Recent advances in nuclear medicine and their role in inflammatory arthritis: focus on the emerging role of FAPI PET/CT

Skeletal Radiol. 2025 Nov;54(11):2243-2252. doi: 10.1007/s00256-024-04834-w. Epub 2024 Nov 25.

Abstract

Imaging molecular processes associated with inflammatory disease has been revolutionized by hybrid imaging using positron emission tomography/computed tomography (PET/CT). PET/CT visualizes metabolic activity as well as protein expression and provides a comprehensive whole-body evaluation. It has the potential to reveal inflammation prior to detection of structural changes in inflammatory joint diseases. FAP is a type II transmembrane glycoprotein overexpressed not only in the stroma of tumors but also in the fibrotic processes of certain immune-mediated disorders. The recent introduction of fibroblast activation protein inhibitors (FAPI) labeled by positron emitters and thus suitable for PET/CT allows to investigate FAP expression in vivo. This review will focus on the use of FAPI-PET/CT for the diagnosis and evaluation of treatment response in inflammatory joint diseases.

Keywords: FAPI; Joint diseases; Molecular imaging; PET/CT.

Publication types

  • Review

MeSH terms

  • Arthritis* / diagnostic imaging
  • Endopeptidases
  • Fibroblast Activation Protein Alpha
  • Gelatinases* / antagonists & inhibitors
  • Gelatinases* / metabolism
  • Humans
  • Membrane Proteins* / antagonists & inhibitors
  • Membrane Proteins* / metabolism
  • Positron Emission Tomography Computed Tomography* / methods
  • Positron Emission Tomography Computed Tomography* / trends
  • Radiopharmaceuticals
  • Serine Endopeptidases* / metabolism

Substances

  • Radiopharmaceuticals
  • Membrane Proteins
  • Gelatinases
  • Serine Endopeptidases
  • Endopeptidases
  • Fibroblast Activation Protein Alpha