The prognostic value of the metabolic tumor volume calculated from baseline 18FDG PET/CT in patients with newly diagnosed diffuse large B-cell lymphoma
Background: study of the prognostic role of quantitative indicators for assessing the metabolic activity of the process in patients with newly diagnosed in patient with diffuse large B-cell lymphoma (DLBCL). Patients and methods: metabolic bulk volume (MBV), defined as the metabolic volume of the largest lesion, was retrospectively investigated in 47 patients with DLBCL who underwent baseline pre-treatment 18FDG PET-CT at N.N. Alexandrov National Cancer Center of Belarus. Results: semi-automatically segmented (41% SUVmax) total metabolic tumor volume (TMTV) and MBV underwent receiver operating characteristic analysis, identifying optimal thresholds of 600 cm<sup>3</sup> for the TmTv and 275 cm<sup>3 </sup>for the MBV. According to Cox monovariate analysis, the International prognostic index (IPI) and MBV were predictors for progression-free survival (PFS) (HR 2.9 and 2.8, respectively). At multivariate analysis only IPI was independent predictors for PFS (HR 2.7). In subgroup with low IPI (0-2) higher MBV level was strongly associated with worse prognosis: a 3-year PFS rates in patients with MBV>275 cm<sup>3</sup> and <275 cm<sup>3</sup> were 53,8% and 89,5%, respectively (p=0.01). Conclusion: the baseline MBV can be an efficient tool for the risk stratification of aggressive lymphoma.