There’s a new study out on mammography with important implications for breast cancer screening. The main result is that when radiologists review more mammograms per year, the rate of false positives declines.
The stated purpose of the research*, published in the journal Radiology, was to see how radiologists’ interpretive volume — essentially the number of mammograms read per year — affects their performance in breast cancer screening. The investigators collected data from six registries participating in the NCI’s Breast Cancer Surveillance Consortium, involving 120 radiologists who interpreted 783,965 screening mammograms from 2002 to 2006. So it was a big study, at least in terms of the number of images and outcomes assessed.
First — and before reaching any conclusions — the variance among seasoned radiologists’ everyday experience reading mammograms is striking. From the paper:
…We studied 120 radiologists with a median age of 54 years (range, 37–74 years); most worked full time (75%), had 20 or more years of experience (53%), and had no fellowship training in breast imaging (92%). Time spent in breast imaging varied, with 26% of radiologists working less than 20% and 33% working 80%–100% of their time in breast imaging. Most (61%) interpreted 1000–2999 mammograms annually, with 9% interpreting 5000 or more mammograms.
So they’re looking at a diverse bunch of radiologists reading mammograms, as young as 37 and as old as 74, most with no extra training in the subspecialty. The fraction of work effort spent on breast imaging –presumably mammography, sonos and MRIs — ranged from a quarter of the group (26 percent) who spend less than a fifth of their time on it and a third (33 percent) who spend almost all of their time on breast imaging studies. Read more »
*This blog post was originally published at Medical Lessons*