Total lesion glycolysis in positron emission tomography is a better predictor of outcome than the International Prognostic Index for patients with diffuse large B cell lymphoma

Abstract

BACKGROUND: This study was undertaken to evaluate the prognostic value of quantitative metabolic parameters in [18F]2-fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) for diffuse large B cell lymphoma (DLBCL). METHODS: A total of 140 DLBCL patients underwent FDG-PET scans before rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy. The maximal standardized uptake value (SUVmax) and total lesion glycolysis (TLG) were calculated, with the margin thresholds as 25%, 50%, and 75% of SUVmax of all lesions. Treatment outcomes were compared between groups according to metabolic parameters and the International Prognostic Index (IPI). RESULTS: After a median follow-up of 28.5 months (range, 5-81 months), the 2-year progression-free survival (PFS) and overall survival (OS) were 83% and 87%, respectively. Among metabolic parameters, TLG at the threshold of 50% (TLG50) was significantly associated with treatment outcomes. High TLG50 values (>415.5) were associated with reduced survivals compared with low TLG50 values (415.5) (2-year PFS of 73% versus 92%, P = .007; and 2-year OS of 81% versus 93%, P = .031). High IPI score (3) significantly reduced OS (2-year OS of 79% versus 90%, P = .049). Ann Arbor stage III/IV adversely affected PFS (P = .013). However, high IPI score and Ann Arbor stage of III/V did not significantly shorten PFS (P = .200) and OS (P = .921), respectively. High TLG50 values independently predicted survivals by multivariate analysis (hazard ratio = 4.4; 95% confidence interval = 1.5-13.1; P = .008 for PFS and hazard ratio = 3.1; 95% confidence interval = 1.0-9.6; P = .049 for OS). CONCLUSIONS: Combined assessment of volume and metabolism (ie, TLG) is predictive of survivals in DLBCL patients who are treated with R-CHOP. Cancer 2013. (c) 2012 American Cancer Society.