ATLANTAWhen used to distinguish benign and malignant solid masses,
high-resolution ultrasound may reduce the number of breast biopsies by as much
as 28%, said Karen Hunt, MD, assistant professor of radiology, University of
Michigan, Ann Arbor. Dr. Hunt, who is also senior staff radiologist at Henry
Ford Hospital, presented the findings at the 102nd Annual Meeting of the
American Roentgen Ray Society’s (abstract 138).
The researchers evaluated 157 solid masses in 141 women. Of these lesions,
they identified 57 abnormal masses by mammography, 2 by MRI, and 98 by
palpation. Mean tumor size was 17 mm (range, 5 mm to 80 mm).
Eleven dedicated breast-imaging radiologists performed ultrasound
examinations and classified the masses prospectively as benign or suspicious
using a "gestalt" evaluation technique. According to Dr. Hunt, the
gestalt technique is difficult to define, but is based on the radiologists’
experience. The masses were also classified based on the previously published
Stavros criteria that define how a benign or malignant mass might appear on
ultrasound (see Figure).
Biopsies were then performed on 137 of the 157 masses, and from the
biopsies, 55 (40%) were classified as malignant and 82 (60%) as benign.
With the gestalt evaluation technique, 38 (46%) of the 82 histologically
benign masses were classified as benign, and all 55 (100%) of the cancers were
classified as suspicious. Therefore, this method would have prevented 38
biopsies, reducing the rate by 28%, Dr. Hunt said.
The Stavros criteria was slightly less effective in identifying benign
masses, classifying 24 (29%) of the 82 benign masses correctly, but, as with
the gestalt method, all 55 of the cancers were classified as suspicious.
Therefore, this method would have prevented 24 biopsies, reducing the rate by
18%. The advantage of the Stavros criteria, she said, is that specific
sonographic descriptors can be more easily replicated from institution to
"With larger numbers of masses evaluated, we expect that a few cancers
may appear benign on ultrasound," Dr. Hunt noted. "We expect this to
be quite rare, so imaging surveillance can be safely offered as an alternative
to biopsy. Ultrasound is a reliable test that should be part of the approach to
diagnosing these patients."