68Ga-labelled peptides for diagnosis of gastroenteropancreatic NET

In the past few years, the introduction of novel PET tracers labelled with Ga-68 has changed the diagnostic approach to neuroendocrine tumours (NET) in specialized centres. Although somatostatin analogue tracers labelled with In-111 have represented the gold standard imaging modality for NET detection in past decades, the advantages offered by both labelling somatostatin analogues with Ga-68 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 Ga-68-DOTA peptide PET/CT for the detection of NET lesions as compared to morphological imaging procedures and somatostatin receptor scintigraphy. Moreover, the use of Ga-68-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 Ga-68-DOTA peptides including the relatively easy and economic synthesis process and the fact that Ga-68 labelling can be performed in centres without an on-site cyclotron. We describe the advantages and limitations of Ga-68-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.