Contrast-enhanced ultrasound improves specificity of breast cancer diagnoses

Adding contrast-enhanced ultrasound (US) to traditional US could promote better, more sensitive detection and diagnosis of breast lesions, researchers reported in Clinical Radiology this July.

Ultrasound is an important modality for finding breast cancer, first author M. Wubulihasimu, of the First People’s Hospital of Kashigar Region in China, and colleagues wrote—especially in dense-breast populations. But national guidelines dictated by the American College of Radiology’s Breast Imaging-Reporting and Data System (BI-RADS) have prompted needless costs and procedures.

“The ACR BI-RADS has standardized the treatment process and improved the diagnosis efficiency of breast lesions worldwide,” Wubulihasimu et al. said. “However, the low specificity troubles clinicians.”

Color Doppler imaging was a successful addition at first, the authors said, but the method still suffered from low sensitivity to small vessels. Contrast-enhanced ultrasound, which uses a contrast agent to reflect high signals and depict the flow of tumor microvessels, (CEUS) soon emerged as a solution.

“The low specificity of BI-RADS has led to unnecessary concern and biopsy around the world,” Wubulihasimu and co-authors wrote. “It is hopeful that a new technique of ultrasound could improve the specificity with little sacrifice of sensitivity.”

For their work, the researchers scoured the online databases PubMed, EMBASE and Web of Science for past studies that have incorporated CEUS into conventional ultrasound procedure. Five studies with a total of 992 patients were eligible for the meta-analysis, and the quality of diagnostic studies was measured by a QUADAS test.

The pooled sensitivity and specificity for ultrasound in the studies was 0.87 and 0.80, respectively, the authors reported. The same numbers for CEUS-rerated ultrasound were 0.93 and 0.87, suggesting the sensitivity of CEUS-rerated ultrasound and traditional ultrasound were similar, while specificity was significantly improved in the case of contrast-enhanced imaging.

“The present meta-analysis showed that CEUS combined with ultrasound could increase the specificity of the diagnosis of breast lesions significantly and had similar sensitivity, leading to a better diagnostic efficacy than BI-RADS alone,” Wubulihasimu and colleagues wrote. “The variety of the diagnostic method contributed to a significant threshold effect and a considerable level of heterogeneity among the studies.”

The authors said the addition of contrast-enhanced ultrasound to traditional US could improve specificity in distinguishing breast lesions in female patients—but more groundwork needs to be laid.

“Adding CEUS to conventional ultrasound could improve the diagnostic performance in differentiating benign from malignant solid breast lesions, whilst retaining high sensitivity, especially in BI-RADS 3-5 lesions,” they wrote. “A uniform standard to distinguish benign from malignant lesions might be needed for further clinical application.”