This is a prospective exploratory biodistribution study in patients with interstitial lung disease (ILD). The purpose of this research study is to determine where and to which degree the FAPI tracer (68Ga-FAPI-46) accumulates in normal and fibrotic lung tissues of patients with interstitial lung disease. The study will include patients with interstitial lung disease with fibrotic lesions who are scheduled to undergo lung biopsy or transplantation. The study will include 30 patients, the upper limit for PET imaging studies conducted under the Radioactive Drug Research Committee (RDRC) purview. Participants will be injected with up to 7 mCi of 68-GaFAPi and will undergo one PET/CT scan. The study is sponsored by Ahmanson Translational Theranostic Division at UCLA.
PET Study of 68Ga-FAPi-46 in Patients With Interstitial Lung Disease: an Exploratory Biodistribution Study With Histopathology Validation.
ILD is a group of respiratory diseases that affect the interstitium of the lungs. A major problem is the highly variable course of fibrosing ILD: some patients remain stable without treatment, and others progress rapidly despite pharmacotherapy. Novel diagnostic approaches for risk stratification with more accurate prediction of the course of fibrosing ILD could potentially improve prognostication and ultimately lead to better survival in these patients. Persistent activation and local accumulation of myofibroblasts is a common feature of fibrotic diseases. FAP is a promising target for molecular imaging of fibroblast activation and detection of sites of active tissue remodeling. Small molecule inhibitors of FAP have been labeled with positron-emitting isotopes for PET imaging. 68Ga-FAPi-46 can serve as diagnostic biomarker in ILD. In this study, the investigators will evaluate the 68Ga-FAPi-46 biodistribution in patients with ILD and observe the correlation of FAP expression and FAPi radiopharmaceutical uptake. The primary objective of this study is to evaluate the biodistribution of the new FAP-targeted PET tracer, 68Ga-FAPi- 46, in patients with ILD who are scheduled for lung biopsy or transplantation. The biodistribution will be validated by histopathology and immunohistochemistry from obtained lung tissue. OUTLINE: 1. Participants with Interstitial Lung Disease will be asked to undergo a 68Ga-FAPi-46 PET/CT 2. Patients will be followed until pathology is obtained during clinical care. 3. Biodistribution results will be assessed comparing pathological findings and PET/CT results