Deep learning–assisted diagnosis of benign and malignant parotid tumors based on contrast-enhanced CT: a multicenter study

Objectives To develop deep learning–assisted diagnosis models based on CT images to facilitate radiologists in differentiating benign and malignant parotid tumors. Methods Data from 573 patients with histopathologically confirmed parotid tumors from center 1 (training set: n = 269; internal-testing set: n = 116) and center 2 (external-testing set: n = 188) were retrospectively collected. Six deep learning models (MobileNet V3, ShuffleNet V2, Inception V3, DenseNet 121, ResNet 50, and VGG 19) based on arterial-phase CT images, and a baseline support vector machine (SVM) model integrating clinical-radiological features with handcrafted radiomics signatures were constructed. The performance of senior and junior radiologists with and without optimal model assistance was compared. The net reclassification index (NRI) and integrated discrimination improvement (IDI) were calculated to evaluate the clinical benefit of using the optimal model. Results MobileNet V3 had the best predictive performance, with sensitivity increases of 0.111 and 0.207 ( p < 0.05) in the internal- and external-testing sets, respectively, relative to the SVM model. Clinical benefit and overall efficiency of junior radiologist were significantly improved with model assistance; for the internal- and external-testing sets, respectively, the AUCs improved by 0.128 and 0.102 ( p < 0.05), the sensitivity improved by 0.194 and 0.120 ( p < 0.05), the NRIs were 0.257 and 0.205 ( p < 0.001), and the IDIs were 0.316 and 0.252 ( p < 0.001). Conclusions The developed deep learning models can assist radiologists in achieving higher diagnostic performance and hopefully provide more valuable information for clinical decision-making in patients with parotid tumors. Key Points • The developed deep learning models outperformed the traditional SVM model in predicting benign and malignant parotid tumors. • Junior radiologist can obtain greater clinical benefits with assistance from the optimal deep learning model. • The clinical decision-making process can be accelerated in patients with parotid tumors using the established deep learning model.