Pairing digital screening mammography with dose-efficient photon counting provides improved diagnostic performance of small invasive cancers and ductal carcinoma in situ (DCIS), according to a study published by Radiology on Feb. 4.

The shift to digital screening mammography has been accompanied by increased use of computed radiography (CR) and direct radiography (DR) technology. Of digital mammography systems, the photon-counting technique has exhibited the lowest mean glandular doses. Comprised of high-quantum efficiency parallel silicon strips and photon-counting electronics, the photon-counting technique decreases scatter radiation and noise.

Stefanie Weigel, MD, of University Hospital Muenster in Germany, and colleagues wrote of the photon-counting technique’s importance: “In population-based mammography, screening dose-reducing techniques are desirable, without compromising outcome parameters.” The researchers examined the screening performance parameters of a DR photon-counting system in comparison to statewide screening units that depend upon different digital technologies in their retrospective study.

Data from the mammography screening program in North Rhine-Westphalia, Germany, were gathered and analyzed. In order to compare the screening performance of a DR photon-counting scan system with statewide operating systems that employ different digital technologies, 13,312 women were examined using the photon-counting system and 993,822 women were screened with either CR or DR systems by themselves.

The study’s results revealed that the DR photon-counting scan system had a cancer detection rate of 0.76 percent, while the screening units had a cancer detection rate of 0.59 percent. The photon-counting technique had a 5.4 percent recall rate and the other screening units had a recall rate of 3.4 percent. The mean average glandular dose of the DR photon-counting scan system was significantly lower than the conventional DR systems.

Though the study may have been limited as the reporting of data derived from only one photon-counting unit, it benefited from its large size.

“The innovative photon-counting technique offers further research potential,” said Walter Heindel, MD, of University Hospital Muenster, in a press release. “One future research direction is the application of spectral imaging for quantification of breast glandular tissue, addressing the problem of breast density.”