Charcoal localization of metastatic axillary lymphadenopathy in breast cancer patients: concordance with sentinel lymph node biopsy.

BACKGROUND

Accurate identification and localization of axillary lymph node involvement in breast cancer before therapeutic interventions, such as neo-adjuvant chemotherapy or surgery, are for optimal disease management. This study evaluates the concordance between charcoal-based localization of axillary lymphadenopathy and sentinel lymph node biopsy.

METHODS

In this cohort study, 70 patients with breast cancer and up to three metastatic axillary lymph nodes were enrolled at Omid Hospital's radiology department. Nodes were marked with 0.2-0.3 mL charcoal injection under ultrasound guidance. After completion of neoadjuvant chemotherapy, preoperative lymphoscintigraphy was performed. The frequency of positive lymph nodes identified by charcoal staining was compared with the sentinel lymph node findings during surgery.

RESULTS

Post-surgical pathology identified charcoal in 89 nodes across 64 patients, yielding a detection rate of 91.4% (95% CI: 85-98%). Among the 64 patients with charcoal- contained nodes, 56 were SLNs containing charcoal, and 8 were non-SLNs, resulting in a concordance rate of 87.5% (95% CI: 79.4%-96%). A chi-square test confirmed a significant association between charcoal-tattooed nodes and SLNs concordance (χ² = 12.3, p < 0.001).

CONCLUSIONS

This study demonstrated that ultrasound-guided charcoal tattooing of metastatic axillary lymph nodes before Neoadjuvant chemotherapy is a safe, low-cost, and effective technique for localization of limited nodal involvement in breast cancer patients, with high concordance with sentinel lymph node biopsy.