This is an open-label positron emission tomography/computed tomography (PET/CT) study to investigate the diagnostic performance and evaluation efficacy of 68Ga-NOTA-PRGD2 in lung injury (LI) and pulmonary fibrosis (PF) patients. A single dose of nearly 111 MBq 68Ga-NOTA-PRGD2 (≤ 40 µg NOTA-PRGD2) will be intravenously injected into patients with LI/PF. Visual and semiquantitative method will be used to assess the PET/CT images.

The αvβ3-integrin is a transmembrane heterodimeric receptor that mediates cell-cell and cell-extracellular matrix adhesion. The αvβ3-integrin plays a pivotal role in promoting and sustaining angiogenesis and fibrosis. Cyclic arginine-glycine-aspartic acid (RGD) peptide is the key integrin recognition motif that can strongly bind to the αvβ3-integrin, which makes the RGD-based peptides hold a promise for imaging and treatment of diseases characterised with angiogenesis and fibrosis including LI and PF.

Animal study in bleomycin induced lung fibrosis showed good uptake ratio of 68Ga-NOTA-PRGD2 in lung vs background. For interests in clinical translation of 68Ga-NOTA-PRGD2, an open-label dynamic whole-body PET/CT study was designed to investigate safety and diagnostic performance of 68Ga-NOTA-PRGD2 in patients with LI or PF.

Inclusion Criteria:

Patients with idiopathic pulmonary fibrosis

• Males and females, ≥18 years old.
• Characteristic clinical signs, symptoms and laboratory tests suggesting the diagnosis of LI/PF.
• The diagnosis of IPF is based on The Centres for Disease Control and Prevention (CDC) criteria for diagnosing LI/PF. They rely on a combination of clinical, radiological, operative and histological findings, in addition to results of other laboratory tests.

Exclusion Criteria:

• Females planning to bear a child recently or with childbearing potential.
• Renal function: serum creatinine >3.0 mg/dL (270 μM/L).
• Liver function: any hepatic enzyme level more than 5 times upper limit of normal.
• Known severe allergy or hypersensitivity to IV radiographic contrast.
• Patients not able to enter the bore of the PET/CT scanner.
• Inability to lie still for the entire imaging time because of cough, pain, etc.
• Inability to complete the needed examinations due to severe claustrophobia, radiation phobia, etc.
• Concurrent severe and/or uncontrolled and/or unstable other medical disease that, in the opinion of the investigator, may significantly interfere with study compliance.