The added value of contrast-enhanced ultrasound to conventional ultrasound in differentiating benign and malignant solid breast lesions: a systematic review and meta-analysis

•Adding CEUS to conventional US could improve the diagnostic specificity and accuracy for breast cancers, with little reduction of the sensitivity. •The methods of adding CEUS to the conventional US differed among studies and a uniform standard might be needed for further clinical application. •CEUS-rerated BI-RADS might have a higher diagnostic performance in BI-RADS 3–5 lesions. Aim To investigate the added value of contrast-enhanced ultrasound (CEUS) to the conventional ultrasound (US) in the diagnosis of breast lesions. Materials and methods PubMed, EMBASE, and Web of Science were searched for relevant studies published between 24 May 2005, and 29 October 2017. Studies incorporating CEUS into the conventional US were included. The reference standard was set by means of histopathological findings. The quality assessment of diagnostic studies (QUADAS) instrument was used to assess the quality of the included studies. Meta-Disc version 1.4. was used to calculate the sensitivity, specificity, summary receiver-operating characteristic (sROC) curves, and area under the curve (AUC). Meta-regression with Stata 12.0 was used to compare the diagnostic accuracy of the two techniques. Results Five studies, comprising 992 patients, were eligible for this meta-analysis. For conventional US, the pooled sensitivity and specificity for were 0.87 (95% confidence interval [CI]: 0.84–0.91) and 0.80 (95% CI: 0.76–0.84), respectively, the AUC was 0.9049. For CEUS-rerated US, the pooled sensitivity and specificity were 0.93 (95% CI: 0.90–0.95) and 0.87 (95% CI: 0.84–0.90). The AUC was 0.9482. Meta-regression showed the sensitivity of CEUS-rerated US did not differ from conventional US (p=0.29), while specificity showed significant difference (p<0.01). There was evidence of between-study heterogeneity regarding sensitivity and specificity for both assessments. Conclusions Adding CEUS to conventional US could improve the diagnostic performance in differentiating benign from malignant solid breast lesions, whilst retaining high sensitivity, especially in Breast Imaging-Reporting and Data System (BI-RADS) 3–5 lesions. A uniform standard to distinguish benign from malignant lesions might be needed for further clinical application. To investigate the added value of contrast-enhanced ultrasound (CEUS) to the conventional ultrasound (US) in the diagnosis of breast lesions. PubMed, EMBASE, and Web of Science were searched for relevant studies published between 24 May 2005, and 29 October 2017. Studies incorporating CEUS into the conventional US were included. The reference standard was set by means of histopathological findings. The quality assessment of diagnostic studies (QUADAS) instrument was used to assess the quality of the included studies. Meta-Disc version 1.4. was used to calculate the sensitivity, specificity, summary receiver-operating characteristic (sROC) curves, and area under the curve (AUC). Meta-regression with Stata 12.0 was used to compare the diagnostic accuracy of the two techniques. Five studies, comprising 992 patients, were eligible for this meta-analysis. For conventional US, the pooled sensitivity and specificity for were 0.87 (95% confidence interval [CI]: 0.84–0.91) and 0.80 (95% CI: 0.76–0.84), respectively, the AUC was 0.9049. For CEUS-rerated US, the pooled sensitivity and specificity were 0.93 (95% CI: 0.90–0.95) and 0.87 (95% CI: 0.84–0.90). The AUC was 0.9482. Meta-regression showed the sensitivity of CEUS-rerated US did not differ from conventional US (p=0.29), while specificity showed significant difference (p<0.01). There was evidence of between-study heterogeneity regarding sensitivity and specificity for both assessments. Adding CEUS to conventional US could improve the diagnostic performance in differentiating benign from malignant solid breast lesions, whilst retaining high sensitivity, especially in Breast Imaging-Reporting and Data System (BI-RADS) 3–5 lesions. A uniform standard to distinguish benign from malignant lesions might be needed for further clinical application.