DR more effective than CR in detecting breast cancer

A new study in the journal Radiology shows that digital direct radiography (DR) is significantly more effective than computed radiography (CR) at detecting breast cancer. The findings are the first to show a difference between the two types of digital imaging when compared with screen film mammography. The results  suggest that women should be informed of the potential for lower cancer detection with CR. While numerous studies have been published comparing digital mammography with screen film mammography, less is known about the comparative effectiveness of DR and CR, according to Dr Anna M. Chiarelli, senior scientist in Prevention and Cancer Control at Cancer Care Ontario in Toronto, Canada. “Digital mammography was implemented progressively in Ontario starting in 2006, and since that time there’s been no evidence in the literature to suggest that CR did not perform as well as DR,” she said.

For the new study, Dr. Chiarelli and colleagues drew upon information from the Ontario Breast Screening Program (OBSP), initiated in 1990 to deliver breast screening to women between the ages of 50 and 74. A total of 403,688 women were screened by screen film mammography, while 220,520 had DR and 64,210 underwent CR. The women were followed for 12 months after screening. DR detected 4.9 cancers per 1,000 mammograms, a figure almost identical to screen film mammography’s rate of 4.8 cancers per 1,000 mammograms. However, CR’s detection rate of 3.4 cancers per 1,000 mammograms was significantly lower. In fact, CR was 21 percent less effective than DR. This could result in about 10 fewer cancers being detected per 10,000 women screened. “There may be several technical reasons reported by others for the lower effectiveness of CR, including loss of spatial resolution, or sharpness, and increased image noise, or granularity,” Dr Chiarelli said. The new results carry more weight than those of previous studies because of the larger number of women screened and the reliance on concurrent cohorts.

http://tinyurl.com/Cancer-Care-Ontario