Highlights • FDG-PET has been shown to predict short-term outcomes with anti-PD1 therapy better than CT • At 5-years, patients with complete metabolic response (CMR) on 1-year PET had sustained responses (PFS 90%) • This was greater in those with complete response (PFS 93%), as most patients with partial response have CMR (PFS 88%) • In the minority that progress, often in solitary sites and managed locally, overall survival remains excellent • PET may have utility in predicting long-term...