Secondary liver lesions are frequently encountered in neuroendocrine tumours (NET) of the
gastro-entero-pancreatic tract. Although conventional morphologic imaging modalities and somatostatin
receptor scintigraphy (SRS) have been extensively used in past decades, with the advent of PET/CT,
new diagnostic procedures are currently available with the employment of different beta emitting
tracers. In fact NET can be easily visualised on PET scans using an array of both metabolic and
receptor-based tracers. 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (18F-DOPA) and 68Ga-DOTApeptides
(DOTA-TOC, DOTA-NOC, DOTA-TATE) are very promising to image well-differentiated
NET and were reported to be superior to other imaging modalities (CT, SRS). On the contrary, the role
of 18F-FDG is limited in well-differentiated NET, due to their low glucose metabolism and growth rate,
while it can still provide valuable information in less differentiated NET or in forms with lower
expression of somatostatin receptors.
Keywords: PET; CT; Neuroendocrine tumours; 18F-FDG; 18F-DOPA; 68Ga-DOTA-peptides