Diagnostic potential of ultrasonography and computed tomography in differentiating cervical lymph node metastasis of thyroid cancer: a systematic review and meta-analysis.

Introduction: Ultrasonography (US) and computed tomography (CT) are the most common diagnostic modalities of cervical lymph node metastasis of thyroid cancer, but few studies have been conducted to compare their diagnostic accuracy, with inconclusive results. Material and methods: Multiple databases including PubMed, Springer, EMBASE, Ovid, and the Cochrane Library were searched with the keywords "thyroid cancer OR thyroid carcinomas", "cervical lymph nodes", "metastatic OR metastasis", and "ultrasonography OR ultrasound OR CT OR computed tomography" in June 2018. Full-text articles comparing diagnostic accuracy of US and CT were reviewed. Meta-analyses were conducted to estimate sensitivity and specificity. The forest plots of sensitivity and specificity and summary receiver operating characteristic curves (SROC) are also presented in this article. Results: Finally, 8 of 1785 studies which eventually met the inclusion criteria were selected in this study. The mean sensitivities and specificities of CT in whole and central cervical areas were 0.65, 0.56 and 0.89, 0.83, respectively, while for US, the sensitivities and specificities were 0.58, 0.39 and 0.89, 0.91, respectively. The area under the curve (AUCs) observed of CT and US in whole, central and lateral cervical areas were 0.79 vs. 0.79, and 0.76 vs. 0.67. Because only a few articles were included in this study, publication bias was not assessed. Conclusions: The diagnostic accuracy of US and CT was comparable. The specificity of these two methods was much higher than the sensitivity.