Lymphedema Index Ratio As Predictive Factor of Treatment in Patients with Breast Cancer-Related Lymphedema.

Background: This retrospective observational study aimed to evaluate the lymphedema index ratio to predict the effect of complex decongestive therapy (CDT) in patients with breast cancer-related lymphedema (BCRL) and to establish a lymphedema index ratio cutoff value for the extent of CDT effect. Materials and Methods: All 108 enrolled patients with BCRL underwent volume measurements and bioelectrical impedance analysis before and after CDT. The difference in percent excess volume (PEV) before and after CDT was defined as the therapeutic effect, and each patient was assigned to Groups A, B, or C based on therapeutic effects of 0%-5%, 5%-10%, and 10%-20%, respectively. Results: The mean lymphedema index ratios of Groups A, B, and C were 1.27, 1.38, and 1.46, respectively, with significant differences between the groups (p < 0.01). The cutoff lymphedema index ratio values for diagnosis between Groups A and B and between Groups B and C were 1.277 (sensitivity: 71.7%, specificity: 61.8%) and 1.357 (sensitivity: 76.9%, specificity: 62.1%), respectively. The Spearman coefficients for the linear relationship between lymphedema index ratio and initial PEV and between lymphedema index ratio and therapeutic effect were found to be significant at 0.615 and 0.360, respectively (p < 0.01). Conclusion: The results of this study found that the lymphedema index ratio may predict the volume reduction in patients with BCRL. A less reduction (therapeutic effect <5%) was predicted in patients with a lymphedema index ratio of <1.277, while a greater reduction (therapeutic effect >10%) was predicted in patients with a lymphedema index ratio of >1.357.