Usefulness of Ultrasound Assessment of Breast Cancer-Related Lymphedema

Background: Lymphedema, a common side effect of breast cancer treatments, affects 20%-40% of patients. Ultrasound evaluation measures structural change as well as skin and subcutaneous tissue thicknesses to assess lymphedema severity. This study aimed to investigate the usefulness of ultrasound evaluation as an outcome measure of lymphedema in patients with breast cancer. Methods and Results: Thirty-one patients with unilateral breast cancer-related lymphedema were enrolled. Arm circumferences were measured at four points, as the Relative Metric Coefficient of Arm Lymphedema (RMCAL). The thickness of the skin and subcutaneous tissue was measured using ultrasound at four points of the upper arm and forearm, comparing both sides. Subcutaneous echogenicity grade (SEG) and subcutaneous echo-free space (SEFS) grade were assessed following the method described by Suehiro et al. Lymphoscintigraphy evaluated axillary lymph node uptake and dermal backflow. Quality of life was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Breast Cancer Module 23 (EORTC QLQ-BR23). Increase ratios of skin and subcutaneous tissue thickness, SEG, and SEFS were well correlated with RMCAL value. Additionally, the increase ratio of subcutaneous tissue was significantly different according to the abnormality of axillary lymph node uptake on lymphoscintigraphy. However, ultrasound parameters did not significantly associate with functional and symptom scales of EORTC QLQ-BR23. Conclusions: Ultrasound parameters were well correlated with arm circumferences. Furthermore, subcutaneous tissue thickness on ultrasound was significantly related to lymphatic function assessed by lymphoscintigraphy.