Somatostatin Receptor Scintigraphy in Medullary Thyroid Cancer

Medullary thyroid cancer (MTC) is a neuroendocrine tumor originating from the calcitonin‐secreting C cells. Surgery, consisting of a total thyroidectomy and an extensive lymph node dissection, is the only effective treatment in MTC; however, metastases are frequently found in the regional cervical lymph. The biochemical marker for MTC is calcitonin, and this is frequently used for the detection of persistent/residual/metastatic tumor. The value of 111In‐labeled somatostatin receptor scintigraphy (SRS) in patients with MTC is limited, with sensitivity ranging between 0 and 75%. Other scintigraphic imaging techniques such as 18F‐FDG PET, 18F‐DOPA PET, and PET imaging with 68Ga‐labeled DOTA peptides combined with CT imaging are upcoming. Treatment of patients with metastatic disease with the current available somatostatin analogues, octreotide and lanreotide, does not seem to have an effect on survival but may be considered to control flushing and diarrhea in some patients. Experience with peptide receptor radionuclide therapy is limited in this patient group and disappointing. New therapies in the treatment of metastatic MTC use target tyrosine kinase receptors inhibitors belonging to the same family group of proteins as RET.