Computer-Aided
Detection Improves Early Breast Cancer Diagnosis
 CAD,
computer-aided detection, is computer software that uses a normal
mammogram film or a digital mammogram. The program searches for
abnormal areas of density, mass, or calcification that may indicate
the presence of cancer. The CAD system highlights these areas on
the images, letting the radiologist know that there is a need for
further analysis.
CAD
can help radiologists detect breast cancer earlier and pinpoint
micro-calcifications that may be early cancer. In one study, CAD
correctly identified 71% of cancers missed by two readers. Another
study of 18,586 screening mammograms confirmed that by using CAD
radiologists are able to identify more cancers earlier.
"Our
study indicates that by using a CAD system there is a potential
to increase the pick-up rates of breast cancer earlier," said
Stamatia Destounis, M.D., from The Elizabeth Wende Breast Clinic
in Rochester, N.Y. and lead author of the study published in the
August 2004 issue of the journal Radiology.
For
the study, Dr. Destounis and colleagues reviewed the cases of 519
patients with proven breast cancer. Prior screening mammograms were
available for 318 patients and yielded a total of 98 "false-negatives,"
or missed cancers. Three out of five reviewers identified 52 actionable
cancers that, in retrospect, appeared as visible abnormalities on
prior screening mammograms, but had been missed by two breast imaging
specialists doing a non-blinded, double-read.
The
researchers, retrospectively, then used CAD to scan and analyze
the "false-negative" mammograms. CAD correctly marked
37 (or 71 percent) of the 52 visible cancers missed during the double-read.
"Finding
cancer earlier, we believe, is the best chance for longer cancer-free
survival, resulting in less surgery, less chemotherapy and less
stress on the patient and her family," Dr. Destounis said.
Computer-aided
detection finds breast cancers earlier in both screening and diagnostic
patients according to another study done by a private practice radiologist
in Santa Barbara, CA. which appeared in the July 2006 issue of the
American Journal of Roentgenology
“Early
detection is essential in preventing breast cancer deaths, so as
a mammography specialist, I’m always looking for tools to improve
cancer detection,” said Judy Dean, MD, and lead author of the
study.
“This
study began as acceptance testing for the CAD system I purchased
for my mammography practice in 2002. I scanned 50 known cancer cases
and 50 normal mammograms to see how the software would perform on
films from my own practice and was astounded to find that it marked
90% of the cancers. I was really surprised that a computer program
could achieve that level of sensitivity, so I decided to see what
effect it would have when put into day-to-day use in my practice,”
said Dr. Dean.
“We
collected data until more than a hundred cancers had been found,
and then analyzed the results to compare what types of cancers were
found with and without CAD assistance,” said Dr. Dean. “We
used the CAD system for every mammogram performed during the study,
not just screening patients, and even in patients with prior surgery,
breast implants, or other findings, CAD was helpful in finding more
cancers.”
During
a 28 month period, 9,520 film-screen mammograms were interpreted.
According to the study screening-detected cancers increased 13.3%
with CAD assistance and 9.5% in diagnostic exams. The greatest impact
was on ductal carcinoma in situ (DCIS), the most common type of
non-invasive breast cancer in women, for which CAD increased cancer
detection by 14.2%.
“Cancer
detections were higher in both screening studies and symptomatic
patients. This means that CAD should be used for all mammograms,
not just routine screening examinations,” said Dr. Dean. “According
to the ACR, there are currently 8,881 accredited mammography facilities
in the United States but only 4,000 are using CAD.”
“The
principal barrier with CAD is the cost, and a proposed 50% reduction
in Medicare reimbursement will make the technology out of reach
for most small and medium sized facilities,” said Dr. Dean.
“These may be the very places that need CAD the most, as prior
studies have shown that CAD has the most impact for non-specialist
radiologists,” she said.
• Computers Significantly Increase Breast Cancer Detection Rate
• Computer Helps Detect Breast Cancer Earlier
• New Technologies to Help Improve Mammography
• Improving Methods for Breast Cancer Detection and Diagnosis
• CAD software improves characterization of suspicious masses on breast ultrasound
• Computers Increase Detection Rate Of Breast Cancer
August
1, 2006
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