Prognostic superiority of the National Comprehensive Cancer Network International Prognostic Index over pretreatment whole-body volumetric-metabolic FDG-PET/CT metrics in diffuse large B-cell lymphoma

PurposeThis study aimed to determine the prognostic value of whole-body maximum standardized uptake value (SUVmax), whole-body metabolic tumor volume (MTV), and whole-body total lesion glycolysis (TLG) at pretreatment F-18-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). Materials and MethodsSeventy-three patients with newly diagnosed DLBCL who had undergone FDG-PET/CT before rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisolone (R-CHOP) immunochemotherapy were retrospectively included. All FDG-avid lesions in each patient were segmented using semi-automated software to calculate whole-body SUVmax, whole-body MTV, and whole-body TLG values. Cox regression analyses were used to determine the associations of whole-body SUVmax, whole-body MTV, whole-body TLG, and dichotomized National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) risk group (low risk vs. high risk) with progression-free survival (PFS) and overall survival (OS). ResultsOn univariate Cox regression analysis, only the NCCN-IPI was a significant predictor of PFS (P=0.024), and only the NCCN-IPI and whole-body MTV were significant predictors of OS (P=0.039 and P=0.043, respectively). In the multivariate Cox proportional hazards model, only the NCCN-IPI remained an independent predictive factor of PFS (P=0.024) and OS (P=0.039). ConclusionWhole-body SUVmax, whole-body MTV, and whole-body TLG do not provide any prognostic information in DLBCL beyond that which can already be obtained by the NCCN-IPI. Therefore, the NCCN-IPI remains the most important prognostic tool in this disease.