Radiochemistry, biochemistry, and kinetics of 131I-metaiodobenzylguanidine (MIBG) and 123I-MIBG: clinical implications of the use of 123I-MIBG

Med Pediatr Oncol. 1987;15(4):170-7. doi: 10.1002/mpo.2950150406.


Metaiodobenzylguanidine (MIBG) is actively concentrated in adrenergic neuroendocrine tissues and tumors by an active, energy- and sodium-dependent, high-affinity, saturable mechanism. This has proved successful, when labeled with 131-I or 123-I, in scintigraphically depicting pheochromocytomas and neuroblastomas. For imaging purposes 123-I has multiple advantages over 131-I; the gamma ray energy is ideal for modern instruments, the decay by electron capture limits the particulate emissions, and the short half-life reduces the radiation burden. It is thus possible to use doses of 123-I-MIBG 20 times as large as doses of 131-I-MIBG with equivalent absorbed radiation doses. Disadvantages of 123-I include the cost and difficulties in the regular delivery of this short-lived radionuclide. For most imaging purposes 123-I-MIBG is the optimal agent if logistical problems in its supply can be overcome.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • 3-Iodobenzylguanidine
  • Adrenal Gland Neoplasms / diagnosis
  • Adrenal Gland Neoplasms / pathology
  • Animals
  • Humans
  • Iodine Radioisotopes
  • Iodobenzenes / pharmacokinetics*
  • Neuroblastoma / diagnosis*
  • Neuroblastoma / pathology
  • Pheochromocytoma / diagnosis
  • Pheochromocytoma / pathology


  • Iodine Radioisotopes
  • Iodobenzenes
  • 3-Iodobenzylguanidine