Outcome after relapse by time to relapse, stage at relapse, and type of salvage therapy. OS from the day of first relapse for all relapsing patients (left) and for the DLBCL subgroup (right) in relation to the time to first relapse from iPET evaluation (top), the Ann Arbor stage at first relapse (middle), and the type of salvage therapy. The type of salvage therapy was defined on the basis of the entire disease course (up to 7 lines of salvage therapy), including (1) supportive care alone; (2) chemotherapy, immunotherapy, and/or radiotherapy with or without supportive care, but without transplantation; (3) high-dose chemotherapy with auto-SCT with or without chemotherapy, immunotherapy, radiotherapy or supportive care, but without allogeneic transplantation; and (4) allogeneic transplantation with or without autologous transplantation, chemotherapy, immunotherapy, radiotherapy, or supportive care. Chemotherapy/immunotherapy alone, radiotherapy alone, and chemotherapy/immunotherapy consolidated by radiotherapy were combined in 1 group, because outcome after first relapse did not significantly differ among these modalities (supplemental Figure 5). Pairwise comparisons of treatment types were statistically significant (P < .001 to P = .049), except for autologous vs allogeneic transplantation (P = .225 for all relapsing patients, P = .791 for the DLBCL subgroup). The numbers in parentheses represent 95% CIs. No., number; p, log-rank test.