Nuclear medicine for general radiologists: endocrinological examinations

We reviewed nuclear endocrinological examinations of the thyroid, parathyroid, and adrenal glands that are clinically performed in Japan as well as somatostatin receptor imaging, which is widely used in Europe, the United States, and other countries. 123I thyroid scintigraphy is especially useful in detecting ectopic goiters and differentiating between Basedow's disease and subacute thyroiditis or Plummer's disease, all of which exhibit thyrotoxicosis. 201Tl is useful to detect foci metastasized from well differentiated thyroid cancer and to differentiate malignant from benign tumors. 67Ga-citrate is an agent used for patients suspected of having malignant lymphoma or undifferentiated carcinoma of the thyroid. Radioiodinated MIBG is a specific agent for medullary thyroid carcinoma. 99mTc-MIBI is a good agent for locating hyperfunctioning parathyroid tissues. 131I-adosterol is useful to locate the lesions of primary aldosteronism, Cushing's syndrome, adrenogenital syndrome, and select adenomas among incidental tumors. Radioiodinated MIBG scintigraphy has high diagnostic accuracy in locating pheochromocytomas and neuroblastomas. 111In-labeled octreotide is useful in locating, hormone-producing gastrointestinal and pancreatic tumors including carcinoids, gastrinomas, and insulinomas. Radiolabeled somatostatin receptor analogs are used not only to locate but also to treat malignant somatostatin receptor-positive tumors. We hope that Octreoscan will be available in Japan in the near future.