Iodine-131-MIBG Therapy of a Patient with Carcinoid Liver Metastases

Iodine-13I-metaiodobenzylguanidine (MIBG) is highly concentrated by >60% of carcinoid metastases and thus provides a therapeutic opportunity. A symptomatic patient with carcinoid liver metastases, unresponsive to chemotherapy combined with interferon-alpha, was subsequently treated with 131I-MIBG. Radionuclide therapy, which was without significant side effects, resulted in symptomatic improvement and reduced urinary 5-hydroxyindoleacetic acid levels. No new metastases were observed for 15 mo after 131I-MIBG therapy. Gross cystic change occurred in existing liver metastases, presumably as a result of ischemic necrosis. Surgical deroofing and aspiration of cysts led to regeneration of normal liver tissue. Iodine-131-MIBG therapy can provide prolonged symptomatic relief and improved quality of life in patients with metastatic carcinoid disease unresponsive to other therapies. The antitumor effect of 131I-MIBG was accompanied by few side effects, suggesting that this therapy should be considered in symptomatic patients with an early stage of disease.