Development and validation of a CT-based deep learning radiomics signature to predict lymph node metastasis in oropharyngeal squamous cell carcinoma: a multicentre study

Abstract Objectives Lymph node metastasis (LNM) is a pivotal determinant that influences the treatment strategies and prognosis for oropharyngeal squamous cell carcinoma (OPSCC) patients. This study aims to establish and verify a deep learning (DL) radiomics model for the prediction of LNM in OPSCCs using contrast-enhanced computed tomography (CECT). Methods A retrospective analysis included 279 OPSCC patients from 3 institutions. CECT images were used for handcrafted (HCR) and DL feature extraction. Dimensionality reduction for HCR features used recursive feature elimination (RFE) and least absolute shrinkage and selection operator (LASSO) algorithms, whereas DL feature dimensionality reduction used variance-threshold and RFE algorithms. Radiomics signatures were constructed using six machine learning classifiers. A combined model was then constructed using the screened DL, HCR, and clinical features. The area under the receiver operating characteristic curve (AUC) served to quantify the model’s performance, and calibration curves were utilized to assess its calibration. Results The combined model exhibited robust performance, achieving AUC values of 0.909 (95% CI, 0.861-0.957) in the training cohort, 0.884 (95% CI, 0.800-0.968) in the internal validation cohort, and 0.865 (95% CI, 0.791-0.939) in the external validation cohort. It outperformed both the clinical model and best-performing radiomics model. Moreover, calibration was deemed satisfactory. Conclusions The combined model based on CECT demonstrates the potential to predict LNM in OPSCCs preoperatively, offering a valuable tool for more precise and tailored treatment strategies. Advances in knowledge This study presents a novel combined model integrating clinical factors with DL radiomics, significantly enhancing preoperative LNM prediction in OPSCC.