[Prognostic value of pretreatment (18)F-FDG PET-CT for patients with advanced diffuse large B-cell lymphoma]

Objective: To investigate the prognostic value of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured by pretreatment (18)F-FDG PET-CT in patients with stage Ⅲ~Ⅳ diffuse large B-cell lymphoma (DLBCL). Methods: Clinical data of 72 DLBCL patients with stage Ⅲ~Ⅳ disease undergoing a pretreatment PET-CT scan were retrospectively analyzed. SUVmax, MTV and TLG values of whole-body tumor were calculated from PET-CT images with a threshold of SUVmax 40% of tumor tissues. The optimal cutoff lines of SUVmax, MTV and TLG were obtained by ROC curve analysis. The Kaplan-Meier method and Log-rank test were used to perform univariate survival analysis, while Cox proportional hazards model was done for multivariate analysis. Results: The SUVmax, MTV and TLG of 72 patients were 21.64, 139.48 cm(3) and 1 413.77, respectively. The areas under the ROC curve (AUC) of SUVmax, MTV and TLG were 0.411 (95%CI=0.279~0.544, P=0.195), 0.688 (95%CI=0.566~0.811, P=0.006) and 0.526 (95%CI= 0.469~0.672, P=0.123), respectively. The median SUVmax (21.64) and TLG(1 413.77) were used as the cutoff lines due to smaller AUC. The cutoff point of MTV was 69.71 cm(3). For DLBCL patients of stage Ⅲ~Ⅳ disease, univariate analysis showed that SUVmax and TLG were not associated with the progression-free survival (PFS) and overall survival (OS) (P>0.05 for all). Multivariate analysis showed that National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) but not MTV was the independent prognostic predictor of PFS and OS (P<0.05 for all). And MTV was not the independent prognostic factor of PFS and OS for stage Ⅲ DLBCL (P>0.05 for all). Conclusions: For DLBCL patients with stage Ⅲ~Ⅳ disease, the prognostic value of SUVmax, MTV and TLG before treatment initiation are undetermined, and these indices cannot be used to predict the prognosis.