Abstract
OBJECTIVE: High-dose chemotherapy (HDC) followed by autologous hematopoietic stem cell transplantation (auto-HSCT) plays an important role in improving outcomes of diffuse large B cell lymphoma (DLBCL) patients. (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) has been widely accepted in response assessment and prediction of prognosis in DLBCL. Here, we report the value of (18)F-FDG PET/CT pre- and post-HSCT in predicting outcomes of patients with DLBCL. METHODS: DLBCL patients who had PET/CT scan before and after HSCT were included. PET results were interpreted based upon Deauville criteria. The prognostic value of (18)F-FDG PET/CT in auto-HSCT was evaluated. RESULTS: Eighty-four patients were enrolled. In univariate analysis, pre- and post-HSCT PET findings were correlated with 3-year progression-free survival (PFS) [hazard ratio (HR)=4.391, P=0.001; HR=7.607, P<0.001] and overall survival (OS) (HR=4.792, P=0.008; HR=26.138, P<0.001). Patients receiving upfront auto-HSCT after first-line treatment had better outcomes than relapsed/refractory DLBCL patients (3-year PFS, P<0.001; 3-year OS, P<0.001). In the relapsed/refractory patients, pre- and post-HSCT PET findings were also associated with 3-year PFS (P=0.003vs. P<0.001) and OS (P=0.027vs. P<0.001). A significant correlation was observed between clinical response to chemotherapy before auto-HSCT and outcomes of patients in the entire cohort (3-year PFS, P<0.001; 3-year OS, P<0.001) and in the subgroup of 21 patients with positive pre-HSCT PET (3-year PFS, P=0.084; 3-year OS, P=0.240). A significant association between survival and post-HSCT PET findings was observed in multivariate analysis (HR=5.168, P<0.001). CONCLUSIONS: PET results before and after HSCT are useful prognostic factors for DLBCL patients receiving HSCT. Patients who responded to chemotherapy, even those with positive pre-HSCT PET, are appropriate candidates for auto-HSCT.