Prognostic value of total lesion glycolysis of baseline 18F-fluorodeoxyglucose positron emission tomography/computed tomography in diffuse large B-cell lymphoma

PURPOSE We evaluated the prognostic value of total lesion glycolysis (TLG) measured in baseline 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diffuse large B-cell lymphoma (DLBCL) treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). METHODS A total of 91 patients with newly diagnosed DLBCL underwent 18F-FDG PET/CT scans before R-CHOP therapy. Metabolic tumor volume (MTV) was measured with the marginal threshold of normal liver mean standard uptake value (SUVmean) plus 3 standard deviations (SD). TLG was the sum of the products of MTV and SUVmean in all measured lesions. The predictive value was estimated by Log-rank test and Cox-regression analysis. RESULTS Median follow-up was 30 months (range, 5-124 months). The 5-year estimated progression-free survival (PFS) of the low and high TLG group were 83% and 34%, respectively (p<0.001). The 5-year overall survival (OS) of the same groups were 92% and 67%, respectively (p<0.001). Patients with high TLG level were more likely to relapse than those with low TLG level even though they had got complete or partial remission in R-CHOP therapy (40% versus 9%, p=0.012). Multivariate analysis revealed TLG was the only independent predictor for PFS (Hazard ratio=5.211, 95% confidence interval=2.210-12.288, p<0.001) and OS (Hazard ratio=9.136, 95% confidence interval=1.829-45.644, p=0.002). Other factors including MTV, National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) and Ann Arbor Stage were not independently predictive for survivals. CONCLUSION Baseline TLG is the only independent predictor for PFS and OS in DLBCL patients treated with R-CHOP therapy.