Radiology Roundup: Mammography Trends and Breakthroughs

2017-07-06
 

Radiology is a rapidly-advancing, ever-evolving field, and mammography is no exception to the rule. In the past decade, researchers and practitioners have added to the breadth and depth of mammography study at a steady pace, from new technologies like digital breast tomosynthesis to new research on breast density.

This roundup explores the current state of mammography, the latest research, and breakthroughs that are waiting just over the horizon.

1. Mammography Trends Show Improved Cancer Detection, More Biopsies

The move to digital mammography — as opposed to film — has had a significant impact on breast cancer detection and treatment. According to a new study from the Breast Cancer Surveillance Consortium (BCSC), cancer detection rates have increased since the switch to digital in 2005, from 25.3 per 1,000 to 34.7 per 1,000.

The news is not all positive, however. The increase in detection has been accompanied by a rise in the abnormal interpretation rate, and a drop in positive predictive value. According to the BCSC, these findings suggest that digital mammography is better at identifying abnormalities than discriminating between benign and malignant findings.

2. Does Reader Performance with Digital Breast Tomosynthesis (DBT) Vary according to Experience with Two-dimensional Mammography?

DBT has proven effective in increasing the efficiency of breast cancer screening. Previous research found a 27% increase in overall detection rate, coupled with a 15% decrease in false-positive recall rate with DBT supplementing two-dimensional mammography.

New research published in the RSNA Radiology Journal studied whether these improvements remain consistent across differing levels of breast cancer screening experience. The study included radiologists, advanced practitioner radiographers, and breast clinicians across the spectrum of experience. Each underwent a one-day orientation on DBT.

The study found that while experience played a substantial role in interpreting scans, DBT did increase effectiveness across experience levels.

 3. National Performance Benchmarks for Modern Screening Digital Mammography

In the latest volume of the RSNA Radiology Journal, the BCSC updated their benchmarks for mammography performance. The study examined how breast clinicians are currently performing in a wide selection of measures, including cancer detection rate, false-negative rate, positive predictive value, and abnormal interpretation rate.

The study shows that the majority of radiologists in the BCSC surpass recommended levels for cancer detection. Abnormal interpretation rate, however, continues to be above the benchmark rate for nearly half of the radiologists evaluated.

4. Breast Cancers Found by Mammography Do Not Regress If Left Untreated

A new study published in the Journal of the American College of Radiology challenges the conventional wisdom that some cancers found through mammography will spontaneously be re-absorbed if left untreated. Some have used this claim to support delaying the onset of screening or increasing the time between screenings.

The study examined over 30,000 cases of invasive breast cancer and ductal carcinoma in situ. Among these cases were nearly 500 that were diagnosed but not treated. None of these were shown to have spontaneously vanished or even regressed in subsequent mammograms. These findings suggest that medical science has no reliable way of determining which cancers will regress or advance.

5. Photon-Counting Breast CT Shows Promise

A new prototype CT breast scanner has the potential for breast cancer screening without the uncomfortable necessity of breast compression. The prototype, built by a study team at Duke University Medical Center, was shown to be effective at identifying anomalies in non-biological models and in a cadaver breast.

The addition of photon-counting detectors to breast CT appears to hold the promise of low-dose image acquisition without compression. The team at Duke University Medical Center also believe the underlying technology could support spectroscopic acquisition, which could be useful for differentiating between malignant and benign tissue.

Breast cancer screening has advanced significantly just in the past decade, as DBT increases scan sensitivity and best practices continue to evolve. The challenge is to use new technologies to increase cancer detection rates without also increasing recalls and false-positives.

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