Molecular imaging of neuroendocrine tumors: Current applications and future trends.

in Diagnostic and interventional imaging by Ivan E Wang, Helen A SaTsu, Allen F Brooks, Rudolf A Werner, Steven P Rowe, Peter J H Scott, Benjamin L Viglianti

TLDR

  • The study reviews the current landscape of neuroendocrine neoplasm (NEN) imaging and discusses the emerging agents that can potentially contribute to NEN imaging in the future.

Abstract

The prevalence of neuroendocrine neoplasms (NEN), which include neuroendocrine tumors (NET) and neuroendocrine carcinomas (NEC), has increasing during recent years. The approval of diagnostic single-photon emission computed tomography and positron emission tomography imaging agents for NEN is an important factor in pushing the development of additional agents using new targets to develop patient-specific, targeted, radiopharmaceuticals. Numerous NEN-specific targets exist, including somatostatin receptors, norepinephrine transport substrates, amino acid transport substrates, and glucagon-like peptide-1 receptor analogues, as well as non-specific targets, such as glucose metabolism. Additionally, there are targets that can be used in combination with current agents to further personalize NEN imaging. In well-differentiated gastroenteropancreatic NET, [Ga]DOTATATE is the first line agent. In pheochromocytoma, paraganglioma, and neuroblastomas [I]MIBG can also be considered for imaging. [F]FDOPA is mainly used for midgut NETs but is second line if access to [Ga]DOTATATE is difficult. In insulinomas, glucagon like peptide-1 receptor agents can be considered with [Ga]DOTATATE. In medullary thyroid carcinomas, [F]FDOPA is preferred with or without [Ga]DOTATATE imaging. In poorly-differentiated NEN/NEC, non-specific agents such as [F]Fluoro-2-deoxy-d-glucose and [Ga]fibroblast activation protein inhibitor-04 can be used if somatostatin imaging is insufficient. Urokinase plasminogen activator receptor targeting has been used as a method for risk stratification and can be used in combination with [Ga]DOTATATE. The use of somatostatin receptor antagonists, bombesin receptor 2, C-X-C motif chemokine receptor-4, and glucose-dependent insulinotropic polypeptide receptor agents are currently in development - with all of them requiring further studies to determine their potential utility. This review analyzes the current landscape of NEN imaging and discusses the emerging agents that can potentially contribute to NEN imaging in the future.

Overview

  • The study examines the current landscape of neuroendocrine neoplasm (NEN) imaging and the emerging agents that can potentially contribute to NEN imaging in the future.
  • The authors discuss the importance of targeting specific receptors and transporters to develop patient-specific, targeted radiopharmaceuticals for NEN imaging.
  • The study also highlights the promising targets and agents that can be used in combination with current imaging agents to further personalize NEN imaging.

Comparative Analysis & Findings

  • The study compares the different imaging agents used for NEN imaging, including [Ga]DOTATATE, [I]MIBG, [F]FDOPA, and somatostatin receptor antagonists, among others.
  • The findings suggest that each agent has its own specific indications and strengths, and that a combination of agents may be required for optimal imaging results.
  • The study also identifies the limitations and potential drawbacks of each imaging agent and suggests future research directions to address these limitations.

Implications and Future Directions

  • The study's findings have significant implications for the development of new imaging agents and the improvement of NEN imaging.
  • The authors suggest that the use of emerging agents, such as somatostatin receptor antagonists, bombesin receptor 2, and C-X-C motif chemokine receptor-4 agents, may help to improve the accuracy and specificity of NEN imaging in the future.
  • Further clinical trials and studies are needed to determine the potential utility of these agents and to identify the best imaging protocols for different types of NEN.
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