I-131 iodocholesterol

I-131 iodocholesterol (131I-19-iodocholesterol) is a radiopharmaceutical diagnostic agent developed for the visualization of the adrenal cortex. It consists of cholesterol labeled with the radioisotope iodine-131. As cholesterol is a primary precursor for steroid hormone synthesis, the radiotracer is taken up by the adrenal glands via lipoprotein receptors, primarily the low-density lipoprotein (LDL) receptor. Once accumulated, the gamma emissions from I-131 allow for scintigraphic imaging (gamma imaging) to evaluate adrenal function and detect abnormalities such as Cushing's syndrome, primary hyperaldosteronism, and adrenal neoplasms (adenomas and carcinomas). While it was a pioneering agent in adrenal imaging, it was largely superseded by the second-generation agent NP-59 (131I-6β-iodomethyl-19-norcholesterol) due to the latter's higher adrenal avidity and lower background interference.

Other names

Iodine I-131 Iodocholesterol19-iodocholesterol131I-cholesterol