State of the Art and Recent Developments of Radiopharmaceuticals for Pancreatic Neuroendocrine Tumors Imaging

Curr Radiopharm. 2019;12(2):107-125. doi: 10.2174/1874471012666190306104450.

Abstract

Background: Neuroendocrine Tumors (NETs) are relatively rare tumors, mainly originating from the digestive system, that tend to grow slowly and are often diagnosed when metastasised. Surgery is the sole curative option but is feasible only in a minority of patients. Among them, pancreatic neuroendocrine tumors (pancreatic NETs or pNETs) account for less than 5% of all pancreatic tumors. Viable therapeutic options include medical treatments such as biotherapies and more recently Peptide Receptor Radionuclide Therapies (PRRT) with radiolabeled somatostatin analogues. Molecular imaging, with main reference to PET/CT, has a major role in patients with pNETs.

Objective: The overexpression of specific membrane receptors, as well as the ability of cells to take up amine precursors in NET, have been exploited for the development of specific targeting imaging agents.

Methods: SPECT/CT and PET/CT with specific isotopes such as [68Ga]-1,4,7,10-tetra-azacyclododecane- N,N',N'',N'''-tetra-acetic acid (DOTA)-somatostatin analogs, [18F]-FDG and [18F]-fluorodopa have been clinically explored.

Results: To overcome the limitations of SSTR imaging, interesting improvements are connected with the availability of new radiotracers, activating with different mechanisms compared to somatostatin analogues, such as glucagon-like peptide 1 receptor (GLP-1 R) agonists or antagonists.

Conclusion: This paper shows an overview of the RPs used so far in the imaging of pNETs with insight on potential new radiopharmaceuticals currently under clinical evaluation.

Keywords: Neuroendocrine tumors; PET/CT; imaging; pancreas; radionuclide therapies; radiopharmaceuticals..

Publication types

  • Review

MeSH terms

  • Amines
  • Carcinoid Tumor / diagnostic imaging
  • Cell Differentiation
  • Humans
  • Indium Radioisotopes
  • Islets of Langerhans / pathology
  • Neuroendocrine Tumors / diagnostic imaging*
  • Pancreatic Neoplasms / diagnostic imaging*
  • Positron Emission Tomography Computed Tomography / trends
  • Radiopharmaceuticals / pharmacology*
  • Receptors, Somatostatin / metabolism
  • Tomography, Emission-Computed, Single-Photon

Substances

  • Amines
  • Indium Radioisotopes
  • Radiopharmaceuticals
  • Receptors, Somatostatin