Henry Ford Hospital Medical Journal


We assessed the uptake of two new radiopharmaceuticals, 131I meta-iodo-benzylguanidine (MIBG) and 99mTc(V) dimercaptosuccinic acid (DMSA), in patients with histologically proven medullary thyroid carcinoma (MTC). MIBG detected tumor in 40% of patients with known primary or recurrent tumor. 99m Tc(V) DMSA successfully demonstrated primary and recurrent tumor in 86% of patients imaged, with true negative results in 100% of patients imaged after successful surgical resection and a false-negative rate of 14%. We therefore suggest that 99m Tc(V) DMSA is the imaging agent of choice in patients with both primary and recurrent disease. 131I MIBG, with its high false-negative rate, has no place in tumor localization, but its potential role in therapy warrants further evaluation.