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. ⁶⁸Ga-labeled FAP ligands exhibited highly promising results due to the crucial role of activated fibroblasts in fibrosis imaging of the lung. However, ¹⁸F-labeled 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 [¹⁸F]FAPI-74 prospectively in a small patient cohort. Methods: Eight patients underwent both [¹⁸F]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 between the fibrotic active volume, the Hounsfield scale, as well as the vital and diffusing capacity of the lung. Conclusion: The initial results confirm our assumption that [¹⁸F]FAPI-74 offers a viable non-invasive assessment method for pulmonary fibrotic changes in patients with IPF.