Patterns of Temporal Changes in Tissue Dielectric Constant as Indices of Localized Skin Water Changes in Women Treated for Breast Cancer: A Pilot Study

Harvey N. Mayrovitz, Daniel N. Weingrad, and Lidice Lopez. Lymphatic Research and Biology Volume 13, Number 1, 2015

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Patterns of Temporal Changes in Tissue Dielectric Constant as Indices of Localized Skin Water Changes in Women Treated for Breast Cancer: A Pilot Study

Harvey N. Mayrovitz, Daniel N. Weingrad, and Lidice Lopez. Lymphatic Research and Biology Volume 13, Number 1, 2015

Background: Our goal was to characterize temporal patterns of skin Tissue Dielectric Constant (TDC) as a foundation for possible TDC use to detect and quantify lymphedema. Although limb volumes and bioimpedance analysis (BIA) are used for this purpose, potential TDC-method advantages are that it can be done in about 10 seconds at any body site to depths from 0.5 to 5.0mm below the epidermis.

Methods and Results: TDC at forearm, biceps, axilla, and lateral thorax, and BIA values and arm volumes were measured in 80 women with breast cancer prior to surgery and in decreasing numbers at 3, 6, 12, 18, and 24 months post-surgery. Results show that TDC values, reflecting water content in the measurement volume, vary by site and depth but that at-risk/contralateral side ratio (A/C) is relatively independent of site and depth and is the preferred TDC parameter to detect tissue water changes over time in unilateral conditions. Among sites measured, lateral thorax, followed by forearm, appears most useful for TDC measurements with axilla least useful. Pre-surgery TDC inter-side values and A/C ratios showed no significant inter-side differences, suggesting that breast cancer presence per se did not alter tissue water status in this patient population. Sequential changes in TDC A/C ratios detected a greater number of patients who had inter-arm ratio increases exceeding 10% than were detected using BIA ratios. This may indicate a greater sensitivity to localized tissue water changes with the TDC-method.

Conclusions: TDC is a technically viable and potentially useful method to track skin water changes in persons treated for breast cancer.

Main findings

  • Of the 80 subjects only 35 subjects were evaluated at all the stages of the study.
  • The following objective measurements were taken:
    • Tissue Dielectric Constant (TDC). Bilateral TDC values were measured at four sites using the MoistureMeter-D (Delfin Ltd. Kupio, Finland). Measurements were done in the following order: 1) anterior forearm (6cm distal to the antecubital fossa); 2) anterior biceps (8cm proximal to the antecubital fossa); 3) within the axilla center; and 4) at the lateral thorax (10cm inferior to the axilla).
    • Arm volumes were calculated by measuring arm girths (circumferences) at 4cm intervals with a spring tension tape measure and calculating volume from the sum of segmental volumes.
    • Arm BIA values were determined with the Imp-XCA device (ImpediMed Ltd, Australia). Measurements were done according to manufacturer’ instructions.
  • Among anatomical sites evaluated, the lateral thorax, followed by anterior forearm, appears to be useful for TDC measurements but measurements at the axilla appear to be least useful.
  • Measured pre-surgery TDC inter-side values and at-risk/contralateral side ratios show no significant inter-side differences, thereby suggesting that the presence of the breast cancer itself did not alter the tissue water status in the present population.
  • Sequential changes in TDC ratios show a greater number of patients being detected with inter-arm ratio increases exceeding 10% than detected using BIA ratios. This may indicate a greater sensitivity to localized tissue water changes with the TDC method.