Figure 4. The Post-treatment PET outcomes is a powerful tool to stratify patients’ OS and DFS. Kaplan-Meier survival analysis of post-treatment PET-outcome-defined risk levels in the training, validation cohorts and combined cohort. OS: the training cohort (A), validation cohort (B), and combined cohort (C). DFS: the training cohort (D), validation cohort (E), and combined cohort (F). Abbreviations: OS: overall survival. DFS: disease free survival.