A Clinical Imaging Study of the Changes in [18F]F-AraG Uptake Following Anti-PD-1 Therapy in Non-small Cell Lung Cancer

Inclusion Criteria: * Histologically confirmed NSCLC, a histological biopsy is mandatory, negative for epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutations * Be willing to provide either archival biopsy or fresh biopsy at screening. * Stage IIIB-IV patients that are planned to be treated with anti-PD-1 monotherapy * High PD-L-1 expression (≥50% TPS) * No prior systemic therapy for the treatment of cancer * Be willing and able to provide written informed consent for the trial. * Have a performance status of 0-2 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale * Be above 18 years of age on day of signing informed consent. Exclusion Criteria: * Subjects with a condition requiring systemic treatment with either corticosteroids (\> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days of day 0. Inhaled or topical steroids, and adrenal replacement steroid \>10 mg daily prednisone equivalent, are permitted in the absence of active autoimmune disease. * Untreated or symptomatic brain metastases * Additional malignancy that is progressing or requires active treatment. Exceptions include basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy. * Evidence of interstitial lung disease or active, non-infectious pneumonitis. * Active infection requiring systemic therapy. * A history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies). * Active Hepatitis B or C. * Psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial. * Patient is pregnant or breastfeeding or expecting to conceive within the projected duration of the trial, starting with the screening visit through 12 weeks after the last administration of \[18F\]F-AraG.