Tc-99m-(V)-DMSA: the new sensitive and specific radiopharmaceutical for imaging metastases of medullary thyroid carcinomas?

In the follow-up of five patients with histologic proven medullary thyroid carcinoma (MTC) and raised serum calcitonin and CEA levels the pentavalent Tc-99m-(V)-DMSA and the Tc-99m-MDP bone scan had the highest sensitivity in the localisation of metastases. Both methods are not tumor specific. A false positive Tc-99m-(V)-DMSA uptake in an old osteomyelitis of one vertebra could be demonstrated. The J-123-MIBG and In-111-F(ab2)' antibody scan did not allow to localise one of the above described metastases. In conclusion in the follow-up of patients with MTC and elevated tumor marker concentrations the Tc-99m-(V)-DMSA and the Tc-99m-MDP bone scan should be the second diagnostic procedures after sonography has been performed.