Abstract:
Objective To explore the efficacy of deep learning methods based on 18F-fluorodeoxyglucose (FDG) PET/CT in distinguishing benign and malignant pulmonary nodules.
Methods Retrospective analysis of clinical data of 223 patients with pulmonary nodules who underwent 18F-FDG PET/CT at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2017 to December 2021, including 137 males and 86 females, with a median age of 56 years and an age range from 26 to 82 years. Patients were randomly divided into the training set and test set at a ratio of 8∶2 using sklearn.model_selection.train_test_split function. Using 1.0, 1.5, and 2.0 as the standardized uptake value (SUV) cut-off values for PET hypermetabolic masks, a multi-modal fusion attention network was constructed based on PET/CT images for distinguishing between benign and malignant pulmonary nodules. A comprehensive model was also constructed by combining deep learning features and clinical features. The Mann-Whitney U test was used to compare the differences between measurement data that do not conform to normal distribution. Count data was compared using Chi square test. Multivariate Logistic regression analysis was conducted to investigate the relationship between variables and histopathological types. Diagnostic efficiency was evaluated using receiver operating characteristic curves.
Results Maximum standardized untake value (SUVmax) (P<0.001), carcinoma embryonic antigen (CEA) levels (P=0.026), and gender (P<0.001) were identified as independent risk factors for the classification of lung nodules. The diagnostic efficacy of the multi-modal fusion attention network was superior to that of the single-modal attention network (area under curve (AUC): 0.780 vs. 0.763, accuracy: 0.800 vs. 0.739, sensitivity: 0.833 vs. 0.767, specificity: 0.733 vs. 0.688, and F1-score: 0.847 vs. 0.793). The differential diagnostic performance of the multi-modal fusion attention network guided by both PET uptake enhancement mask and pulmonary nodule CT mask is best when SUV=1.5, achieving an AUC of 0.831 and an accuracy of 0.844. The combination of imaging and clinical features further improved the diagnostic efficacy (AUC of 0.864 and accuracy of 0.822).
Conclusions The deep learning model based on 18F-FDG PET/CT effectively distinguished benign and malignant pulmonary nodules. Furthermore, the comprehensive model further optimized the diagnostic efficacy.