SEQUENTIAL PATTERN CHANGES IN TISSUE DIELECTRIC CONSTANT (TDC) TO ASSESS LOCAL SKIN-TO-FAT WATER CHANGES IN WOMEN TREATED FOR BREAST CANCER

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Objective. To assess the utility of sequential TDC measurements to characterize temporal changes in skin-to-fat tissue water as a potential way to detect lymphedema in its earliest stages. Background. Non-invasive quantitative measurements useful for early detection of breast cancer (BC) treatment-related lymphedema (BCRL) are needed. Earliest BCRL changes may occur in skin and subcutis and might be detectible via local skin-tissue water (LTW) changes assessed by TDC measurements at 300 MHz. Methods. Bilateral TDC measurements were made in forearms, biceps, axilla and lateral thorax of 80 women treated for unilateral BC. Also, whole arm water was assessed via bioimpedance. All 80 women were evaluated prior to their surgery (month 0) and followed for up to 24 months post-surgery with 35 evaluated at 3, 6, 12, 18 and 24 months post-surgery. Results. Forearm TDC values monotonically decreased with increasing depth at all months. At-risk (A) and control side (C) ratios (A/C) were near 1.00 at month 0 and showed a peaking at forearm and thorax at 6-months post-surgery but was sustained through 24 months only at thorax. Axilla TDC values showed a minimum at 6-months that was also sustained through 24 months. There was no significant change in whole arm A/C bioimpedance ratio at any month. At 24 months postsurgery, 23% of patients exceeded an A/C threshold ratio of 1.20 at thorax compared to 8.2% at forearm and 8.8% for the bioimpedance. Conclusion. TDC side-to-side ratios at the lateral thorax emerge as the most likely and sensitive parameter for potentially detecting early BCRL. Grants. None