Relationship Between the Circumference Difference and Findings of Indocyanine Green Lymphography in Breast Cancer-Related Lymphedema

Background Breast cancer-related lymphedema (BCRL) is a common complication. Indocyanine green (ICG) lymphography has been performed to assess lymphatic functionality. We found that some BCRL patients had a difference in circumference in partial regions only. The purpose of this study was to evaluate the patients with BCRL about the correlation between the difference in circumference and the findings of ICG lymphography. Methods One hundred fifty-five patients with unilateral BCRL were enrolled in this study. We evaluated the differences in circumference taken at 4 parts on the upper limb (at around the wrist, forearm, elbow, and brachium). The difference in circumference was evaluated between the affected part (C-af) and the unaffected part (C-un). We calculated the circumference difference rate (CDR) as follows: CDR = 100 (C-af - C-un)/C-af. First, we classified each part of all BCRL patients (620 parts) based on the findings of ICG lymphography (linear, collateral, dermal back flow [DBF], and no enhancement) and evaluated the correlation. Second, in the patients with partial volume change, we compared the mean CDR in each part. Results One hundred six parts were of a linear pattern, 31 parts were collateral, 350 parts were DBF, and 133 parts had no enhancement. The mean CDR of each finding was 3.3% in linear, 4.0% in collateral, 9.6% in DBF, and 9.4% in no enhancement. There was no significant difference between linear and collateral (P = 0.62), DBF, and no enhancement (P = 0.89) patterns. However, there was a significant difference between linear or collateral and DBF or no enhancement (all P < 0.001). In the 22 patients with distal DBF and proximal linear, the CDR was significantly higher in the forearm compared with the brachium (6.4% and 3.0%; P = 0.003). In the 26 patients with distal linear and proximal DBF, the CDR was significantly higher in the brachium compared with the forearm (4.3% and 7.7%; P = 0.005). Conclusions There was a significant correlation between the difference in circumference and the severity of ICG findings.