Intratumoral Heterogeneity of Pretreatment 18F-FDG PET Images Predict Disease Progression in Patients With Nasal Type Extranodal Natural Killer/T-cell Lymphoma

Purpose: The aim of this study was to investigate whether the textural features of pretreatment F-18-FDG PET images can predict prognosis for nasal type extranodal natural killer/T-cell lymphoma (ENKTL). Materials and Methods: A retrospective analysis of the pretreatment F-18-FDG PET images of the patients with newly diagnosed nasal type ENKTL from 2008 to 2013 was conducted. Progression-free survival (PFS) was the main outcome measure. The primary tumor was identified and then delineated using the 40% maximum standardized uptake value (SUVmax) thresholding method. The textural features of the pretreatment F-18-FDG PET images were extracted. The prognostic significance of the textural features of the PET images were examined using the receiver operating characteristic (ROC) curves and Cox regression analysis. P values <0.05 were considered statistically significant. Results: In total, 17 patients were enrolled, among whom 11 showed disease progression and 6 died from the disease during the median follow-up period of 27.2 months. Dissimilarity and low-intensity short-zone emphasis (LISZE) were identified as independent predictors of PFS by using the ROC curves and multivariate Cox analysis after adjusting for the clinical variables. Conclusions: Dissimilarity and LISZE were the significant predictors of disease progression in patients with nasal type ENKTL and can improve their prognostic stratification.