Idiopathic pulmonary fibrosis refers to a specific form of chronic fibrous interstitial pneumonia that occurs spontaneously, limited to the lung, and shows features of usual interstitial pneumonia on high resolution computed tomography and histological examination. Radionuclide labeled FAPI has been developed as a new tracer for tumor and inflammatory lesions imaging. Recent studies have shown that FAPI PET/CT imaging is a promising new imaging method for pulmonary fibrosis. HFAPI is obtained by conjugating 99mTc-chelator moiety (6-hydrazinonicotinamide, HYNIC) with FAP targeting moiety. The aim of this study is to investigate the location and extent of 99mTc labeled FAPI tracer (99mTc-HFAPI) in normal and fibrotic lung tissue of patients with pulmonary fibrosis, and to explore the clinical significance of 99mTc-HFAPI SPECT/CT in the diagnosis, treatment response evaluation and follow-up of pulmonary fibrosis.
This prospective study will investigate the potential usefulness of 99mTc labeled FAPI SPECT/CT in the diagnosis, treatment response assessment, and follow-up of pulmonary fibrosis.