Ultrasound and DBT Screening — Time to Call It Quits?

Ultrasound long ago carved out a role in breast cancer screening as a complementary tool to conventional 2D mammography. But is ultrasound still needed, now that U.S. breast screening programs have largely switched over to 3D digital breast tomosynthesis (DBT)? A new study in Academic Radiology raises questions. 

Conventional 2D mammography has well-known shortcomings, particularly in women with dense breast tissue that can obscure lesions. So alternative modalities like ultrasound, breast MRI, and contrast-enhanced mammography (CEM) are called in to help when needed.

  • Past research has shown that supplemental ultrasound can improve the cancer detection rate (CDR) in a 2D mammography screening program by 3-4 cancers per 1k women. 

But those studies were performed before the switch to DBT, which can often see around overlapping structures thanks to a gantry head that acquires multiple images as it pans across the breast. 

  • So is ultrasound still needed in screening programs using DBT? Researchers from Weill Cornell Medicine at New York-Presbyterian Hospital tested the hypothesis by examining 103k screening exams from 2014 to 2024 in which both DBT and ultrasound were used. 

In the study, researchers found that screening ultrasound after a negative DBT result…

  • Generated 1.9k biopsies, or 19 biopsies for every cancer the modality detected.
  • Produced an additional cancer detection rate of 1.0 per 1k women, compared to an additional CDR of 3-4 cancers for ultrasound in the 2D mammography era. 
  • Had an overall false-positive screening rate of 98.5%, a false-positive biopsy rate of 94.8%, and a positive predictive value of biopsies performed (PPV3) of just 5.2%.
  • Generated $652k false-positive screening ultrasound costs and $1.16M in ultrasound-guided biopsy costs.

The numbers are sobering and indicate that the days of ultrasound as a supplemental screening modality to DBT screening could be coming to a close. 

  • Instead, the researchers recommended that ultrasound screening be replaced by more sensitive modalities like breast MRI or CEM, both of which are fortunately more available now than during the 2D mammography era.

The Takeaway

The new study answers the question – in the negative – of whether supplementary ultrasound is still needed in the era of DBT screening. The positive subtext here is that the research confirms the improved detection performance of 3D compared to 2D mammography.

Studies Support Breast Ultrasound for Screening

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.

iSono Health’s Wearable Breast Ultrasound

iSono Health announced the FDA clearance of its ATUSA automated wearable 3D breast ultrasound system, a first-of-its-kind device that taps into some of the biggest trends in imaging.

The wearable ATUSA system automatically captures the entire breast volume, producing standardized/repeatable breast ultrasound exams in two minutes without requiring a trained operator. The scanner combines with iSono’s ATUSA Software Suite to support real-time 2D visualization, advanced 3D visualization and localization, and AI integration (including iSono’s forthcoming AI tools). That positions the ATUSA for a range of interesting use cases:

  • Enhancing routine exams in primary care and women’s health clinics
  • Expanding breast imaging access in developing countries
  • Supporting longitudinal monitoring for higher-risk women
  • Allowing remote breast cancer monitoring

iSono might have to overcome some pretty big biases regarding how and where providers believe breast exams are supposed to take place. However, the ATUSA’s intended use cases and value propositions have already been gaining momentum across imaging.

  • The rapid expansion of handheld POCUS systems and AI guidance solutions has made ultrasound an everyday tool for far more clinicians than just a few years ago.
  • Wearable imaging continues to be an innovation hotspot, including a range of interesting projects that are developing imaging helmets, patches, and even a few other wearable breast ultrasound systems.
  • There’s a growing focus on addressing the developing world’s imaging gap with portable imaging systems.
  • We’re seeing greater momentum towards technology-enabled enhancements to routine breast exams, including Siemens Healthineers’ recent move to distribute UE LifeSciences’ iBreastExam device (uses vibrations, not imaging).
  • At-home imaging is becoming a far more realistic idea, with commercial initiatives from companies like Butterfly and Pulsenmore in place, and earlier-stage efforts from other breast ultrasound startups. 

The Takeaway

iSono Health has a long way to go before it earns an established role in breast cancer pathways. However, the ATUSA’s use cases and value proposition are well aligned with some of imaging’s biggest trends, and there’s still plenty of demand to improve breast imaging access and efficiency across the world.

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