Metastatic Medullary Thyroid Cancers: Challenges in Diagnosis with Nuclear Medicine Techniques and the Role of Radionuclide Therapy

Medullary thyroid cancer is a rare tumor driven from neuroendocrine cells. In the last decade there has been important discoveries regarding its genetics and relationship between genotype and phenotype on familial cases. However remains unknown the best approach for patient with maintained high levels of tumor markers such as calcitonin. Most available imaging techniques are able to accurately find metastatic lesions only in advanced disease. Traditionaly, nuclear medicine images are able to find metastatic suspicious lesions before they reach the size to be considered suspicious in conventional studies such as computed tomography scans or magnetic resonance imaging. However in patients with medullary thyroid cancer the ideal radiopharmaceutical for this purpose is yet to be found. Based on the biology of the tumor, some radiopharmaceuticals have been studied for diagnosis and also for therapy in those patients. The aim of this review is to describe the radiopharmaceuticals used for diagnosis and treatment until today and the role of each of them in medical care. In conclusion, the medullary thyroid cancer is a rare tumor and the review shows that despite all studies there is still no consensus on the importance of nuclear medicine in the diagnosis and treatment of these patients. Further studies are still needed.