Abstract
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Purpose: To evaluate the prognostic value of interim positron emission tomography/computed tomography (i-PET/CT) obtained after two chemotherapy cycles interpreted using the Deauville 5-point score (PS) in patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).
Methods: The institutional review board approved this study and waived the requirement for informed consent. This retrospective study involved 206 patients with histologically proven untreated DLBCL. All i-PET/CT images were reviewed by three nuclear medicine doctors using the Deauville 5-PS. Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test.
Results: Median follow-up time was 60 months (range: 5-98 months). The overall response rate (ORR), complete response rate (CRR), five-year overall survival (OS) and progression-free survival (PFS) for the whole cohort were 79.1%, 65.5%, 71.4% and 41.7%, respectively. After i-PET/CT revision, 110, 48, and 48 of 206 patients were scored Deauville 1-3PS, 4PS and 5PS, respectively. Patients who scored with Deauville 1-3PS had better outcomes than those with Deauville 4PS and 5PS points (ORR: 97.3% vs. 87.5% vs.29.2%, P < 0.001; CRR: 95.5% vs. 50.0% vs.12.5%, P < 0.001; 5y-OS: 86.4% vs. 72.9% vs.35.4%, P < 0.001; 5y-PFS: 58.2% vs. 33.3% vs.12.5%, P < 0.001 ). v I-PET/CT performed after two cycles R-CHOP interpreted using the Deauville 5-PS is effective for interim therapeutic evaluation during treatment in DLBCL patients. Patient with Deauville 4-PS has a worse outcome than score 1-3, but has a significantly better survival than score 5; only score 5 is associated with poor outcome.