Initial Results with [18F]FAPI-74 PET/CT in Idiopathic Pulmonary Fibrosis

Abstract Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing interstitial lung disease with a poor prognosis. 68 Ga-labelled FAP ligands exhibited highly promising results due to the crucial role of activated fibroblasts in fibrosis imaging of the lung. However, 18 F-labelled FAP ligands might provide qualitatively much higher imaging results with accompanying economic benefits due to large-scale production. Thus, we sought to investigate the potential of [ 18 F]FAPI-74 prospectively in a small patient cohort. Methods : Eight patients underwent both [ 18 F]FAPI-74-PET/CT and HRCT scans and were then compared with a control group without any fibrosing pulmonary disease. The tracer uptake of fibrotic lung areas was analyzed in synopsis with radiological, and clinical parameters. Results : We observed a positive correlation of the fibrotic active volume, Hounsfield scale as well as vital and diffusing capacity of the lung. Conclusion : The initial results confirm our assumption that [ 18 F]FAPI-74 offers a viable non-invasive assessment method for pulmonary fibrotic changes of patients with IPF.