Correlation of FAPI PET Uptake with Immunohistochemistry in Explanted Lungs from Patients with Advanced Interstitial Lung Disease
1
Issued Date
2024-11-01
Resource Type
eISSN
15355667
Scopus ID
2-s2.0-85208450553
Pubmed ID
39362770
Journal Title
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
Volume
65
Issue
11
Start Page
1789
End Page
1794
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of nuclear medicine : official publication, Society of Nuclear Medicine Vol.65 No.11 (2024) , 1789-1794
Suggested Citation
Hotta M., Kim G.H.J., Rerkpichaisuth V., Teng P.Y., Armstrong W.R., Carlucci G., Dahlbom M., Abtin F., Lari S.M., Fishbein G.A., Czernin J., Volkmann E.R., Weigt S.S., Calais J. Correlation of FAPI PET Uptake with Immunohistochemistry in Explanted Lungs from Patients with Advanced Interstitial Lung Disease. Journal of nuclear medicine : official publication, Society of Nuclear Medicine Vol.65 No.11 (2024) , 1789-1794. 1794. doi:10.2967/jnumed.124.268351 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/102029
Title
Correlation of FAPI PET Uptake with Immunohistochemistry in Explanted Lungs from Patients with Advanced Interstitial Lung Disease
Corresponding Author(s)
Other Contributor(s)
Abstract
Recent studies have demonstrated promising results of fibroblast activation protein (FAP) inhibitor (FAPI) PET in prognosticating and monitoring interstitial lung diseases (ILDs). As a first step toward successful translation, our primary aim was to validate the FAPI PET uptake through immunohistochemistry in patients with advanced ILD who underwent lung transplantation after a FAPI PET scan. Methods: This is a preliminary analysis of a single-center, open-label, single-arm, prospective exploratory biodistribution study of 68Ga-FAPI-46 PET imaging in patients with ILD (NCT05365802). Patients with ILD confirmed by high-resolution CT and scheduled for lung transplant were included. Tissue samples of explanted lungs were obtained from both the central and peripheral lung parenchyma of each lobe. Additional samples were obtained from areas of the lung corresponding to regions of FAPI PET activity. Immunohistochemical staining was performed with an anti-FAP antibody. Percentages of FAP immunohistochemistry-positive area were measured semiautomatically using QuPath software. SUVs in the areas of pathologic samples were measured on FAPI PET/CT by referencing the gross photomap of the explanted lung. A Spearman correlation coefficient test was used to assess the relationship between FAPI PET uptake and FAP immunohistochemical expression in each specimen. Results: Four patients with advanced ILD who underwent FAPI PET/CT before lung transplantation were included. The types of ILD were idiopathic pulmonary fibrosis (n = 2), rheumatoid arthritis-associated ILD (n = 1), and nonspecific interstitial pneumonia (n = 1). FAPI uptake was visualized mainly in the fibrotic area on CT. Twenty-nine surgical pathology samples from 3 patients were analyzed. FAP staining was predominantly positive in fibroblastic foci. FAPI PET SUVmax and SUVmean showed a positive correlation with the immunohistochemical FAP expression score (SUVmax: r = 0.57, P = 0.001; SUVmean: r = 0.54, P = 0.002). Conclusion: In this analysis conducted in patients who underwent lung transplantation after a FAPI PET scan, FAPI PET uptake was positively correlated with FAP immunohistochemistry. These findings provide a rationale for further investigation of FAPI PET as a potential imaging biomarker for ILD.