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?

Abstract

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 18F-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<inf>max</inf>) and the sum of the sizes of all residual lesions (Res<inf>total</inf>) were measured, and their reductions relative to baseline (ΔRes<inf>max</inf> and ΔRes<inf>total</inf>) 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<inf>max</inf>, high Res<inf>total</inf>, low ΔRes<inf>max</inf>, and low ΔRes<inf>total</inf> had no significantly different PFS and OS than those with low Res<inf>max</inf>, low Res<inf>total</inf>, high ΔRes<inf>max</inf>, and high ΔRes<inf>total</inf> (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 ¹⁸F-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.