Residual Anatomical Disease in Diffuse Large B-Cell Lymphoma Patients With FDG-PET-Based Complete Response After First-Line R-CHOP Therapy: Does It Have Any Prognostic Value?

Objective This study aimed to determine the prognostic value of residual anatomical disease, including its size and reduction relative to baseline, in diffuse large B-cell lymphoma patients who have F-18-fluoro-2-deoxy-d-glucose positron emission tomography-based complete response after first-line R-CHOP therapy. Methods This retrospective study included 47 patients. In patients with computed tomography (CT)-based residual disease, the size of the largest residual lesion (Res(max)) and the sum of the sizes of all residual lesions (Res(total)) were measured, and their reductions relative to baseline (Res(max) and Res(total)) were calculated. Results Patients with high-risk National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) scores had significantly lower progression-free survival (PFS) and overall survival (OS) than patients with low-risk NCCN-IPI scores (P = 0.032 and P = 0.022). In contrast, patients with residual lesions at CT had no significantly lower PFS and OS than those without (P = 0.531 and P = 0.801). In the subpopulation with CT-based residual disease, patients with high Res(max), high Res(total), low Res(max), and low Res(total) had no significantly different PFS and OS than those with low Res(max), low Res(total), high Res(max), and high Res(total) (P = 0.980 and P = 0.790, P = 0.423 and P = 0.229, P = 0.923 and P = 0.893, and P = 0.923 and P = 0.893, respectively). Conclusions The NCCN-IPI retains its prognostic value in diffuse large B-cell lymphoma patients with F-18-fluoro-2-deoxy-d-glucose positron emission tomography-based complete response after first-line R-CHOP therapy. However, the presence of residual anatomical disease, including its size and reduction relative to baseline, has no prognostic value in these patients.