Azedra

Iobenguane, or MIBG, is an aralkylguanidine analog of the adrenergic neurotransmitter, typically used as a radiopharmaceutical.[1] It acts as a blocking agent for adrenergic neurons. When radiolabeled, it can be used in nuclear medicinal diagnostic and therapy techniques as well as in neuroendocrine chemotherapy treatments. It localizes to adrenergic tissue and thus can be used to identify the location of tumors such as pheochromocytomas and neuroblastomas.[2] ... [wikipedia]