Abstract
OBJECTIVES: The aim of this study is to evaluate the potential of [(18)F]FDG-PET/CT in terms of prognostic value and treatment monitoring in relapsed / refractory diffuse large B-cell lymphoma (DLBCL)-patients treated with chimeric antigen receptor T-cell (CAR-T) therapy. MATERIAL & METHODS: Forty-eight [(18)F]FDG-PET/CT scans, acquired at pre-defined time points (t(0) - t(2)) of 18 DLBCL-patients (mean age: 60 ± 12 years) treated with CAR-T cell therapy were retrospectively enrolled. Median time of follow-up was ten months (IQR 6-16) following CAR-T cell infusion. SUV(max), sum of the product of diameters (SPD), Deauville score (DS) and Lugano classification (LC) were evaluated. Clinical parameters (age, sex) were obtained. Survival time analyses for progression-free survival (PFS) and overall survival (OS) were calculated, the latter by using the Kaplan-Meier method and Cox regression including a hazard ratio (HR). P values below 0.05 were defined as statistically significant. 95 %-confidence intervals (CI) were calculated. RESULTS: Patients with a SUV(max)> 9.0 at t(0) (median as threshold value) had a significantly shorter PFS (p = 0.04) and OS (p < 0.01). According to LC, a progressive disease (PD) at t(1) (p = 0.02) and t(2) (p < 0.01) was correlated with a reduced OS. SUV(max) > 9.0 at t(0) (p = 0.03, HR = 7.0, CI: 1.3-40.5) and DS > 3 at t(1) (p = 0.04, HR = 8.2, CI: 1.1-61.3) were associated with an increased risk of a PD. CONCLUSION: SUV(max) of [(18)F]FDG-PET/CT seems to be useful as a prognostic marker in DLBCL-patients undergoing CAR-T cell therapy. Furthermore, scores of clinical established Deauville classification and Lugano response criteria acquired at post-CAR-T [(18)F]FDG-PET/CT might be an indicator for early therapy failure.