Based on a Belgian study published online in European Radiology, radiologists interpreting breast screening studies had similar performances irrespective of whether the images were obtained using computed radiography (CR) or digital radiography (DR) mammography systems. Yet, DR still registered at a lower dose than CR.

Lately, researchers have voiced concern about the efficiency of CR-related mammography as opposed to DR. In another study conducted by Canadian researchers and published in Radiology, it was noted that CR was 21% less effective than DR in cancer recognition.

However, lead author of the Belgian study, Dr. Hilde Bosmans, of University Hospitals Leuven, and her team point out that their study’s findings suggest that the concern is foundationless.

“Our screening indicators are reassuring for the use of CR and DR. Screening performance parameters for CR and DR technology are not significantly different,” noted the study.

Data which assesses CR procedures in a screening set-up are quite sparse, irrespective of the fact that most of these systems are broadly used across Europe. In an effort to set things right, the team weighed technical and clinical screening performance restrictions between the two systems, including data from 73,008 women screened with CR and 116,945 women screened with DR between 2008 and 2010; with both groups being screened twice.

Clinical determinants that were taken into account by the team were recall rate, cancer detection rate, percentage of ductal carcinoma in situ identified, percentage of cancers with T-scores smaller than 1 cm, and positive predictive value.

The study itself yielded interesting results. From the study it was shown that:

1.  Recall rates for CR and DR in the first round of screening were 5.48% compared with 5.61%; subsequent screening rounds had recall rates of 2.52% and 2.65%.
2.  Cancer detection rates were 0.52% for CR and 0.53% for DR.
3.  Rates of ductal carcinoma in situ (DCIS) were 0.08% for CR and 0.11% for DR.
4.  Rates of cancers with T-scores smaller than 1 cm were 0.11% for both technologies.
5.  The positive predictive value of CR was 18.45% compared with DR's 18.64%.

Yet none of these parameters presented any significant differences between CR and DR systems.

However, there was one slight difference in the two technologies, that being, both of them required different mean glandular dose (MGD). The study determined this by calculating the MGD level of standard procedure and noted that CR's MGD was 2.16 mGy, while DR’s was 1.35 mGy, a 60% difference. And while these calculations still fall under the guidelines issued in 2006 by the European Council, Bosmans and her team believe CR’s higher MGD should be factored in.

"The higher doses used with CR technology versus DR for a screening examination at the age of 50 years could lead to an extra 1.6 radiation-induced cancers per 100,000 women screened. However, the expected benefit of reduction in premature mortality afforded by routine mammographic screening in terms of either lives saved or years of life saved greatly exceeds this risk,” they commented.