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T99-18                     Sharon Snider:       301-827-6242   
April 19, 1999               
                           Consumer Inquiries:  888-INFO-FDA

FDA APPROVES NEW BREAST IMAGING DEVICE

The Food and Drug Administration has approved a new imaging device that will help radiologists determine whether a woman should be evaluated further when the results of her mammograms are ambiguous. It is not intended for use in patients with clear mammographic or non-mammographic indications for biopsy.

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.

The T-Scan 2000, manufactured by TransScan Medical, Inc., of Ramsey, N.J., is intended for use as a follow-up step to mammography for patients whose mammograms are ambiguous.

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 T-Scan uses a hand-held scan probe placed on the breast to evaluate certain suspicious areas detected on the mammogram. 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. The results showed that in women with ambiguous mammograms, the additional use of T-Scan images improved diagnostic accuracy, i.e., detection of potentially cancerous lesions and discrimination from non- 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.

In a third study, of 36 women with mammograms with ambiguous results, the T-Scan was targeted at the equivocal mammographic lesion and reviewed simultaneously with the mammogram. This third study, which reflects the approved intended use for the T-Scan, showed even greater improvement in diagnostic accuracy.

Together the three studies showed that, when used along with screening mammography, T-Scan gives doctors a useful tool to enhance care of women whose mammogram results are ambiguous.

As a condition of approval, TransScan Medical is being required to conduct a post-market study on the effects of hormonal changes during the menstrual cycle on the deviceís ability to detect and distinguish among breast abnormalities.

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