Non-malignant findings of focal 68Ga-FAPI-04 uptake in pancreas



68Ga-Labelled Fibroblast Activation Protein Inhibitor (68Ga-FAPI) has shown promise in tumour positron emission tomography (PET) imaging, including malignant pancreatic lesions. Here, we showed several non-malignant findings of focal 68Ga-FAPI-04 uptake in the pancreas which were occasionally found by PET/MR. The study aimed to investigate the reasons for the focal uptake and remind caution for the diagnosis.


We retrospectively analysed imaging data of 103 patients who underwent 68Ga-FAPI-04 PET/MR at our institute from May 22 to July 8, 2020. Seven patients had focally elevated uptake of 68Ga-FAPI-04 in the pancreas; four of these underwent simultaneous 18F-FDG PET/CT scans. The clinical data, PET/MR imaging features, pathological, and follow-up results were further collected and analysed.


The cases showed that 68Ga-FAPI-04 accumulation can occur in any part of the pancreas, with corresponding negative 18F-FDG uptake. Most lesions were small with no significant changes in CT or MR signals. The SUVmax value of 68Ga-FAPI-04 had a wide range of 3.1–9.1. All the pancreatic lesions were proven to be non-neoplastic by pathology confirmation or follow-up imaging. Lesions with uptake were identified including pancreatic pseudocysts, sites of prior pancreatitis, and foci of IgG 4-related disease.


Though 68Ga-FAPI-04 demonstrates great potential for oncological diagnosis, focal 68Ga-FAPI-04 uptake could occur in benign pancreatic lesions and should be carefully evaluated. Fortunately, combined with MR, 68Ga-FAPI-04 PET/MR may potentially avoid the misdiagnosis of some pancreatic lesions.

Clinical Trial Registration: NCT04554719 and NCT04605939. Registered September 13, 2020 and October 25, 2020, respectively.

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  1. 1.

    Meyer C, Dahlbom M, Lindner T, Vauclin S, Mona C, Slavik R, et al. Radiation dosimetry and biodistribution of (68)Ga-FAPI-46 PET imaging in cancer patients. J Nucl Med. 2020;61(8):1171–7.

    CAS  Article  PubMed  Google Scholar 

  2. 2.

    Langbein T, Weber WA, Eiber M. Future of theranostics: an outlook on precision oncology in nuclear medicine. J Nucl Med. 2019;60(Suppl 2):13S–9S.

    CAS  Article  PubMed  Google Scholar 

  3. 3.

    Hamson EJ, Keane FM, Tholen S, Schilling O, Gorrell MD. Understanding fibroblast activation protein (FAP): substrates, activities, expression and targeting for cancer therapy. Proteomics Clin Appl. 2014;8(5-6):454–63.

    CAS  Article  PubMed  Google Scholar 

  4. 4.

    Toms J, Kogler J, Maschauer S, Daniel C, Schmidkonz C, Kuwert T, et al. Targeting fibroblast activation protein: radiosynthesis and preclinical evaluation of an (18)F-labeled FAP inhibitor. J Nucl Med. 2020.

  5. 5.

    Giesel FL, Kratochwil C, Lindner T, Marschalek MM, Loktev A, Lehnert W, et al. (68)Ga-FAPI PET/CT: biodistribution and preliminary dosimetry estimate of 2 DOTA-containing FAP-targeting agents in patients with various cancers. J Nucl Med. 2019;60(3):386–92.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  6. 6.

    Chen H, Pang Y, Wu J, Zhao L, Hao B, Wu J, et al. Comparison of [(68)Ga]Ga-DOTA-FAPI-04 and [(18)F] FDG PET/CT for the diagnosis of primary and metastatic lesions in patients with various types of cancer. Eur J Nucl Med Mol Imaging. 2020;47(8):1820–32.

    Article  PubMed  Google Scholar 

  7. 7.

    Luo Y, Pan Q, Zhang W, Li F. Intense FAPI uptake in inflammation may mask the tumor activity of pancreatic cancer in 68Ga-FAPI PET/CT. Clin Nucl Med. 2020;45(4):310–1.

    Article  PubMed  Google Scholar 

  8. 8.

    Shi X, Xing H, Yang X, Li F, Yao S, Zhang H, et al. Fibroblast imaging of hepatic carcinoma with (68)Ga-FAPI-04 PET/CT: a pilot study in patients with suspected hepatic nodules. Eur J Nucl Med Mol Imaging. 2020.

  9. 9.

    Syed M, Flechsig P, Liermann J, Windisch P, Staudinger F, Akbaba S, et al. Fibroblast activation protein inhibitor (FAPI) PET for diagnostics and advanced targeted radiotherapy in head and neck cancers. Eur J Nucl Med Mol Imaging. 2020.

  10. 10.

    Calais J, Mona CE. Will FAPI PET/CT replace FDG PET/CT in the next decade?-Point: an important diagnostic, phenotypic and biomarker role. AJR Am J Roentgenol. 2020.

  11. 11.

    Chen H, Zhao L, Ruan D, Pang Y, Hao B, Dai Y, et al. Usefulness of [(68)Ga]Ga-DOTA-FAPI-04 PET/CT in patients presenting with inconclusive [(18)F]FDG PET/CT findings. Eur J Nucl Med Mol Imaging. 2020.

  12. 12.

    Moradi F, Iagaru A. Will FAPI PET/CT replace FDG PET/CT in the next decade?-Counterpoint: no, not so fast! AJR Am J Roentgenol. 2020.

  13. 13.

    Pan Q, Luo Y, Zhang W. Recurrent immunoglobulin G4-related disease shown on 18F-FDG and 68Ga-FAPI PET/CT. Clin Nucl Med. 2020;45(4):312–3.

    Article  PubMed  Google Scholar 

  14. 14.

    Schmidkonz C, Rauber S, Atzinger A, Agarwal R, Gotz TI, Soare A, et al. Disentangling inflammatory from fibrotic disease activity by fibroblast activation protein imaging. Ann Rheum Dis. 2020;79(11):1485–91.

    CAS  Article  PubMed  Google Scholar 

  15. 15.

    Luo Y, Pan Q, Zhang W. IgG4-related disease revealed by (68)Ga-FAPI and (18)F-FDG PET/CT. Eur J Nucl Med Mol Imaging. 2019;46(12):2625–6.

    Article  PubMed  Google Scholar 

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This work was supported by National Natural Science Foundation of China (No. 82030052, and 81901783).

Author information




X. L. conceived and designed the study devised, and supervised the project. X. Z. and W. S. wrote the manuscript. C. Q. and F. L. analysed the image data. X. Z. and W. S. contributed to the follow-up of the patients.

Corresponding author

Correspondence to Xiaoli Lan.

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This article is part of the Topical Collection on Oncology - Digestive tract.

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Zhang, X., Song, W., Qin, C. et al. Non-malignant findings of focal 68Ga-FAPI-04 uptake in pancreas. Eur J Nucl Med Mol Imaging (2021).

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  • 68Ga-FAPI-04
  • 18F-FDG
  • Non-malignant
  • Pancreas