Analyses of PFS according to IPI score. (A) PFS after high-dose radiochemotherapy followed by ASCT and IFN-α maintenance in the subgroup of patients with low-risk IPI. Patients assigned to stem cell transplantation experience significantly longer PFS (log-rank test). (B) PFS after high-dose radiochemotherapy followed by ASCT and IFN-α maintenance in the subgroup of patients with intermediate-risk IPI. Patients assigned to stem cell transplantation experience significantly longer PFS (log-rank test).