Contrast‐Enhanced Ultrasound Evaluation of Lymphatic Function in Breast Cancer‐Related Lymphedema

OBJECTIVE: This study aimed to compare contrast-enhanced ultrasound (CEUS) parameters of lymphatic vessels between patients with breast cancer-related lymphedema (BCRL) and healthy controls. We introduced subcutaneous lymphatic capillary backflow (SLCBF) as a novel CEUS parameter to evaluate the ability of CEUS to distinguish abnormal from normal lymphatic function. METHODS: Clinical and lymphatic CEUS data were prospectively collected from 50 participants, including 38 patients with BCRL (abnormal group) and 12 healthy volunteers (normal control group). Differences in lymphatic CEUS parameters between the two groups were compared, and the correlation between SLCBF and ISL stage was analyzed to evaluate the utility of CEUS in assessing lymphatic function. RESULTS: Compared with the normal control group, the BCRL group exhibited a significantly greater number of visualised collecting lymphatic vessels (CLVs), as well as larger values for both the mean internal diameter and the internal diameter of the thickest CLVs (all p < 0.05). SLCBF was visualised in all BCRL patients with varying degrees of enhancement, whereas no enhancement was detected in any normal control. Further analysis revealed that the SLCBF grade was strongly correlated with the ISL clinical stage (r = 0.64, p < 0.05) and also showed significant positive correlations with both the internal diameter of the thickest CLVs (r = 0.67, p < 0.05) and the mean internal diameter of CLVs (r = 0.65, p < 0.05). CONCLUSION: This study identified SLCBF as a characteristic manifestation of lymphedema, which was present in all BCRL patients but entirely absent in healthy volunteers. CEUS clearly visualizes the full pathological spectrum from this early sign to late structural damage, offering a valuable tool for the early diagnosis and precise assessment of lymphedema.