Digital Tomosynthesis Reduces Mammography Recall Rate

Digital Tomosynthesis Reduces Mammography Recall Rate

A recent study evaluated the potential role of digital breast tomosynthesis in diagnostic mammography, and compared digital breast tomosynthesis versus film-screen mammography in a diagnostic mammography setting.

The results, published in AJR, indicate that digital tomosynthesis reduces the mammography recall rate.

The Study
The study included 98 women who had abnormal findings on digital screening mammography.

Methodology
Subsequently, digital tomosynthesis and film-screen diagnostic mammography were performed on these women.

The results of the two modalities and the results of ultrasound, MRI, and biopsy were reviewed.

Tomosynthesis acquisition included 11 low-dose X-ray exposures with the total radiation dose per acquisition being 400 mrem (4mSv). These images were reconstructed into 1-mm-thick slices for review by radiologists.

Results
In most cases, the image quality of tomosynthesis was rated as equal or superior to that of film-screen mammography by the radiologists in the study.

The use of tomosynthesis generated an additional eight recalls and discarded a significant number of original recalls such that the recall rate was reduced by 40%.

The reduction in the recall rate was mostly due to identifying initial findings (such as asymmetry, focal asymmetry, and questionable architectural distortion) as summation of tissue on tomosynthesis.
Tomosynthesis and film-screen mammography detected the same number of cancers in the study.

Conclusions
Digital tomosynthesis may offer superior image quality and may have a potential role in reducing the recall rate of screening mammography.

Reviewer’s Comments
The clinical applications of full-field digital mammography have allowed radiologists to investigate digital tomosynthesis as an alternative approach to traditional mammography.

In most breast imaging practices, approximately 10% of screening mammography patients are recalled for an additional diagnostic mammographic workup and/or ultrasound.

Often, additional mammographic views performed during the diagnostic workup reveal that original abnormal findings simply represent summation of breast tissue.

Although the study has several limitations, its results suggest that digital breast tomosynthesis may have a potential role in reducing the recall rate of screening mammography and, therefore, reducing the false-positive rate of mammography.

A large prospective double-blind study using both digital tomosynthesis and full-field digital mammography with a longer follow-up period is needed before digital tomosynthesis can be incorporated into clinical breast imaging practices.

Author: Bokran Won, MD
Reference:
Poplack, Steven P., Tosteson, Tor D., Kogel, Christine A. and Nagy, Helene M. Digital Breast Tomosynthesis: Initial Experience in 98 Women with Abnormal Digital Screening Mammography. AJR 2007; 189:616-623