This prospective study is to determine whether predictive model for contrast-enhanced ultrasound (CEUS) of the breast can improve the precision of BI-RADS.
A total of 1060 breast lesions classified as BI-RADS 4 or 5 on ultrasound were evaluated. CEUS was performed before core needle biopsy or surgical resection and a revised BI-RADS classification was assigned based on 6 predictive models for CEUS of malignant and benign breast lesions as follows: malignant predictive models : (1) hyper-enhancement with enlarged size; (2) hyper-enhancement with perfusion defect; (3) hyper- or iso-enhancement, present penetrating vessels or crab claw-like pattern. Benign predictive models: (4) rapid wash-in with hyper-enhancement, clear margin after enhancement without enlarged size; (5) synchronous or slow wash-in with iso-enhancement, and cannot distinguish margin and shape after enhancement; and (6) synchronous or slow wash-in with hypo-enhancement, with equal or smaller size after enhancement. To evaluate the diagnostic performance of CEUS-based BI-RADS assignment with pathological examination as reference criteria.
The CEUS-based BI-RADS evaluation classified 287/1060 (27.08%) lesions into category 3, 195 (18.40%), 124 (11.7%) and 144 (13.58%) lesions into categories 4A, 4B and 4C, respectively, and 310 (29.24%) into category 5, compared with 423/1060(39.91%), 348(32.83%), 150(14.15%) and 139(13.11%) in BI-RADS 4A, 4B, 4C. and 5 based on conventional ultrasound and mammography. Selecting CEUS- based BI-RADS category 3 as an appropriate cut-off gave accuracy, sensitivity, specificity, positive and negative predictive values of 69.25%, 98.06%, 49.47%, 58.99% and 96.86%, respectively for the diagnosis of malignant disease. The cancer-to-biopsy yield was 60.16% with CEUS-based BI-RADS 3 selected as the biopsy threshold compared with 43.86% otherwise, while the biopsy rate was only 72.92% compared with 100% otherwise (Figure 2). Overall, only 1.94% of invasive cancers were misdiagnosed as BI-RADS 3 we use nowadays.
This study suggests that evaluation of BI-RADS 4 or 5 breast lesions with CEUS result in reduced biopsy rates and increased cancer-to-biopsy yields.
Clinical trial identification
2016-14-1 release date: 9/9/2016.
Legal entity responsible for the study
Ultrasound Department of Sichuan Provincial People's Hospital.
Has not received any funding.
All authors have declared no conflicts of interest.