Predictive value of [18F] fluoro-2-deoxy-D-glucose positron emission tomography for clinical outcome in patients with relapsed/refractory diffuse large B-cell lymphoma prior to and after autologous stem cell transplant

We evaluated the predictive value of [F-18]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for clinical outcome such as progression-free survival (PFS) and overall survival (OS) in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) prior to and after autologous stem cell transplant (ASCT). FDG-PET/computed tomography (CT) was performed in 39 consecutive patients with relapsed/refractory DLBCL scheduled for ASCT. The median follow-up of surviving patients was 3 years (range 19-66 months). Both pre- and post-ASCT, FDG-PET findings were strongly correlated with PFS and OS (p < 0.005). The 2-year PFS estimates for FDG-negative versus -positive patients were 84.8% vs. 36.8% (pre-) and 81.1% vs. 13.3% (post-). The 2-year OS estimates in these groups were 95.5% vs. 68.3% (pre-) and 92.7% vs. 57.1% (post-). Patients were classified into three groups according to FDG-PET results before and after ASCT. The median PFS was significantly lower in the +/+ group (13.0 months) as compared with the +/- group (31.0 months, p = 0.021) and the -/- group (p = 0.000). The regression model showed that the predictive value of FDG-PET before ASCT owed its significance to a very high hazard ratio between patients with positive and negative imaging (p < 0.01). FDG-PET prior to and following ASCT in patients with relapsed or refractory DLBCL contains prognostic information on long-term clinical outcome.