A pair of new research studies offers guidance on when and where to use ultrasound for breast screening. The publications highlight the important advances being made in one of radiology’s most versatile modalities.
Ultrasound is used in developed countries for supplementary breast cancer screening in women who may not be suitable for X-ray-based mammography due to issues like dense breast tissue.
- Ultrasound is also being examined as a primary screening tool in developing regions like China and Africa, where access to mammography may be limited.
But despite growing use, there are still many questions about exactly when and where ultrasound is best employed in a breast screening role – and this week’s studies shed some light.
First up is a study in Academic Radiology in which researchers compared second-look ultrasound to mammography in women with suspicious lesions found on breast MRI.
- Their goal was to find the best clinical path for working up MRI-detected lesions without performing too many unnecessary biopsies.
In a group of 221 women, second-look ultrasound was largely superior to mammography with…
- Higher detection rates for mass lesions (56% vs. 17%).
- A much higher detection rate for malignant mass lesions > 10 mm (89%).
- But worse performance with malignant non-mass lesions (22% vs. 38%).
They concluded second-look ultrasound is a great tool for assessment and biopsy of MRI-detected lesions > 10 mm without calcifications.
- It’s not so great for suspicious non-mass lesions, which might be better sent to mammography for further workup.
Breast ultrasound of non-mass lesions was also the focus of a second study, this one published in Radiology.
- Non-mass lesions are becoming more frequent as more women with dense breast tissue get supplemental screening, but incidence and malignancy rates are low.
So how should they be managed? In a study of 993 women with non-mass lesions found on whole-breast handheld screening ultrasound, researchers classified by odds ratios the factors indicating malignancy…
- Associated calcifications (OR=21.6).
- Posterior shadowing (OR=6.9).
- Segmental distribution (OR=6.2).
- Mixed echogenicity (OR=5.0).
- Larger size (2.6 vs. 1.9 mm).
- Negative mammography (2.8% vs. 29%).
The Takeaway
Ultrasound’s value comes from its high prevalence, low cost, and ease of use, but in many ways clinicians are still exploring its optimal role in breast cancer screening. This week’s research studies should help.
