68Ga-labelled peptides for diagnosis of gastroenteropancreatic NET.

In the past few years, the introduction of novel PET tracers labelled with (68)Ga has changed the diagnostic approach to neuroendocrine tumours (NET) in specialized centres. Although somatostatin analogue tracers labelled with (111)In have represented the gold standard imaging modality for NET detection in past decades, the advantages offered by both labelling somatostatin analogues with (68)Ga and using PET/CT tomography for image acquisition, account for the increasing use of these tracers in clinical practice. There are an increasing number of reports of the higher accuracy of (68)Ga-DOTA peptide PET/CT for the detection of NET lesions as compared to morphological imaging procedures and somatostatin receptor scintigraphy. Moreover, the use of (68)Ga-DOTA peptides offers the possibility to noninvasively evaluate NET cells for the presence of somatostatin receptor expression, with direct therapeutic implications. Several practical advantages also favour the use of (68)Ga-DOTA peptides including the relatively easy and economic synthesis process and the fact that (68)Ga labelling can be performed in centres without an on-site cyclotron. We describe the advantages and limitations of (68)Ga-DOTA peptide PET/CT imaging for the assessment of gastroenteropancreatic NET referring to the available literature as well as to our experience, and finally highlight potential future perspectives.