Ultrasonography can be used as a supplement to routine screening of young, pregnant and lactating women, women with dense breast tissue on mammography, and those at high risk, targeting an area of concern in the breast (Figure 2). It may detect an additional 3-4 cancers per 1000 women in high-risk groups. More than 90% of cancers seen only on ultrasonography are in dense breasts, of which 94% are invasive and 70% are less than 1 cm in size and are thus clinically impalpable.
A combination of negative diagnostic mammogram and negative ultrasonography has a sufficiently high negative predictive value (NPV) that biopsy of a low-suspicion palpable mass is not indicated. On the other hand, PPV of biopsy for lesions seen only on ultrasonography is low, averaging 11%.
Ultrasonography is particularly useful to localize and allow biopsy of lesions seen on MRI but not on mammogram. Its role in preoperative staging of the axilla is also being studied. Malignant lymph nodes are identified by loss of fatty hilum and cortical nodularity.[37,38]
The utility of screening ultrasonography is still under investigation in a large randomized trial, the American College of Radiologists Imaging Network (ACRIN) study. While breast ultrasonography is painless and requires no radiation, it relies heavily on the operator's experience. To reduce the inconsistencies arising with hand-held transducers, some companies are developing an automated multidetector sweep-scanning device that will permit precise localization and correlation in two planes within the breast, and may also allow reconstitution of images in a coronal plane.[34,36]
Future Oncol. 2008;4(4):501-503. © 2008 Future Medicine Ltd.
Cite this: New Diagnostic Techniques for Breast Cancer Detection - Medscape - Aug 01, 2008.