Indocyanine Green Lymphography and Lymphoscintigraphy Severity Stage Showed Strong Correlation in Lower Limb Lymphedema

Background:To examine the correlation between lymphedema severity on lymphoscintigraphy and indocyanine green (ICG) lymphography in patients with secondary lower extremity lymphedema. Methods and Results:The maximal circumference difference (MCD) between the two legs was recorded. Lymphoscintigraphy and ICG lymphography images were classified into type I to V according to dermal backflow (DB) stage and MD Anderson Cancer Center (MDACC) stage based on lymphatic flow preservation and how DB was extended. Correlation between the scales was analyzed. Forty-four patients attended our hospital for evaluation of secondary lower extremity lymphedema. The most common cause of lymphedema was a postoperative complication of a malignant tumor (32 patients; 72.5%). Correlation analysis showed that lymphoscintigraphy and ICG DB (anterior) stage (r = 0.92), lymphoscintigraphy and ICG DB (posterior) stage (r = 0.94), and lymphoscintigraphy and MDACC stage (r = 0.93) exhibited very strong positive correlations. Intrarater agreement between lymphoscintigraphy and ICG DB (posterior) stage was substantial (kappa = 0.65), and moderate between lymphoscintigraphy and ICG DB (anterior) stage (kappa = 0.59) and lymphoscintigraphy and MDACC stage (kappa = 0.52). Lymphedema severity stages and MCDs exhibited moderate positive correlations. Conclusion:Lymphoscintigraphy and ICG lymphography stage were strongly and positively correlated. These studies can work synergistically as complementary studies of lymphedema severity.