Confirmation of the reference impedance ratios used for assessment of breast cancer-related lymphedema by bioelectrical impedance spectroscopy

Background: Breast cancer-related lymphedema in the arm is commonly detected by bioelectrical impedance spectroscopy as an increased inter-arm impedance ratio due to the presence of excess lymph in the at-risk arm relative to that of the unaffected arm. The presence of lymphedema is determined by a value of this ratio greater than the mean ratio, plus three standard deviations observed in a comparable healthy population. This threshold value has not been established using the measurement protocols in current practice. The aim of the present study was to determine the reference range of the inter-arm impedance ratio to allow a cut-off value to be established as a criterion for the detection of breast cancer-related lymphedema