Prognostic significance of standardized uptake value on F18-FDG PET/CT in patients with extranodal nasal type NK/T cell lymphoma: A multicenter, retrospective analysis

Objectives: The purpose of this study was to evaluate the value of parameters assessed with F18-flurodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in predicting relapse free survival and overall survival in patients with extranodal nasal type NK/T cell lymphoma. Methods: Thirty-six patients with extranodal nasal type NK/T cell lymphoma, and who underwent PET/CT prior to curative treatment, were enrolled at five institutions. Volumes of interest covering the entire tumor volume were delineated on PET/CT images, and the maximum standardized uptake value (SUVmax), mean SUV (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured using thresholds of 40% of SUVmax. Furthermore, we compared the difference in F18-FDG avidity according to Epstein-Barr virus (EBV) infection status. Results: The SUVmax (p = 0.041) and SUVmean (p = 0.049) in patients who died were higher than the respective values of those who survived. A higher TLG (>45.8) was associated with relapse free survival (HR 7.856, p = 0.034). Ann Arbor stage (III-IV, HR 14.12, p = 0.004), and a higher SUVmax (>12.6, p = 0.024) and SUVmean (>6.4, p = 0.024) were associated with poor survival. However, neither the MTV nor the TLG (volumetric parameters) were significant predictors of death. The PET parameters SUVmax (p = 0.181), SUVmean (p = 0.237), MTV (p = 0.636), and TLG (p = 0.469) did not differ significantly between patients with and without EBV infections. Conclusions: High TLG was the only significant predictive factor on relapse free survival. The SUVmax and SUVmean measured by F18-FDG PET/CT could be significant prognostic factors in patients with extranodal nasal type NK/T cell lymphoma. (C) 2017 Elsevier Inc. All rights reserved.