Investigation of Bioimpedance Capacitance in Patients with Breast Cancer-Related Lymphedema on the Basis of Weibull Analysis.

Bioimpedance analysis constitutes noninvasive, low-cost intervention for early diagnosis and evaluation of breast cancer-related lymphedema (BCRL). In this study, we investigated the frequency dependence of capacitance, a marker of disease progression, in patients with BRCL. Pseudo membrane capacitance of the affected and unaffected sides of upper limbs was calculated from reactance values obtained at 5, 50, and 250 kHz. At all frequencies, pseudo membrane capacitance differed significantly between affected and unaffected limbs, with the most pronounced difference observed at 5 kHz. The Weibull analysis of the 5 kHz data demonstrated linear distributions for both limbs, with high correlation coefficients (affected: r = 0.97; unaffected: r = 0.98). The shape parameter derived from the Weibull plot indicated that pseudo membrane capacitance on the unaffected side followed a Gaussian-like distribution (α = 3.90), whereas that on the affected side was characterized by a Rayleigh distribution (α = 2.04). These distributional differences suggest distinct underlying tissue characteristics between affected and unaffected limbs. These findings indicate that capacitance measured using commonly available bioimpedance devices can differentiate affected from unaffected limbs and may provide clinically relevant information for identifying early or subclinical lymphedema prior to the development of overt clinical edema.