Ha Young Kim, Presenter: Nothing to Disclose

Nariya Cho MD, Abstract Co-Author: Nothing to Disclose

Woo Kyung Moon MD, Abstract Co-Author: Nothing to Disclose

Se Yeong Chung MD, Abstract Co-Author: Nothing to Disclose

To evaluate the negative predictive value of elastography for suspicious abnormal lesions detected by supplemental screening US and to find out whether elastography is helpful in reducing the number of benign biopsies, using histological analysis as a reference standard.

Between May 2006 and March 2008, 1098 consecutive women who were scheduled to undergo US-guided core biopsy due to 1122 breast lesions detected by supplemental screening US were examined with a commercialized US-elastography. All patients with US detected lesions had negative non-fatty mammogram. Lesions with category 3 (n= 224), atypical ductal hyperplasia (n=20), and larger than 3.0cm (n=13) were excluded. A total of 864 lesions (mean size 1.0cm, range 0.3 - 3.0cm; BI-RADS category 4a /4b /4c /5; 757 / 66 / 28 /13 lesions) in 842 women (mean age 46, range 30-68) formed our study group. Elastographic images were prospectively classified as positive (abnormal strain) and negative (normal strain) based on the degree of strain induced by light compression. We investigated whether there was a subset of benign lesions that were categorized as suspicious abnormality by conventional US, but as negative by elastography.

Of the 864 suspicious abnormal lesions, 79 (9.1%) lesions were confirmed as cancers (77 positive, 2 negative at elastography). Of the 224 lesions with negative elastography (216 category 4a, 8 category 4b lesions), 2 lesions (0.9%) proved to be cancers (0.7 and 1.6cm, low grade DCIS). Of the 640 lesions with positive elastography, 77 lesions (12.0%) proved to be cancers (59 invasive ductal carcinomas, 18 DCIS) (p< 0.001). The rate of malignancy for BI-RADS category 4a / 4b / 4c / 5 lesions were 2.6% / 36.4% / 58.6% / 100%, respectively. For the BI-RADS category 4a lesions, 28.5% (216 of 757) had a normal strain and 99.1% (214 of 216) of lesions with normal strain found out to be benign.

The negative predictive value of elastography was 99.1% in 862 suspicious abnormal lesions detected by supplemental breast US. When a lesion categorized as BI-RADS category 4a has a normal strain on elastography, a biopsy may be averted.

Addition of US-elastography to supplemental screening breast US has potential to reduce benign biopsy for BIRADS category 4a lesions that are detected by supplemental screening US.

Kim, H, Cho, N, Moon, W, Chung, S, Ultrasound (US): Elastography of Suspicious Abnormal Breast Lesions Detected by Supplemental Screening US.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6020400.html