Multi-center validated attention-BiFPN deep learning for CT-based lung cancer subtype classification
摘要
Accurate differentiation between lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) is essential for guiding treatment decisions and predicting outcomes for non-small cell lung cancer (NSCLC). However, CT-based subtype discrimination remains challenging due to overlapping imaging features and inter-observer variability.
MethodsWe developed an improved deep learning framework integrating residual connections, attention mechanisms, and a bidirectional feature pyramid network (BiFPN), combined with an ensemble strategy, to classify NSCLC subtypes on annotated CT slices. A total of 290 patients were retrospectively enrolled from two centers, with 200 used for training and internal validation, and 90 for external testing. Ablation experiments were conducted to evaluate the contribution of each architectural component. Model performance was assessed using F1-score, precision, accuracy, and the area under the receiver operating characteristic curve (AUC). Grad-CAM was applied to provide visual interpretability.
ResultsIn the internal validation cohort, the proposed model achieved an F1-score of 0.9973, precision of 0.9946, accuracy of 0.995, and an AUC of 1.0000, outperforming all benchmark models. In the external test cohort, the model maintained robust generalizability with an F1-score of 0.9508, precision of 0.9667, accuracy of 0.9333, and an AUC of 0.9891, surpassing competing methods. Grad-CAM visualizations demonstrated that the model predominantly focused on radiologically relevant regions, aligning with known imaging features of LUAD and LUSC.
ConclusionsThis study presents a segmentation-guided, interpretable deep learning model for CT-based NSCLC subtype classification. The model may serve as an adjunctive tool for pre-treatment subtype assessment, while further validation using fully automated lesion localization and larger multicenter datasets is warranted before clinical implementation.