In previous studies, we synthesized a PD-L1-targeted molecular probe, ⁶⁸Ga-DPA, and developed a ⁶⁸Ga-DPA injection for clinical research. Preliminary studies demonstrated its favorable safety profile and excellent imaging performance. Leveraging the established strengths of the Department of Nuclear Medicine at Peking Union Medical College Hospital, we now plan to conduct an exploratory PET/CT imaging study in lung cancer patients. This study aims to provide an in vivo, non-invasive, and visualizable technique for detecting PD-L1 expression levels and spatial distribution in tumors. It will further validate the clinical utility of this technology, offering critical diagnostic insights for initial assessment and treatment efficacy evaluation in PD-L1-positive tumor patients undergoing PD-L1-targeted therapies.

Inclusion Criteria:

• Age ≥18 years, regardless of gender.
• Patients clinically confirmed or suspected of lung cancer, with pathological specimens obtainable via biopsy or surgery within the recent 2 months.
• At least one measurable target lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1.
• Expected survival >3 months.

Exclusion Criteria:

• Severe hepatic or renal dysfunction (serum creatinine >3.0 mg/dL or any liver enzyme level ≥5× upper limit of normal).
• Women who are planning pregnancy, pregnant, or breastfeeding.
• Inability to lie supine for 30 minutes.
• Claustrophobia or other psychiatric disorders.
• Intolerance to any clinical procedures in the study.
• Other conditions deemed ineligible by the investigator.