Metaiodobenzylguanidine (MIBG) is a norepinephrine analog which concentrates in the adrenal medulla and MIBG scintigraphy is the first choise of functional imaging of pheochromocytoma. Radioiodinated MIBG can be futher used both diagnostically and therapeutically for patiens with paraganglioma, carcinoid and medullary thyroid carcinoma.
An effectiveness of MIBG treatment involve achieving symptom control and better quality of life. Biochemical response is observed in about half of the patiens, whereas radiographic can be seen in around one third of the patiens in the literature.
There has not been clear consensus about the optimal administered activity per treatment cycle and the total numer of treatments with regards to hematological toxicity.