The device has the potential to reduce the number of negative biopsies, thus saving women worry about breast lesions that turn out to be non-cancerous. It also has the potential to increase the identification of women who should be referred for early biopsy. It does not replace conventional methods of detecting or diagnosing breast cancer, such as mammography, clinical breast examination, ultrasound, or biopsy evaluation, but is intended to be used along with conventional methods. The probe is connected to a computer, which displays an image of the involved areas of the breast. The T-Scan images are based on differences in the electrical impedance between malignant tumor tissue and surrounding normal tissue.
Impedance is a measure of how any material affects the flow of electricity.
The device measures impedance by passing a small electrical signal through the body and displaying on a computer the result from sensors in the probe contacting the breast. The computer image contains bright spots where the impedance values are consistent with a possible malignancy. Approval of the device was based on the results of three clinical studies of safety and effectiveness performed by TransScan Medical and on the recommendation of an advisory panel of outside experts. In the first study, the radiologists evaluated the screening mammograms and T-Scan images of the entire breast from each of 504 women without knowing which patient's images they were reviewing or whether the women were suspected of having cancer. A second study of 657 patients, under conditions more closely resembling actual use, showed that targeting the T-Scan examination to suspicious areas of the breast can improve diagnostic accuracy to a greater degree than imaging the entire breast.