Functional imaging of neuroendocrine tumours with PET

Several pathophysiological attributes of neuroendocrine tumours (NET) can be addressed by specific radiolabelled probes. This paper provides an overview on the different radiopharmaceuticals that have been developed for Positron Emission Tomography (PET) of neuroendocrine tumours. A review of the literature on 18F-fluordeoxyglucose (FDG), biogenic amine precursors, somatostatin analogues and hormone syntheses markers is presented. Due to the highly specific tracers that lack any clear anatomical landmarking the advantages of integrated PET/CT are obvious. Amine precursors should be employed in most gastroenteropancreatic NET, FDG should be preserved for more aggressive, less differentiated NETs. Somatostatin analogues are the most promising tracers, since they can improve dosimetry in cases in which radiopeptide therapies are planned. In conclusion, the individual diagnostic approach using PET or the integrated PET/CT should be tailored depending on the histological classification and the differentiation of the tumour.