Nuclear medicine in NET.

Neuroendocrine tumors (NET) are, despite increasing incidence, still rare, usually slow growing neoplasms with resemblance to nerve cells and the endocrine capability of hormone production. In contrast to commonly used conventional imaging procedures, nuclear imaging is feasible to visualize the presence of molecular biomarkers, particularly the overexpression of somatostatin receptors (sstr) with high diagnostic accuracy which has led to the establishment of somatostatin receptor scintigraphy (SRS) as essential component and gold standard of functional imaging in the workup of NET. Another major feature is the selection of patients with inoperable or metastasized tumors showing sufficient uptake for peptide receptor radionuclide therapy (PRRT). While somatostatin receptor PET and PET/CT using Ga-68-labeled SSR analogs represents the consistent further development of SRS, FDG-PET can only be used in tumors with high proliferative activity but not on a routine basis for imaging of neuroendocrine tumors. (18)F-DOPA represents an alternative PET tracer worth mentioning currently under assessment for NET imaging.