Plasma cfDNA Testing Guiding the Treatment Decisions of DLBCL

This study is initiated by researchers and is a prospective, single-center, randomized, clinical controlled study. The study subjects are newly diagnosed DLBCL patients with plasma cfDNA positivity (defined as positive for point mutations, CNV, IgH-related fusion, or IG clonal rearrangement). After achieving complete metabolic remission (Lugano response assessment criteria) following 6 cycles of R-CHOP-like chemotherapy, patients undergo plasma cfDNA testing upon enrollment. Plasma cfDNA-negative patients (Group 1) continue to receive monotherapy with rituximab for 2 cycles, while plasma cfDNA-positive patients are randomly assigned to Group 2 and Group 3. Group 2 patients continue monotherapy with rituximab for 2 cycles, and Group 3 patients receive the original regimen for 2 cycles. Plasma cfDNA testing is performed again for all three groups after completion of the entire treatment. Patient progression-free survival (PFS) is observed for 2 years. After treatment completion, follow-up visits are scheduled every 3 months for a total of 24 months. Research Objective: Evaluate the efficacy and prognosis differences between precision treatment based on plasma cfDNA testing results and the current conventional diagnostic and treatment practices for DLBCL patients. Expected Results: Determining subsequent treatment based on plasma cfDNA MRD results at the end of DLBCL patient treatment is expected to aid in identifying high-risk patients for early relapse and improving their prognosis.