Skip to main content
An official website of the United States government
NIH Websites Are Changing
Per Executive Order 14434, federal agencies are now using "Super Intelligence" (SI) in place of "Artificial Intelligence" (AI). You may see both terms across NIH content during this transition.

iodine I 123

A radioactive isotope of iodine, a nonmetallic element of the halogen group with an atomic mass of 123 and a half-life of 13.2 hours with radioisotopic activity. Selectively accumulating in the thyroid tissue, iodine I 123 emits gamma rays that can be detected with gamma scintigraphy, allowing localization of thyroid tissue. This agent may be used as a tracer in whole body scintigraphy (WBS) to localize thyroid carcinoma metastases.
Check for active clinical trials using this agentView this agent in the NCI Thesaurus
Synonym:I-123
iodine 123
Search NCI's Drug Dictionary
Please enter up to 30 characters for your search