High-Resolution Breast Ultrasound May Reduce Biopsies

NEW ORLEANS—High-resolution ultrasound provides additional information about mammographically identified malignant calcifications and may find malignancies unseen on mammography, Beverly E. Hashimoto, MD, said at the annual meeting of the American Roentgen Ray Society.

 Dr. Hashimoto and her colleagues at Virginia Mason Medical Center, Seattle, prospectively studied 220 women with abnormal mammograms. The investigators performed high-resolution breast

ultrasound and interpreted the scans without access to any other clinical information. Masses were classified as malignant or benign, and microcalcification clusters were identified.

Of the 220 women, 86 had clustered calcifications on mammography without an associated mass, and 24 of these had histologically confirmed malignancy. High-resolution ultrasound detected calcifications in 20 (83%) of the 24 women with mammographically detected calcifications. But more importantly, high-resolution ultrasound revealed malignancy in 12 (60%) of these 20 women, and on biopsy, all of the lesions were found to be malignant.

High-resolution ultrasound was not as accurate at detecting nonmalignant calcifications: Of the 86 women with mammographic calcifications, ultrasound detected calcifications in only 58 (67%).

In an interview with Oncology News International, Dr. Hashimoto said, “Even though ultrasound is operator dependent, this technique is capable of detecting calcifications at a level much higher than previously possible. We were able to detect calcifications in two thirds of the women with mammographically identified calcifications, compared with a 5% detection rate with routine ultrasound.”

Dr. Hashimoto went on to say that, in the continuing effort to reduce the number of unnecessary biopsies, high-resolution ultrasound can play an especially important role, since the technique detected abnormal tissue in 60% of the women with no evidence of disease other than calcifications on mammography.

Dr. Hashimoto and her colleagues concluded that high-resolution ultrasound can detect calcifications in the majority of cases, but it is much better at identifying malignant calcifications than benign calcifications. Furthermore, when calcifications are detected mammograph-ically, high-resolution ultrasound may provide information useful for diagnostically risk-stratifying patients; that is, women with calcifications on both mammography and ultrasound have a much higher risk of having breast cancer.

“Even though our work must be considered preliminary,” Dr. Hashimoto said, “here at Virginia Mason we are now using this technique in cases where we normally wouldn’t have considered using ultrasound a few years ago.”