Computer-aided detection of mammograms improves breast cancer screening
18 October 2005
Aberdeen, UK and Bedford, Mass, USA. In screening mammograms for breast
cancer, the performance of radiologists using computer aided detection (CAD)
was superior to double reading, according to a recently published UK study.
The study titled "Single reading with computer-aided detection and double
reading of screening mammograms in the United Kingdom National Breast
Screening Program" was published in the October issue of the journal
This landmark study by researchers from two leading breast centres in the
United Kingdom measured radiologists' performance with the use of CAD. The
study also showed a 15% increase in cancer detection rates when CAD was
used. The CAD system (ImageChecker 1000 version 5.0) used in this study was
supplied by R2 Technology, a subsidiary of diagnostic imaging supplier
Hologic Inc. (NASDAQ:HOLX).
The CAD program scans a mammogram for suspicious features or
abnormalities that could represent breast cancer. When the computer finds
anything unusual it indicates the abnormality on a screen for the
radiologist to check. The CAD system used in this study features proprietary
R2 EmphaSize(TM) software, which provides variable size marks that correlate
to lesion significance. A larger mark indicates that the CAD algorithm
detects more mammographic features that are indicative of cancer. The marks
prompt the radiologist to double check suspicious areas, particularly
focusing on features with larger CAD marks.
The study included a sample of more than 10,000 mammograms obtained from
women aged 50 years or older who underwent routine screening. Mammograms
that were double read initially were randomly allocated to be re-read by
eight different radiologists using a single read and CAD. Cancer detection
rates and recall rates from double reading and single reading with CAD were
then compared. The researchers found that single reading with R2 CAD
detected 6.5% more cancers — a 15% increase in the cancer detection rate —
than that achieved with double reading (P=0.02)
Professor Fiona Gilbert, of Aberdeen University, who led the study, said:
"The results of this trial are very encouraging. The mammograms studied were
from a sample taken in 1996 so that all cancers that developed subsequently
in this group of women could be included. The study was retrospective so the
radiologists taking part in the trial knew no action would be taken as a
result of their decisions."
"We have now embarked on a new study to confirm that the CAD result is
still as good when used in real day to day decision making about breast
cancer diagnosis," Professor Gilbert added.
Dr. Sue Astley of Manchester University who also worked on the study
said: "This new prospective trial will involve 30,000 women in three major
screening centres, most of whom will have single reading with CAD in
addition to their routine double reading. This is an opportunity for women
in the UK to have their mammograms read using the latest CAD technology
which is already available in America and other countries."