 Digital Mammography in the 21st
Century
Reported by Michael Miller
September 4, 2001
On September 4, 2001, the National Cancer Institute
(NCI) and the American College of Radiology Imaging Network (ACRIN)
launched a multicenter study to determine if digital mammography meets or
exceeds capabilities, costs, benefits, and other factors, when compared to
standard film mammography for the detection of breast cancer. Digital
mammography is a technique for recording x-ray images in computer code
instead of on x-ray film, as with conventional mammography. The images are
displayed on a computer monitor (sometimes referred to as a workstation or viewbox) and can be enhanced before they are printed on film.
Etta Pisano, M.D., is the principal investigator for the
study and Professor of Radiology in the Breast Cancer Program,
Radiobiology & Imaging Program, at the University of North Carolina (UNC),
Chapel Hill. Behind the News talked with Dr. Pisano about various aspects
of the new study and other issues related to digital mammography.
Q: DIGITAL MAMMOGRAPHY PROMISES A LOWER RADIATION DOSE DUE TO IMPROVED
X-RAY ABSORPTION. WHAT WOULD THIS MEAN FOR A 40 YEAR OLD WOMAN OVER THE
COURSE OF HER LIFE WHEN COMPARING THE AMOUNT OF RADIATION FROM FILM VERSUS
DIGITAL MAMMOGRAPHY?
A: We don’t have very much information on that
yet. We think it’s going to reduce the dose, but we don’t know that
for sure. In the ACRIN trial, we are planning to match the dose -- not let
the digital dose be any higher than the film dose. We can certainly get
the same info out of a digital mammogram at a lower dose than film but we
might be able to get more information at a higher dose. One of the
limiting factors with film is that the higher the dose you apply, the
worse the image gets – there’s a natural limitation. With digital, you
can increase and increase the dose and you might get more information.
There’s not that same limiting factor that film has. Dose (for film) was
set arbitrarily many years ago and there’s no magic perfect dose. The
key thing is to find the cancer, so my feeling is that if we can find
cancer at a slightly higher dose within a range that’s acceptable, we
might end up doing digital mammography at a higher dose (than film), not
at a lower dose.
More on this story..
Cancer.gov,
The National Cancer Institute's Web site, provides accurate, up-to-date
information on many types of cancer, information on clinical trials,
resources for people dealing with cancer, and information for researchers
and health professionals.
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