3D mammography may improve cancer detection rates

New York Times : Unlike the flat, cross-sectional image of traditional mammograms, tomosynthesis uses a moving x-ray camera to create a 3D image. Approved for use in the US in 2011, the new system is used in some 1100 mammography units. Early results for the effectiveness of the imaging are promising but not definitive. When the researchers compared 281 187 traditional mammography screenings with 173 663 combined traditional and tomosynthesis screenings, they found that the combined system detected cancer in 5.4 of every 1000 scans compared with 4.2 detected by traditional mammography. The combined screening also improved the detection of invasive cancers: 4.1 per 1000 scans compared with just 2.9 found with digital mammography alone. Although the combined scans did not improve the detection of the less threatening ductal carcinoma in situ cancers, many doctors think that nothing is gained by treating them anyway. The combined screenings also reduced the number of follow-up visits that result from false positives. Other studies have indicated that the additional x rays required to eliminate false positives may have an overall negative effect on long-term health.