Innovative Mammography Technology Increases Detection Rate

A new photon-counting technique used with digital mammography screening has been shown to provide high diagnostic accuracy.

The study’s findings were published online February 2014 in the journal Radiology. While mammography screening has shifted to digital technology, a range of computed radiography (CR) and direct radiography (DR) systems have emerged. The photon-counting technique shows promise as a DR application that employs a unique detector to decrease scattered radiation and noise, enabling dose reduction and making it a promising tool for screening. “In population-based mammography screening, dose reducing techniques that don’t compromise outcome parameters are desirable,” said Walter Heindel, MD, from the department of clinical radiology at the University Hospital Muenster (Muenster, Germany).

For the study, Dr. Heindel and colleagues examined data for the study from the mammography-screening program in North Rhine-Westphalia, the most populated state in Germany. They compared the screening effectiveness of a DR photon-counting scan system with those of statewide operating screening units using different digital technologies. During the study period (2009–2010), 13,312 women were examined using the photon-counting system, and 993,822 women were screened with either CR or DR systems alone.

The DR photon-counting scan system had a cancer detection rate of 0.76% for subsequent screening, compared with 0.59% for the other screening units. The recall rate was 5.4% for the photon-counting technology and 3.4% for the other techniques. “The higher cancer detection resulting from the use of the DR photon-counting scan system is due to high detection of both small, invasive cancers and ductal carcinoma in situ,” Dr. Heindel said.

The photon-counting technique had nearly twice the detection rate of other techniques for ductal carcinoma in situ (DCIS), an early, noninvasive form of the disease. It had a higher DCIS detection rate than the statewide units and the conventional DR subgroup. Moreover, the mean average glandular radiation dose of the DR photon-counting scan system was substantially lower than the traditional DR systems with the individually used parameters of the automatic exposure control. The study’s large size distinguishes it from earlier studies that compared the DR photon-counting scan system’s performance with other approaches. “To our knowledge, the study is different from previous ones as we examined the performance of the DR photon-counting scan mammography on a larger database with consideration of multiple parameters of screening,” said study coauthor Stefanie Weigel, MD, from the University Hospital Muenster.

The photon-counting technique also offers lateral dose modulation during the image acquisition, which can help account for differences in breast density. Cancer frequently is more difficult to identify in women with dense breasts. “The innovative photon-counting technique offers further research potential,” Dr. Heindel said. “One future research direction is the application of spectral imaging for quantification of breast glandular tissue, addressing the problem of breast density.”

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University Hospital Muenster