TISSUE DIELECTRIC CONSTANT AS AN INDEX OF SKIN WATER IN WOMEN WITH AND WITHOUT BREAST CANCER: UPPER LIMB ASSESSMENT VIA A COMPACT DEVICE

POSTER PRESENTATIONS

Objective. The goals of the study were to utilize the portable device to assess age-related differences of tissue dielectric constant (TDC) between younger healthy women vs. women with breast cancer, upper-arm site differences in women with breast cancer, and the device's limitations of a single measurement vs. averaged triplicate measurements. Background. Previous work showed tissue dielectric constant measurements at 300 MHz useful to evaluate local skin water and showed a new hand-held compact version provided values similar to an original multi-probe system when assessed in healthy subjects. Methods. A total of 84 women were included; 42 were young self-described healthy women and 42 were older women with recently diagnosed breast cancer who were awaiting surgery. In both groups tissue dielectric constant values were assessed on the anterior forearm. Women diagnosed with breast cancer were also measured at the hand, forearm, and biceps with all measurements bilateral and in triplicate. Results. Results showed the following. (1) Forearm TDC values are similar for the younger and older groups with no significant differences (NSD) between groups or between dominant and non-dominant sides or inter-arm ratios. (2) Hand TDC values are 21% greater than forearm and biceps values for hand, forearm and biceps of 1.027+/-0.180, 0.997+/-0.066 and 1.010+/-0.075 respectively. (3) Based on limits of agreement analyses, single TDC measurements are adequate for most forearm and biceps evaluations but multiple measurements are needed for hand measurements. (4) Theoretical detection thresholds for unilateral lymphedema using a 3SD limit of inter-arm ratios are 1.57, 1.20, and 1.24 for hand, forearm, and biceps. Conclusion. These values indicate likely useful forearm and biceps thresholds but are less useful ratio at the hand due primarily to the large variance in hand TDC values among patients. Grants. NA