Zhao H, et al. - Up to September 2017, researchers searched PubMed, EMBASE and Cochrane Library databases to determine the performance of preoperative ultrasound in the diagnosis of cervical lymph node metastases (CLNM) of papillary thyroid cancer (PTC) and its ability to aid with cervical lymph node dissection (CLND). To evaluate the diagnostic effectiveness of ultrasound in detecting central and lateral CLNM of PTC, overall sensitivity, specificity, and diagnostic odds ratio (DOR) were used. In the meta-analysis, 19 studies with 4,014 subjects were included. The pooled sensitivity, specificity, DOR and area under curve (AUC) of ultrasound in identifying central CLNM were 0.33, 0.93, 5.63, and 0.69, respectively and lateral CLNM were 0.70, 0.84, 18.7 and 0.88, respectively. Overall, they found that preoperative ultrasound shows poor sensitivity in the diagnosis of central CLNM and good diagnostic effectiveness for lateral CLNM of PTC. Due to the high incidence of central CLNM and the low diagnostic effectiveness of ultrasound, prophylactic central CLND is suggested for PTC patients.