Can Tissue Stiffness Measured Using Shear-Wave Elastography Represent Lymphedema in Breast Cancer?

Background: Lymphedema causes skin and subcutaneous fibrosis. However, quantitative methods for estimating the severity of fibrosis due to lymphedema have not been established. We evaluated skin stiffness using shear-wave elastography (SWE) and aimed to identify stiffness-associated factors in patients with breast cancer-related lymphedema (BCRL). Methods and Results: Thirty-six women (mean age, 57.5 ± 1.78 years; range, 39-77 years) were retrospectively recruited for this study. The mid-arm and mid-forearm circumferences were measured. The percentage differences in arm and forearm circumferences were used as an indicator of the severity of lymphedema at the time of SWE measurement and the measurement taken when the symptoms were most severe. Not subcutaneous tissues but cutaneous tissues of the affected arm and forearm showed a significant increase in shear-wave velocity (SWV) compared with those of the unaffected side. However, SWV was not correlated with the severity of lymphedema as a percentage difference when symptoms were most severe. Body mass index and lymphedema duration showed no significant correlation with the SWV of cutaneous tissues on the affected upper extremities. Conclusions: SWE can adequately estimate cutaneous fibrosis between the affected and unaffected limbs in patients with BCRL. However, evaluation of subcutaneous fibrosis is limited. Therefore, SWE can be an effective tool for evaluating cutaneous fibrosis in patients with BCRL.