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

Abstract

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.

Fig. 1

Comparison of AUC values of two OS models (i) including clinical variables only and (ii) including both clinical and PET variables. The latter model had higher AUCs. AUCs, areas under the curve; OS, overall survival.

Fig. 2

Comparison of AUC values of four DFS models, including (i) clinical variables only, (ii) clinical and CT variables, (iii) clinical and PET variables, and (iv) clinical, CT, and PET variables. Model (iv) had the highest AUCs. AUCs, areas under the curve; CT, computed tomography; DFS, disease-free survival.

Fig. 3

Comparison of ROC and AUC of three models for favorable response to chemotherapy: including (i) clinical variables only, (ii) clinical and CT variables, and (iii) clinical, CT, and PET variables. Model (iii) had the highest AUCs. AUCs, areas under the curve; CT, computed tomography; ROC, receiver operating characteristic.