Abstract

Objective: To study the value of ultrasound (US) in diagnosing cervical lymph node metastasis in patients (pts) with thyroid carcinoma (TC) before surgery by comparing it with the pathology results of cervical lymph nodes after surgery. Subjects and Methods: A retrospective study from January 2019 to December 2023. A total of 313 pts underwent TC surgery at FV Hospital, Ho Chi Minh City. 197 pts were excluded due to no cervical lymph node detected on US and/or non lymph node on thyroid tissue operated. 116 patients were selected for the study with the following criteria: confirmed diagnosis of TC based on fine-needle aspiration (FNA) or core biopsy, US evaluation of cervical lymph node metastasis before surgery according to the lateral cervical node regions (groups I, II, III, IV, V) and central node group (group VI) and post-surgical histopathology of cervical lymph nodes for comparison with pre-surgical US results. The diagnostic value of US for all cervical lymph node groups combined, as well as for the lateral and central lymph node groups, was determined by calculating the following indicators: accuracy, sensitivity (Sen), specificity (Spe), positive predictive value (PPV), negative predictive value (NPV), and area under the ROC curve (AUC). Results: Female/ male ratio = 3.3/1 (89/27 pts). The average age was 43 ± 12.41. The metastasis rate: 49.1% for all cervical lymph nodes, 44.8% for the central cervical lymph node group. The diagnostic value of US for cervical lymph node metastasis was: acceptable for all cervical lymph node groups combined with an accuracy of 0.71(95% CI: 0.70 - 0.71), Sen 0.46 (95% CI: 0.44 - 0.46), Spe 0.95 (95% CI: 0.94 - 0.95), PPV 0.89 (95% CI: 0.89 - 0.90), NPV 0.64 (95% CI: 0.63 - 0.65), and AUC 0.70 (95% CI: 0.6 - 0.8); very good for the lateral cervical node group: accuracy 0.96 (95% CI: 0.96–0.97), Sen 0.96 (95% CI: 0.95–0.96), Spe 0.97(95% CI: 0.96 - 0.97), PPV 0.89 (95% CI: 0.88 - 0.89), NPV 0.98 (95% CI: 0.98 - 0.99), AUC 0.94 (95% CI: 0.8 - 1.0); and weak for the central cervical node group: accuracy 0.58 (95% CI: 0.57 - 0.59), Sen 0.11 (95% CI: 0.11 - 0.12), Spe 0.96 (95% CI: 0.96 - 0.97), PPV 0.75 (95% CI: 0.74 - 0.76), NPV 0.57 (95% CI: 0.56 - 0.58), and AUC 0.66 (95% CI: 0.5 - 0.8). Conclusion: US is a good diagnostic tool for detecting lateral cervical lymph node metastasis in TC. The ability to detect cervical lymph node metastasis is very low for the central node group.