iodine-124 metaiodobenzylguanidine

Iodine-124 metaiodobenzylguanidine (124I-MIBG) is a positron-emitting radiopharmaceutical designed for high-resolution Positron Emission Tomography (PET) imaging of neuroendocrine tumors. As a structural analog of the neurotransmitter norepinephrine and the antihypertensive drug guanethidine, it acts as a substrate for the norepinephrine transporter (NET/uptake-1). It is selectively taken up by cells of sympathomedullary and neuroectodermal origin—such as neuroblastoma, pheochromocytoma, and paraganglioma—where it is sequestered in neurosecretory storage granules. While 123I-MIBG is commonly used for SPECT imaging, the 124I isotope allows for the superior spatial resolution and quantitative accuracy of PET/CT. This is particularly valuable for lesion detection, staging, and performing patient-specific internal dosimetry for those scheduled to undergo radionuclide therapy with 131I-MIBG (e.g., Azedra).

Other names

124I-meta-iodobenzylguanidineiodine I 124 metaiodobenzylguanidineI124-MIBGI-124-MIBGI 124-MIBG