The value of FDG-PET/CT metabolic parameters and treatment metabolic response in predicting long-term survival of patients with diffuse large B-cell lymphoma

Background: Few trials have been conducted regarding using PET/CT metabolic parameters as a predictor for the long-term survival of patients with lymphoma. The present study aimed to determine the prognostic value of quantitative metabolic parameters based on FDG-PET/CT in predicting 2-year mortality and disease recurrence in patients with diffuse large B-cell lymphoma (DLBCL). Materials and Methods: This cross-sectional study was performed on patients who suffered DLBCL and assessed by FDG-PET/CT. All patients have been scheduled for first-line therapy, including the R-CHOP regimen (Rituximab, Cyclophosphamide, Hydroxydaunomycin, Oncovin, and Prednisone). The records of patients eligible for the study were extracted from the hospital archive. All subjects were followed up for 2 years to assess progression-free survival (PFS) and overall survival (OS). Results: Complete response to treatment was revealed in 80.0%, while the disease was progressive in 5.7% and stable in 2.9%. At the end of 2 years of follow-up, in all groups, five people (14.2%) experienced disease relapse, and one person (2.9%) died. Comparing metabolic parameters of PET/CT between survived and non-survived groups showed no difference between the two groups. Similarly, the median value of pointed metabolic parameters was insignificant between groups with and without disease relapse. The comparison of the treatment metabolic response state between non-survived and survived subgroups showed no difference. However, regarding the metabolic response status according to the presence or lack of recurrence, those with disease recurrence experienced a higher rate of progressive metabolic disease condition. Treatment metabolic non-response status and higher Deauville 5-point score (D5PS) score could effectively differentiate the groups with and without disease recurrence. Conclusion: FDG-PET/CT complete metabolic response can predict longer PFS in patients with DLBCL, but its related metabolic parameters may not predict disease outcome.