Correlation between the drainage time in dynamic indocyanine green lymphography (ICG) and axillary lymph nodes metastatic involvement in breast cancer patients-a prospective study.

[PURPOSE] Axillary lymph nodes dissection (ALND) carries several complications, prompting the search for less invasive methods, especially after neoadjuvant chemotherapy. This study investigated the correlation between dynamic indocyanine green (ICG) lymphography drainage time of the upper limb and the pathological stage of axillary metastatic involvement. We hypothesized that prolonged ICG drainage time correlates with higher nodal burden.

[METHODS] 45 female breast cancer patients undergoing ALND were enrolled. Dynamic ICG lymphography was performed the day before surgery, with intradermal injections in both upper limbs. ICG drainage time to the axillary region was recorded. Pathological and clinical lymph nodes stages (cN/(y)pN) were determined. Statistical analyses included ANOVA, t-tests, and ROC analysis were performed.

[RESULTS] The mean ICG drainage time was 625.6 ± 199.0 s. A statistically significant correlation was found between ICG drainage time and (y)pN stage (p < 0.05). Patients were categorized into low-burden ((y)pN0 + (y)pN1)-33 patients, and high-burden ((y)pN2 + (y)pN3) group-12 patients. Drainage time was significantly delayed in the high-burden group (525.8 ± 103.3 s vs. 900.1 ± 134.3 s; p < 0.001). No significant difference was observed between (y)pN0 and (y)pN1. ROC analysis demonstrated a high discriminatory ability for differentiating between low and high nodal burden (AUC 0.995), with an optimal cut-off of 695 s. No correlation was found with time of drainage and cN, tumor biological features, age, BMI, or arm circumference.

[CONCLUSION] Dynamic ICG lymphography drainage time correlates with pathological axillary nodal metastatic burden in breast cancer patients, particularly differentiating between low and high nodal involvement. This non-invasive functional assessment holds promise as a valuable adjunct for precise axillary management, guiding surgical de-escalation strategies, and potentially identifying patients at higher risk for lymphedema.