Neuroendocrine
neoplasms (NENs) are rare and heterogeneous
tumors that require multidisciplinary discussion for optimal care. The
theranostic approach (
DOTA peptides labelled with 68Ga for diagnosis and with 90Y or 177Lu for
therapy) plays a crucial role in the management of NENs to assess disease extension and as a criteria for
peptide receptor radionuclide therapy (PRRT) eligibility based on
somatostatin receptor (SSTR) expression. On the diagnostic side, [68Ga]Ga-
DOTA peptides PET/CT (SSTR PET/CT) is the gold standard for imaging well-differentiated SSTR-expressing
neuroendocrine tumors (NETs). [18F]FDG PET/CT is useful in higher grade NENs (NET G2 with Ki-67 > 10% and NET G3; NEC) for more accurate disease characterization and prognostication. Promising emerging
radiopharmaceuticals include
somatostatin analogues labelled with 18F (to overcome the limits imposed by 68Ga), and SSTR antagonists (for both diagnosis and
therapy). On the therapeutic side, the evidence gathered over the past two decades indicates that PRRT is to be considered as an effective and safe treatment option for SSTR-expressing NETs, and is currently included in the therapeutic algorithms of the main scientific societies. The positioning of PRRT in the treatment sequence, as well as treatment personalization (e.g., tailored dosimetry, re-treatment, selection criteria, and combination with other alternative treatment options), is warranted in order to improve its efficacy while reducing toxicity. Although very preliminary (being mostly hampered by lack of methodological standardization, especially regarding feature selection/extraction) and often including small patient cohorts, radiomic studies in NETs are also presented. To date, the implementation of radiomics in clinical practice is still unclear. The purpose of this review is to offer an overview of radiolabeled SSTR analogues for
theranostic use in NENs.