Diagnostic Performance of Elastography in Malignant Soft Tissue Tumors: A Systematic Review and Meta-analysis

Malignant soft tissue tumors (STTs) are often mistaken for benign tumors, leading to inappropriate treatment including unplanned resection. Elastography, as a non-invasive measurement of tissue mechanical properties, makes use of the different soft tissue elasticity in diverse pathologies to generate information that can be used for diagnostic purposes. Elastography for STTs carries important information that is helpful in differentiating malignant and benign masses. The present study was undertaken to systematically review existing trials on the reliability of elastography in assessment of malignant STTs. A comprehensive literature exploration of the PubMed, EMbase and China National Knowledge Infrastructure databases was conducted for published articles involving the application of elastography in distinguishing malignant STTs. The diagnostic performance of elastography was evaluated with pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the summary receiver operating characteristic curve. Publication bias was also evaluated. This meta-analysis enrolled 18 eligible studies with a total of 1420 patients. The overall number of reported STTs was 1569, of which 478 were classified as positive and 1091 as negative at elastography. The pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of elastography were 0.82 (95% confidence interval: 0.74-0.87), 0.80 (0.71-0.86), 3.99 (2.65-6.01) and 0.23 (0.15-0.34), respectively. The diagnostic odds ratio and area under the curve were 17.36 (8.28-36.38) and 0.88 (0.84-0.90), respectively (Glas et al. 2003). The results of meta-regression analysis revealed that the total number of patients and prevalence of malignant STTs were significant factors in sensitivity, and the year of publication, total number of patients and index test were significant factors affecting study heterogeneity for specificity (p < 0.05). No significant publication bias was observed. This meta-analysis indicates that ultrasound elastography achieves relatively good performance in discriminating between malignant and benign STTs. Nevertheless, further research is needed to verify this finding.