Electrical impedance scanning of the breast involves the transmission of continuous electricity into the body using either an electrical patch attached to the arm or a hand held cylinder. The electrical current travels through the breast where it is then measured at skin level by a probe placed on the breast.

Investigational/Not Medically Necessary:

Electrical impedance scanning of the breast is considered investigational/not medically necessary for all indications.
 

There are a few case series reported in the literature on electrical impedance scanning of the breast. Some studies focused on the technical capability of electrical impedance scanning. All of those studies that reported on the diagnostic performance of electrical impedance scanning reported an inferior performance to that reported in the FDA Summary of Safety and Effectiveness. The level of evidence supporting the conclusion that the use of electrical impedance scanning of the breast is investigational rises to include randomized controlled trials.

The majority of patients studied with electrical impedance of the breast were involved in the study presented to the FDA during the approval process for the T-Scan 200 device. This initial comparative study was performed in a blinded fashion but involved no randomization. Using biopsy results as the gold standard, the sensitivity of the combined mammogram and T-Scan compared to mammogram alone increased from 60% to 82%, while the specificity increased from 41% to 57%. Both of these are statistically significant increases. However, it is unclear from this study if these diagnostic parameters would enable patients with equivocal mammographic abnormalities to forego biopsy. Recalculating the data reveals that the key parameter of the negative predictive value of the combined test is 93%. Therefore, if the decision to forego biopsy was based on a negative result of the combined mammogram and T-Scan, 7% of those with malignant lesions would miss or delay a diagnosis of breast cancer.

Additionally, this study included some BI-RADS three or four lesions, but it is not specified whether the biopsies were performed in these subjects as part of the study protocol or based on clinical suspicion and/or imaging results. The analysis of diagnostic performance included only those patients who were scheduled for biopsy, which introduces the potential for verification bias. It is uncertain whether these selected cases would be similar to unselected consecutive cases of BI RADS three or four lesions that would not be referred for biopsy in clinical practice. The positive predictive value of adjunctive use of the T Scan was reported to be 30% among biopsied subjects with BI-RADS 3 or 4 lesions and an 18% prevalence of malignancy. However, the limitations and potential bias in this analysis prohibits conclusions regarding the effectiveness of using the T-Scan in positively selecting patients for biopsy.

Ideally one would like to design a trial in which all patients with equivocal lesions, which would otherwise be referred for follow-up imaging, undergo both T-Scan and biopsy or some other appropriate reference standard such as prolonged clinical follow-up. In this setting, the diagnostic performance and predictive value of T-Scan could be evaluated in the actual intended use.

To address this issue, the “Intended Use” study presented to the FDA consisted of a small case series study of 74 consecutive biopsy cases in which the T-Scan was approved for clinical use in its full intended mode. Of these patients, less than half had biopsy results. Mammograms and T-Scans were available where the mammographic results were equivocal. While this study did provide positive findings, the small number of cases, along with the potential bias associated with the fact that analysis was restricted to less than half of subjects who received the reference standard, makes this evidence insufficient to draw conclusions.

According to the American Cancer Society, breast cancer is the second largest cancer killer of women behind skin cancer. It is the leading cause of death for women between the ages of 35-44. An estimated 2 million women are currently living with breast cancer and an additional 178,480 new cases of invasive breast cancer will be diagnosed during 2007. As many as 40,460 women are suspected to have died of breast cancer in 2007.

Regular annual screening using mammography for women at risk of developing breast cancer has been shown to help identify breast cancer at an earlier stage, and has aided in the decline of the breast cancer-related mortality rate significantly. Self-exam has also been shown to be of use but should not be used as an alternative to a proper mammogram.

Mammographic abnormalities can be stratified into categories called BI-RADS (Breast Imaging Reporting Data System), which reflect the risk of malignancy given the mammographic appearance. Scores range from one to five as follows:

BI-RADs Terminology

When an individual presents with a BI-RADs score of three or four, there may be some uncertainty regarding the necessity for further biopsy to determine the presence of cancer. In an attempt to decrease the need for an invasive tissue biopsy, methods to further classify suspected lesions found on mammograms are being sought. Electrical impedance of the breast is one such technology.

Electrical impedance scanning of the breast involves the transmission of a continuous low level electrical current through the body, using either an electrically charged skin patch attached to the arm or a hand-held cylinder. The electrical current travels through the body to a location where it is most easily transmitted out. When a special skin probe is placed on the breast, the current will flow through.  The current is then measured at many locations on the breast and a computer attached to the probe records the results. The computer then calculates various parameters and creates an image of breast tissue composition.

The basic principle of this technique is that cancerous tissue conducts electricity differently than normal tissue. As the probe is placed over various locations on the breast, the electrical impedance encountered by the probe, changes if cancerous tissue is encountered. This change in impedance, corresponding to the location of a cancerous lesion, is then represented as a bright white spot on the computerized image.

Currently, there is only one electrical impedance device with FDA approval for use as an adjunct to mammography. The T-Scan™ 2000 received approval from the U.S. Food and Drug Administration (FDA) in 1999. However, the use of this device is not considered part of the standard of care in clinical practice at this time.

Electrical impedance: a measurement of resistance to the flow of electricity between two points; this technique may be used to measure various aspects of physiological and physical properties of the body

The following codes for treatments and procedures applicable to this policy are included below for informational purposes.   Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services are Investigational/Not Medically Necessary:

CPT

ICD-9 Diagnosis

Peer Reviewed Publications:

1. De Bie RA, de Vet HC, Lenssen TF, Van den Wildenberg FA, et al. Low-level laser therapy in ankle sprains: a randomized clinical trial. Arch Phys Med Rehabil. 1998; 79(11):1415-1420. 
2. Hope TA, Iles SE. Technology review: the use of electrical impedance scanning in the detection of breast cancer. Breast Cancer Res. 2004; 6(2):69-74.
3. Malich A, Boehm T, Facius M, et al. Differentiation of mammographically suspicious lesions: evaluation of breast ultrasound, MRI mammography and electrical impedance scanning as adjunctive technologies in breast cancer detection. Clin Radiol. 2001; 56(4):278-283.
4. Malich A, Fritsch T, Anderson R, et al. Electrical impedance scanning for classifying suspicious breast lesions: first results. Eur Radiol. 2000; 10(10):1555-1561.
5. Malich A, Bohm T, Facius M, et al. Additional value of electrical impedance scanning: experience of 240 histologically-proven breast lesions. Eur J Cancer. 2001; 37(18):2324-2330.
6. Martin G, Martin R, Brieva MJ, Santamaria L. Electrical impedance scanning in breast cancer imaging: correlation with mammographic and histologic diagnosis. Eur Radiol. 2002; 12(6):1471-1478.
7. Perlet C, Kessler M, Lenington S, et al. Electrical impedance measurement of the breast: effect of hormonal changes associated with the menstrual cycle. Eur Radiol. 2000; 10(10):1550-1554.
8. Stojadinovic A, Moskovitz O, Gallimidi Z, et al.  Prospective study of electrical impedance scanning for identifying young women at risk for breast cancer. Breast Cancer Res Treat. 2006. 
9. Wersebe A, Siegmann K, Krainick U, et al. Diagnostic potential of targeted electrical impedance scanning in classifying suspicious breast lesions. Invest Radiol. 2002; 37(2):65-72.

Government Agency, Medical Society, and other Authoritative Publications:

1. United States Food and Drug Administration. Summary of effectiveness for TransScan T-Scan 2000. Available at:  http://www.fda.gov/cdrh/pdf/p970033.html.  Accessed on March 1, 2007.

1. American Cancer Society. All About Breast Cancer. Available at:  http://www.cancer.org/docroot/CRI/CRI_2x.asp?sitearea=LRN&dt=5. Accessed on March 1, 2007.
2. American Cancer Society. Mammograms and Other Breast Imaging Procedures. Available at:    http://www.cancer.org/docroot/PED/content/PED_2_3X_ Mammography_and_Other_Breast_Imaging_Procedures.asp. Accessed on March 1, 2007.

Breast Cancer
Electrical Impedance Scan
Risk Assessment
T-Scan™ 2000

The use of specific product names is illustrative only.  It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.
 

Federal and State law, as well as contract language, including definitions and specific contract provisions/exclusions, take precedence over Medical Policy and must be considered first in determining eligibility for coverage. The member's contract benefits in effect on the date that services are rendered must be used. Medical Policy, which addresses medical efficacy, should be considered before utilizing medical opinion in adjudication. Medical technology is constantly evolving, and we reserve the right to review and update Medical Policy periodically.

No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise, without permission from the health plan.

©CPT Only - American Medical Association