Deep learning-based classification of parotid gland tumors: integrating dynamic contrast-enhanced MRI for enhanced diagnostic accuracy.

BACKGROUND: To evaluate the performance of deep learning models in classifying parotid gland tumors using T2-weighted, diffusion-weighted, and contrast-enhanced T1-weighted MR images, along with DCE data derived from time-intensity curves. METHODS: In this retrospective, single-center study including a total of 164 participants, 124 patients with surgically confirmed parotid gland tumors and 40 individuals with normal parotid glands underwent multiparametric MRI, including DCE sequences. Data partitions were performed at the patient level (80% training, 10% validation, 10% testing). Two deep learning architectures (MobileNetV2 and EfficientNetB0), as well as a combined approach integrating predictions from both models, were fine-tuned using transfer learning to classify (i) normal versus tumor (Task 1), (ii) benign versus malignant tumors (Task 2), and (iii) benign subtypes (Warthin tumor vs. pleomorphic adenoma) (Task 3). For Tasks 2 and 3, DCE-derived metrics were integrated via a support vector machine. Classification performance was assessed using accuracy, precision, recall, and F1-score, with 95% confidence intervals derived via bootstrap resampling. RESULTS: In Task 1, EfficientNetB0 achieved the highest accuracy (85%). In Task 2, the combined approach reached an accuracy of 65%, while adding DCE data significantly improved performance, with MobileNetV2 achieving an accuracy of 96%. In Task 3, EfficientNetB0 demonstrated the highest accuracy without DCE data (75%), while including DCE data boosted the combined approach to an accuracy of 89%. CONCLUSIONS: Adding DCE-MRI data to deep learning models substantially enhances parotid gland tumor classification accuracy, highlighting the value of functional imaging biomarkers in improving noninvasive diagnostic workflows.