Role of handedness on forearm skin tissue dielectric constant (TDC) in relation to detection of early‐stage breast cancer‐related lymphedema

Summary skin tissue dielectric constant (TDC) measurements help assess local skin water to detect incipient early‐stage lymphedema subsequent to breast cancer treatment‐related lymphedema. However, presurgery measurements are not always obtained and assessments for evolving lymphedema are only made after surgery. Thus, subsequent TDC assessments may be biased in an unknown way dependent on a patient's handedness in relation to the at‐risk arm. We investigated this issue by comparing TDC values in dominant and non‐dominant volar forearms of 31 left‐handed women and 31 right‐handed women (age range 24–84 years). Body fat and water percentages were assessed by bioimpedance at 50 KHz. Results showed that TDC values of dominant versus non‐dominant arms did not significantly differ for left‐handers or for right‐handers. There was also no statistically significant difference in absolute TDC values between left‐ and right‐handers or a statistically significant difference in dominant‐to‐non‐dominant arm ratios between left‐ and right‐handers. For the composite data set (N = 62), TDC values for dominant and non‐dominant arms were, respectively, 30·0 ± 4·6 and 29·6 ± 4·2 and the dominant‐to‐non‐dominant arm TDC ratio for combined left‐ and right‐handers was 1·015 ± 0·075. These results suggest that handedness is not a major factor when assessing lymphedema status in women who have previously been treated for breast cancer but for whom pretreatment TDCvalues have not been obtained. Moreover, these results suggest that threshold ratios of incipient subclinical unilateral lymphedema based on interarm TDC ratios apply independent of a patient's handedness for the site and tissue depths herein measured.