Advances in the Diagnosis of Neuroendocrine Neoplasms

Somatostatin receptor PET/CT using 68Ga-labeled somatostatin analogs, is a mainstay for the evaluation of the somatostatin receptor status in neuroendocrine neoplasms. In addition, the assessment of glucose metabolism by 18F-FDG PET/CT at diagnosis can overcome probable shortcomings of histopathologic grading. This offers a systematic theranostic approach for the management of neuroendocrine neoplasms, that is, patient selection for the appropriate treatment—surgery, somatostatin analogs, peptide receptor radionuclide therapy, targeted therapies like everolimus and sunitinib, or chemotherapy—and also for therapy response monitoring. Novel targets, for example, the chemokine receptor CXCR4 in higher-grade tumors and glucagon like peptide-1 receptor in insulinomas, appear promising for imaging. Scandium-44 and Copper-64, especially on account of their longer half-life (for pretherapeutic dosimetry) and cyclotron production (which favors mass production), might be the potential alternatives to 68Ga for PET/CT imaging. The future of molecular imaging lies in Radiomics, that is, qualitative and quantitative characterization of tumor phenotypes in correlation with tumor genomics and proteomics, for a personalized cancer management.