Correlation Between Clinical Assessment and Lymphofluoroscopy in Patients with Breast Cancer-Related Lymphedema: A Study of Concurrent Validity

Background: A disturbance of the superficial lymphatic system (dermal backflow) in patients with breast cancer-related lymphedema (BCRL) can be visualized by near-infrared fluorescence imaging or lymphofluoroscopy. In clinical practice, exact measurement of the dermal backflow is difficult. The purpose of the study is to investigate the concurrent validity between the clinical assessments and the lymphofluoroscopy in patients with BCRL. Methods and Results: Forty-five patients with BCRL stage I to IIb received lymphofluoroscopy and clinical assessments of their edematous limb (pitting status, skinfold thickness, skin elasticity, water content, lymphedema volume, and extracellular fluid). The correlation between the clinical assessments and the result of the lymphofluoroscopy was determined. The best overall agreement with dermal backflow was found for the clinical assessment pitting status, skinfold thickness, and water content. Overall sensitivity was excellent for lymphedema volume (92.5%), high for skinfold thickness (86.6%) and water content (75.0%), and moderate for pitting status (67.7%). Overall specificity was excellent for skin elasticity (94.7%), high for pitting status (83.4%), and moderate for skinfold thickness (61.6%) and water content (74.8%). In the evaluation of the whole arm, measurements of the excess volume were significantly greater for patients in an advanced stage of dermal backflow in comparison with patients in an earlier stage of dermal backflow (p = 0.002). Conclusions: The clinical assessments of skinfold thickness, water content, and lymphedema volume are the most appropriate tools to detect dermal backflow according to the lymphofluoroscopic images. To confirm the absence of dermal backflow, pitting status can be recommended.