Elastography Imaging During Breast Ultrasound Reduces Unnecessary Biopsy rate
By Fran Lowry
Medscape Medical News
December 1, 2009 (Chicago, Illinois) — Elastography imaging performed during breast ultrasound is extremely helpful in evaluating breast lesions and selecting patients who need a biopsy, according to new research presented here at the Radiological Society of North America 95th Scientific Assembly and Annual Meeting.
"Elastography is a technique that you can use as you are scanning the patient; there is no radiation involved, it takes just a minute or 2 to perform, and it gives you more information about what it is you are looking at," said Stamatia Destounis, MD, from the University of Rochester School of Medicine in New York.
The technique involves pressing on the breast with an ultrasound probe to measure the firmness or resistance of the underlying tissue.
"The hypothesis is that firm areas, like cancers, tend to be very dense, very firm. They are not very mobile, and the tissue does not move much and will look different on elastography than soft areas in the breast that are very compressible," Dr. Destounis explained to Medscape Radiology. "A cancer will be stiffer than the surrounding tissue."
She and her colleagues performed 198 elastographies on 193 patients, who then went on to have their lesions biopsied. They found that elastography correctly determined that a lesion was cancerous in 58 of 59 cases, for a concordance rate of 98%.
Elastography also differentiated benign from malignant lesions in 54 of 69 cases, for a concordance rate of 78%.
Cancerous lesions appear larger on elastography, and benign lesions appear smaller, Dr. Destounis told Medscape Radiology.
"The lesion is measured on 2D ultrasound and then measured with elastography, and the images appear side by side, with 2D on the left and the elastography image on the right," she explained. "If it is a cancer, it will measure bigger on the elastogram because elastography measures stiff tissue — not just the tissue that is seen on ultrasound, but the stiffness around the mass — and cancers tend to be stiff."
Benign lesions appear smaller, she said. "It's not always as clear where your measurement is because some masses that are benign, like fibrocystic tissue, can blend into the rest of the breast tissue on the elastogram."
She stressed that elastography is not going to eliminate the need for biopsy in all cases.
"Most of the time you are going to end up biopsying things just to be on the safe side. But elastography gives you more information. In benign cases, it will save patients from undergoing unnecessary biopsies."
Commenting on this study for Medscape Radiology, Richard G. Barr, MD, PhD, from Northeastern Ohio Universities College of Medicine in Rootstown and Radiology Consultants, Inc. in Youngstown, said he has used elastography as a standard part of a breast ultrasound examination since the technique was approved by the US Food and Drug Administration in 2006.
"We cancel approximately 50% of breast biopsies sent to us by adding elastography to the work-up. We believe that it is an important tool and should be included as part of a standard breast ultrasound."
Like Dr. Destounis, Dr. Barr said that patients with suspicious lesions will still need a biopsy for tissue diagnosis.
He also predicted that continued refinement of elastography will allow for it to be used as a screening tool in the near future.
Eliminating unnecessary biopsies will be a good thing for women, both physicians told Medscape Radiology.
"Even when a woman has a biopsy that turns out to be negative, she still can still worry and continue to have a lot of anxiety as a result. There is a huge emotional component to biopsy," Dr. Barr said. "If we are able to tell a woman up front that we don't need to do a biopsy, it really helps to alleviate their anxiety."
Dr. Destounis and Dr. Barr have disclosed no relevant financial relationships.
Radiological Society of North America (RSNA) 95th Scientific Assembly and Annual Meeting: Abstract LL-BR4059. Presented November?29, 2009.
