergic tumors, particularly pheochromocytomas and neuroblastoma, anywhere in the body of a patient. Treatments with large doses of MIBG have reduced the malignant forms of pheochromocytomas and brought remissions to children with neuroblastomas. MIBG also concentrated in the autonomic neurons and so the nerves of the heart were also portrayed. Subsequent novel syntheses included positron-emitting nuclides that, through positron emission tomography, have revealed the physiology and altered physiology of the human heart. These men and their discoveries exemplify the creative endeavors that compel us to seek further the wonders of nuclear science.