CIrculating Tumour DNA in Lung Cancer (CITaDeL): Optimizing Sensitivity and Clinical Utility

The study consists of three cohorts of patients initiating a new treatment for their NSCLC. The cohorts of (1) patients starting concurrent chemotherapy and radiation for stage III NSCLC (2) patients with advanced NSCLC starting cytotoxic chemotherapy (with or without pembrolizumab) (3) patients with advanced NSCLC starting palliative radiation therapy. This study aims to study the changes in ctDNA levels following a new treatment in lung cancer patients and to explore if the diagnostic utility of ctDNA testing is improved immediately following treatment when tumour cells are actively dying. It will also examine the changes in ctDNA levels and mutational analysis longitudinally.