Marking the axilla with radioactive iodine seeds (MARI procedure) may reduce the need for axillary dissection after neoadjuvant chemotherapy for breast cancer

BACKGROUND: An important benefit of neoadjuvant chemotherapy is the increased potential for breast-conserving surgery. At present the response of axillary lymph node metastases to chemotherapy is not easily assessed, rendering axilla-conserving treatment difficult. The aim was to assess a new surgical method for evaluating the axillary response to chemotherapy. METHODS: Before neoadjuvant chemotherapy, proven tumour-positive axillary lymph nodes were localized using ultrasound-guided insertion of iodine-125-labelled (I-125) seeds. After neoadjuvant chemotherapy, the marked lymph nodes were removed selectively with the use of a gamma probe. A complete axillary lymph node clearance was carried out to determine whether the pathological response in the marked node was indicative of that in the other lymph nodes. RESULTS: Tumour-positive axillary lymph nodes were localized successfully with I-125 seeds in 15 patients. The marked lymph node was detected and removed selectively after neoadjuvant chemotherapy in all patients. The pathological response to chemotherapy in the marked lymph node was indicative of the overall response in other removed lymph nodes. CONCLUSION: This study showed that marking and selectively removing metastatic lymph nodes after neoadjuvant chemotherapy was feasible. The tumour response in the marked lymph node may be used to tailor further axillary treatment, making axilla-conserving surgery a possibility.