Fig. 2

One month after CRT/RT was the optimal ctDNA time point to predict patient response. A-B Kaplan-Meier curve of progression-free survival (A) or overall survival (B) stratified by ctDNA detection status at TP2 in the discovery set. C Forest plot of the hazard ratio of various plasma sampling time points based on either progression-free survival (PFS) or overall survival (OS) in the discovery set. Patients with or without brain metastases were analyzed separately. Data are presented as median the +/− 95% CI (confidence interval). D A representative case of a male patient who had stage IIIA SCC and received definitive concurrent CRT. The red arrow indicates the initially diagnosed tumor, which became undetectable after CRT. E Kaplan-Meier curve of overall survival stratified by ctDNA detection status at 1 month post-CRT in the external test cohort. A total of 20 independent stage III NSCLC patients whose plasma samples were collected at baseline, in the fourth week during CRT, and after 1 month of CRT were included in the analysis. F Kaplan-Meier curve of overall survival stratified by ctDNA dynamic changes during disease surveillance in the discovery cohort