Impact of residual FLs on outcome. (A) Example PET and DWI scans for a patient with MM at baseline and after ASCT. Treatment-resistant (residual) FLs are highlighted with blue arrows. Prognostic significance of residual FLs after ASCT detected by DWI alone or PET on (B) progression-free and (C) overall survival. Group comparisons were performed using the log-rank test.