# 131I-MIBG (iobenguane I-131) therapy

Source: https://nuclide.cc/drugs/i131-mibg/  
Nuclide record `i131-mibg` (Agent). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

High-dose radioactive MIBG delivers radiation from inside neuroblastoma cells that take up noradrenaline; used for relapsed disease and tested in upfront therapy.

## Summary

Response rate ~30-40% in relapsed/refractory MIBG-avid neuroblastoma (NANT, COG studies), with myelosuppression requiring stem-cell support at ≥12 mCi/kg. COG ANBL1531 randomised 131I-MIBG added to induction (primary results pending 2026). Commercial Azedra (for pheochromocytoma) was discontinued in 2024, leaving compounding and academic supply.

## Fields

- Kind: Agent
- Status: established
- Last checked: 2026-09-07
- Modality: Radioligand therapy (beta, norepinephrine transporter)
- Mechanism: Norepinephrine transporter uptake of radio-iodinated benzylguanidine; 131I beta emission (2 mm range).
- Dosing: IV; 12-18 mCi/kg single or tandem doses with autologous stem-cell support; thyroid blockade with potassium iodide

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Iobenguane
- Wikipedia: https://en.wikipedia.org/wiki/Iobenguane

## Connected records

- isotopes: [Iodine-123](https://nuclide.cc/isotopes/i-123/), [Iodine-131](https://nuclide.cc/isotopes/i-131/)
- indications: [High-risk neuroblastoma](https://nuclide.cc/indications/neuroblastoma-high-risk/), [Metastatic pheochromocytoma and paraganglioma](https://nuclide.cc/indications/metastatic-ppgl/), [Neuroblastoma (paediatric)](https://nuclide.cc/indications/neuroblastoma/), [Pheochromocytoma and paraganglioma (PPGL)](https://nuclide.cc/indications/pheochromocytoma-paraganglioma/)
- technologies: [MIBG imaging and 131I-MIBG therapy](https://nuclide.cc/technologies/mibg-theranostics/), [Radioligand therapy (beta emitters)](https://nuclide.cc/technologies/radioligand-therapy/)
- companies: [Lantheus](https://nuclide.cc/companies/lantheus/)
- trials: [COG ANBL1531](https://nuclide.cc/trials/anbl1531/)
- terms: [MIBG Curie and SIOPEN scores](https://nuclide.cc/terms/curie-siopen-score/)
- people: [Katherine K. Matthay](https://nuclide.cc/people/katherine-matthay/)
- key papers: [Efficacy and safety of high-specific-activity 131I-MIBG therapy in advanced pheochromocytoma or paraganglioma](https://nuclide.cc/key-papers/paper-pryma-high-specific-activity-i131-mibg-ppgl-jnm-2019/)
- drugs: [Iobenguane I-123](https://nuclide.cc/drugs/i-123-mibg/), [Iobenguane I-123 (cardiac use)](https://nuclide.cc/drugs/i-123-mibg-cardiac/)
- targets: [Norepinephrine transporter (NET)](https://nuclide.cc/targets/norepinephrine-transporter/)

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