HOPKINTON, MassA new breast mapping system under development by
Assurance Medical is designed to provide physicians with an
objective, quantitative approach to the clinical breast examination.
In essence, it allows the physician to visualize what is felt on the
The physician uses a hand-held device, the Electronic Tactile Sensor
Array (see figure), comprised of more than 400 miniature pressure
sensors, to electronically palpate the breast. On the computer, the
physician is then able to view a focus area via an image that
reflects the mechanical properties of the underlying breast tissue.
This image and associated parameters can be recorded and retrieved
for serial comparison to determine changes over time in the area of
focus (see illustration ).
Unique Pressure Signatures
The pressure sensors can show such palpable properties of tissue as
hardness, stiffness, size, and discreteness. Initial studies
indicate that different tissue structures within the breast (eg,
cysts, fibro-adenomas, and cancers) exhibit unique pressure
signatures, and the device may be effective at differentiating the
pressure signatures of abnormal breast lesions from those of normal
breast tissue, Joel B. Weinstein, vice-president of sales and
marketing for Assurance Medical, said in an interview.
The intent of the productthe BreastView Visual Mapping
Systemis to provide an extension of the physical exam and
specifically to make it more objective and better documented,
Mr. Weinstein said. The investigational device is not designed to
replace existing screening modalities, he said, but rather to be used
as an adjunct.
It allows the physician to objectively follow women with
abnormal findings, such as fibrocystic tissue, that may not warrant
starting a routine of diagnostic mammography and potentially
biopsy, he noted.
Assurance Medical demonstrated the new device to physicians at their
exhibit at the 21st Annual San Antonio Breast Cancer Symposium.
Edward Dalton, MD, of Northern New England Surgical Associates,
Manchester, New Hampshire, who participated in the initial trials of
the device, said that the ideal candidate for breast mapping is
the high-risk woman with a dense mammogram and a focally difficult
breast exam. These women often appear repeatedly, referred by an
insecure primary care physician.
The BreastView device, Dr. Dalton said, has been an excellent
way to improve the documentation and record keeping surrounding a
focally difficult exam. The software can also store ultrasound
images, x-ray reports, and communications and recommendations to a
In early studies in which the results were interpreted via a visual
display of the pressure signals, the system showed an overall
sensitivity of 92% (detecting 108 of 118 palpable and nonpalpable
lesions) vs 86% for the physicians exams (102 of 118 lesions).
The device correctly detected all eight palpable cancers found in the
study population and two of three nonpalpable cancers.
A phase III feasibility study employed advanced computer algorithms
to identify the nature of specific structures by quantifying the
tissues palpable characteristics. This program causes the
sensor to emit an audible tone when a suspicious feature is found. In
this study, the device detected 70 of the 75 lesions that were 1 cm
or larger in diameter (93% sensitivity). Four cancerous lesions were
found in the study, and the BreastView system accurately detected
both of the two lesions that were within the devices intended
range of 1 to 2.5 cm in size, Mr. Weinstein said.
The company has now performed a clinical study on 100 women to
confirm the accuracy and reproducibility of the device. The
results showed that the device is very accurate in terms of sizing
lesions when compared with the actual excised lesions, Mr.
The results showed a high level of reproducibilitywithin a
couple of millimetersfor the mapping system. Furthermore, he
said, the BreastView system was able to identify 35 structures
that were not visualized on mammography, including five cancers.
The company is now moving forward with a formal FDA clinical study of
the device, which is expected to begin in March 1999, Mr. Weinstein
said. He anticipates that, when available, the complete
systemsensor, software, computer, and printerwill cost