An 18F-FDG-PET/CT-based Radiomics Signature For Estimating Malignance Probability Of Solitary Pulmonary Nodule

Objects:To explore the effect of positron emission tomography（PET）integrated with computed tomography(CT;¹⁸F-FDG-PET/CT)combined with radiomics for predicting probability of malignancy of SPNs.Methods:We retrospectively enrolled 190 patients with SPNs confirmed by pathology from January 2013 to December 2019 in our hospital.SPNs were benign in69 patients and malignant in 121 patients.Patients were randomly divided into a training or testing group at a ratio of 7:3.First,manually segment and outline the region of interest（Region of interest,ROI）in the PET image and the CT image,extract the imaging feature parameters from the ROI,use the ITK-SNAP software to manually outline the 3D ROI of the PET image and the CT image,and import the AK analysis software to extract the image group Use the Lasso regression method to reduce the dimensionality of features,randomly divide the patients into a training group（132 cases）and a test group（58 cases）with the help of IPMS software,and use the SMOTE method for equalization.In the training group,least absolute shrinkage and selection operator regression analyses and Spearman correlation analyses were used to select the strongest radiomics features.PET,CT,and joint models were constructed using multivariate logistic regression analysis.Receiver operating characteristic（Receiver operator characteristic,ROC）curves,calibration curves,and decision curves were plotted to evaluate diagnostic efficiency,calibration degree,and clinical usefulness of all models in training and testing groups.Results:The estimative effectiveness of the joint model was superior to the CT or PET model alone in the training and testing groups.For the joint model,CT model,and PET model,area under the ROC curve was 0.929,0.819,0.833 in the training group,and 0.844,0.759,0.748 in the testing group,respectively.Calibration and decision curves showed good fit and clinical usefulness for the joint model in both training and testing groups.Conclusion:Radiomics models constructed by combining PET and CT radiomics features are valuable for distinguishing benign and malignant SPNs.The combined effect is superior to qualitative diagnoses with CT or PET radiomics models alone.