Embargoed for 9/23/2025, 7 a.m. PT – Adding MBI to DBT finds more breast cancers

Adding molecular breast imaging (MBI) to digital breast tomosynthesis (DBT) screening leads to more invasive cancers being found in women with dense breasts, according to results published September 23 in Radiology

Researchers led by Carrie Hruska, PhD, from the Mayo Clinic in Rochester, MN, found that adding MBI to DBT screening increased cancer detection by 2.5-fold and led to modestly increased recall rates at the second screening round. 

“We think that adding a supplemental technique … will help reduce the presentation of advanced cancer,” Hruska told AuntMinnie.com. “MBI did really well in this study in taking out advanced and interval cancers. Altogether, it would not be something that would replace DBT, but together, they work really well.” 

While MRI is recommended for women with dense breasts, barriers such as lack of access, higher cost, and patient intolerance may prevent these women from receiving adequate supplemental breast screening.  

The National Comprehensive Cancer Network (NCCN) endorses the use of contrast-enhanced mammography (CEM) and MBI as suitable alternatives for women who qualify for supplemental screening but cannot undergo MRI. 

MBI reveals cancers hidden from mammography in dense breasts by using a radiotracer, technetium 99m sestamibi. Hruska and colleagues studied the performance of screening MBI as a supplement to DBT in women with dense breasts. They presented results from the Density Molecular Breast Imaging and Tomosynthesis to Eliminate the Reservoir (MATTERS) trial. 

Carrie Hruska, PhD, talks about the promise that MBI holds for breast cancer screening.

The prospective study included 2,978 women with dense breasts from five study sites. The women were enrolled from 2017 to 2022 and underwent two annual screening rounds of DBT and MBI. The women had an average age of 56.8 years and an average lifetime Tyrer-Cuzick risk of 12%. 

Adding MBI led to significant increases in breast cancers found for both screening years, including for invasive cancers. It also resulted in higher recall rates compared to DBT alone. 

Performance of DBT screening plus MBI in women with dense breasts

Measure

DBT

DBT plus MBI

P value

Cancer detection rate (year one)

5.0%

11.8%

<0.001

Invasive cancer detection rate (year one)

3.0%

7.7%

<0.001

Recall rate (year one)

8.6%

17.9%

N/A

Cancer detection rate (year two)

5.8%

9.3%

0.01

Invasive cancer detection rate (year two)

1.5%

3.9%

0.048

Recall rate (year two)

8.9%

13.8%

N/A

MBI alone detected cancers in 29 of the total women, 21 of whom had invasive cancers with a median size of 0.9 cm. Also, 26 of these women had node-negative cancers and six had advanced cancers.  

Finally, the team reported interval cancer rates of 0.7% (n = 2 out of 2,978) in year one and 0.8% (n = 2 out of 2,590) in year two. 

Hruska further explains her team’s findings and the study’s advantages.

Hruska said that future research will analyze the cost effectiveness of adding MBI to breast screening and improving exam times. She also told AuntMinnie.com that the team is gathering data that could help with standardization. 

“It’s an exciting time for breast screening,” Hruska said. “We’re at this point where there are many modalities that do a good job, and different practices have their niche technology that they like to use. We’re starting to understand the limitations of each modality and being more free to talk about them and communicate them to women.” 

The successful completion and reporting of the Density MATTERS trial may affect patient care, according to an accompanying editorial written by Amy Fowler, MD, PhD, from the University of Wisconsin-Madison. 

“Dissemination of the Density MATTERS trial results may help address current challenges for optimal integration of MBI into clinical practice and may lead to broader availability, use, and insurance coverage,” Fowler wrote. 

Read the full study here.

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