Shear wave elastography for predicting cervical lymph node metastasis in papillary thyroid carcinoma: a systematic review and meta-analysis

Abstract

Abstract Background Papillary thyroid carcinoma (PTC) is a common cancer, and cervical lymph node metastasis influences its prognosis. Ultrasound is standard, but detection of central lymph node metastasis (CLNM) is inconsistent, with sensitivity reported at 10.5–61%. Shear wave elastography (SWE) measures tissue stiffness and may highlight metastatic disease. Methods This systematic review and meta-analysis followed PRISMA 2020 guidelines. Web of Science, PubMed, and Scopus were searched for diagnostic studies assessing SWE-derived stiffness measures to predict CLNM in PTC. Data synthesis was performed in R. Pooled mean differences (MD) in stiffness between metastasis-positive and metastasis-negative groups were calculated using a random-effects model. Results Fifteen studies including approximately 6348 patients or nodules met inclusion criteria. SWE stiffness values were significantly higher in patients with LNM than in those without (MD 6.32; 95% CI 0.31–12.34; p = 0.0409), though heterogeneity was substantial ( I 2 = 93.9%). Pooled diagnostic accuracy showed sensitivity of 0.56 (95% CI 0.44–0.68) and specificity of 0.72 (95% CI 0.62–0.83). Conclusion Higher SWE-measured stiffness is associated with CLNM in PTC; however, its diagnostic performance is limited by low-to-moderate sensitivity, moderate specificity, marked heterogeneity, and the geographic concentration of the available evidence in East Asian cohorts. Therefore, SWE should complement rather than replace conventional ultrasound, and the findings should be interpreted cautiously until validated in more geographically diverse populations.