[Conventional ultrasound and contrast-enhanced ultrasound for predicting cervical lymph node metastasis in head and neck squamous cell carcinoma].

<b>Objective:</b> To evaluate the diagnostic efficacy of conventional ultrasound combined with contrast-enhanced ultrasound (CEUS) for detecting cervical lymph node metastasis in head and neck squamous cell carcinoma (HNSCC). <b>Methods:</b> This retrospective case control study included 259 patients (249 males and 10 females,aged 40-88 years with a median age of 63 years) who were pathologically diagnosed with HNSCC at the First Affiliated Hospital of Chongqing Medical University from April 2022 to August 2024. A total of 259 lymph nodes were assessed(78 pathologically positive nodes and 181 pathologically negative ones). Receiver operating characteristic (ROC) curves were plotted to compare the diagnostic efficacies of conventional ultrasound combined with CEUS and CT, MRI, or conventional ultrasound for cervical lymph node metastasis. Patients were randomly assigned to a training group (<i>n</i>=208) and a validation group (<i>n</i>=51) (8∶2). Univariate and multivariate Logistic regression were used to analyze the independent risk factors for lymph node metastasis prediction. A nomogram model was constructed based on independent risk factors. The model predictive efficacy was assessed by ROC curve, and model's fit was evaluated by <i>Hosmer-Lemeshow</i> test. <b>Results:</b> The area under the curve (AUC) for conventional ultrasound combined with CEUS in predicting cervical lymph node metastasis in HNSCC was 0.923 (95%<i>CI</i>: 0.880-0.965), which was significantly higher than those for enhanced CT, cervical enhanced MRI, and conventional ultrasound [AUC were 0.820 (95%<i>CI</i>: 0.753-0.886), 0.802 (95%<i>CI</i>: 0.737-0.866), and0.836 (95%<i>CI</i>: 0.774-0.899), respectively].There were no statistically significant differences in clinical data between the two groups (all <i>P</i>>0.05). Univariate Logistic regression analysis showed that, among contrast-enhanced ultrasound features, the centripetal perfusion pattern, irregular perfusion defect type, and uneven distribution of contrast agent were significantly associated with cervical lymph node metastasis (all <i>P</i><0.05). Among conventional ultrasound features, L/S ratio≤1.5, heterogeneous internal echoes, uneven cortex thickening, blurred corticomedullary boundary, loss of lymphatic gate structure, and peripheral or mixed type on color Doppler flow imaging were significantly associated with cervical lymph node metastasis (all <i>P</i><0.05). Multivariate Logistic regression analysis indicated that the centripetal perfusion pattern, heterogeneous internal echoes, and uneven cortical thickening were independent risk factors for cervical lymph node metastasis (all <i>P</i><0.05). A nomogram model was constructed based on the above independent risk factors, and offered an AUC of 0.933 (95%<i>CI</i>:0.890-0.976) in the training group, which was significantly higher than that for enhanced CT, enhanced MRI, conventional ultrasound, and conventional ultrasound combined with CEUS [AUC were 0.818 (95%<i>CI</i>:0.747-0.890), 0.807 (95%<i>CI</i>:0.739-0.875), 0.842 (95%<i>CI</i>: 0.777-0.908), and 0.921 (95%<i>CI</i>:0.876-0.967), respectively]. In the validation group, the AUC was 0.866 (95%<i>CI</i>:0.703-1.000), which was higher than that for cervical enhanced CT, enhanced MRI, and conventional ultrasound [AUC were 0.820 (95%<i>CI</i>:0.613-1.000), 0.711 (95%<i>CI</i>:0.478-0.943), and 0.748 (95%<i>CI</i>:0.515-0.982), respectively]. <b>Conclusion:</b> The combination of conventional ultrasound and CEUS has significant clinical application value in predicting cervical lymph node metastasis in HNSCC.