The Role of Consolidative Radiotherapy after a Complete Response to Chemotherapy in the Treatment of Diffuse Large B-Cell Lymphoma in the Rituximab Era: Results from a Systematic Review with a Meta-Analysis

Abstract

Background: The current standard therapy for patients with diffuse large B-cell lymphoma (DLBCL) is rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (RCHOP). The role of radiotherapy (RT) after complete response (CR) to RCHOP in patients with DLBCL remains unclear. This systematic review with a meta-analysis is an attempt to evaluate this role. Methods: Studies that evaluated RT versus no-RT after CR to RCHOP for DLBCL patients were searched in databases. Hazard ratios (HR) with their respective 95% confidence intervals (CI) were calculated using a random-effects model. Results: A total of 4 qualified retrospective studies (633 patients) were included in this review. The results suggested that RT improved overall survival (OS; HR 0.33, 95% CI 0.14-0.77) and progression-free/event-free survival (PFS/EFS; HR 0.24, 95% CI 0.11-0.50) in all patients compared with no-RT. In a subgroup analysis of patients with stage III-IV DLBCL, RT improved PFS/EFS (HR 0.19, 95% CI 0.07-0.51) and local control (HR 0.12, 95% CI 0.03-0.44), with a trend of improving OS (HR 0.35, 95% CI 0.12-1.05). Conclusion: Consolidation RT could significantly improve outcomes of DLBCL patients who achieved a CR to RCHOP. However, the significance of these results was limited by these retrospective data. Further investigation of the role of consolidation RT in the rituximab era is needed.