Combination of FDG PET/CT radiomics and clinical parameters for outcome prediction in patients with non-Hodgkin's lymphoma.

Purpose: The purposes was to build model incorporating PET +  computed tomography (CT) radiomics features from baseline PET/CT + clinical parameters to predict outcomes in patients with non-Hodgkin lymphomas.

Methods: Cohort of 138 patients with complete clinical parameters and follow up times of 25.3 months recorded. Textural analysis of PET and manual correlating contouring in CT images analyzed using LIFE X software. Defined outcomes were overall survival (OS), disease free-survival, radiotherapy, and unfavorable response (defined as disease progression) assessed by end of therapy PET/CT or contrast CT. Univariable and multivariable analysis performed to assess association between PET, CT, and clinical.

Results: Male ( P  = 0.030), abnormal lymphocytes ( P  = 0.030), lower value of PET entropy ( P  = 0.030), higher value of SHAPE sphericity ( P  = 0.002) were significantly associated with worse OS. Advanced stage (III or IV, P  = 0.013), abnormal lymphocytes ( P  = 0.032), higher value of CT gray-level run length matrix (GLRLM) LRLGE mean ( P  = 0.010), higher value of PET gray-level co-occurrence matrix energy angular second moment ( P  < 0.001), and neighborhood gray-level different matrix (NGLDM) busyness mean ( P  < 0.001) were significant predictors of shorter DFS. Abnormal lymphocyte ( P  = 0.033), lower value of CT NGLDM coarseness ( P  = 0.082), and higher value of PET GLRLM gray-level nonuniformity zone mean ( P  = 0.040) were significant predictors of unfavorable response to chemotherapy. Area under the curve for the three models (clinical alone, clinical + PET parameters, and clinical + PET + CT parameters) were 0.626, 0.716, and 0.759, respectively.