2-[(3-iodanylphenyl)methyl]guanidine

Iobenguane, also known as metaiodobenzylguanidine or mIBG, or MIBG (tradename Adreview) is a radiopharmaceutical, used in a scintigraphy method called MIBG scan. Iobenguane is a radiolabeled molecule similar to noradrenaline.
The radioisotope of iodine used for the label can be iodine-123 (for imaging purposes only) or iodine-131 (which must be used when tissue destruction is desired, but is sometimes used for imaging also).
Pheochromocytoma seen as dark sphere in center of the body (it is in the left adrenal gland). Image is by MIBG scintigraphy, with radiation from radioiodine in the MIBG. Two images are seen of the same patient from front and back. Note dark image of the thyroid due to unwanted uptake of iodide radioiodine from breakdown of the pharmaceutical, by the thyroid gland in the neck. Uptake at the side of the head are from the salivary glands. Radioactivity is also seen in the bladder, from normal renal excretion of iodide.
It localizes to adrenergic tissue and thus can be used to identify the location of tumors such as pheochromocytomas and neuroblastomas. With I-131 it can also be used to eradicate tumor cells that take up and metabolize norepinephrine.