Marking axillary lymph nodes with radioactive iodine seeds for axillary staging after neoadjuvant systemic treatment in breast cancer patients: the MARI procedure.

OBJECTIVE: The MARI procedure [marking the axillary lymph node with radioactive iodine (I) seeds] is a new minimal invasive method to assess the pathological response of nodal metastases after neoadjuvant systemic treatment (NST) in patients with breast cancer. This method allows axilla-conserving surgery in patients responding well to NST. METHODS: Prior to NST, proven tumor-positive axillary lymph nodes were marked with a I seed. This marked lymph node is the so-called MARI-node. After NST, the MARI node was selectively removed using a γ-detection probe. A complementary axillary lymph node dissection was performed in all patients to assess whether pathological response in the MARI node was indicative for the pathological response in the additional lymph nodes. RESULTS: A tumor-positive axillary lymph node was marked with a I seed in 100 patients. The MARI node was successfully identified in 97 of these 100 patients (identification rate 97%). Two patients did not undergo subsequent axillary lymph node dissection, leaving 95 patients for further analysis. The MARI node contained residual tumor cells in 65 of these 95 patients. In the other 30 patients, the MARI node was free of tumor, but additional positive lymph nodes were found in 5 patients. Thus, the MARI procedure correctly identified 65 of 70 patients with residual axillary tumor activity (false negative rate 5/70 = 7%). CONCLUSIONS: This study shows that marking and selectively removing metastatic lymph nodes after neoadjuvant systemic treatment has a high identification rate and a low false negative rate. The tumor response in the marked lymph node may be used to tailor further axillary treatment after NST.

Guiding breast-conserving surgery in patients after neoadjuvant systemic therapy for breast cancer: a comparison of radioactive seed localization with the ROLL technique.

BACKGROUND: Radioguided occult lesion localization (ROLL) with technetium-99 m colloid (ROLL-(99m)Tc) is commonly used to perform breast-conserving surgery in patients with nonpalpable breast tumors. Radioactive seed localization is a relatively new technique that localizes the tumor with a radioactive iodine-125 ((125)I) seed. The feasibility and outcome of these techniques after neoadjuvant systemic treatment has not been widely investigated. METHODS: All patients treated with neoadjuvant systemic treatment between 2007 and 2010 in the Netherlands Cancer Institute who underwent breast-conserving surgery with the ROLL-(99m)Tc technique (n = 83) or with (125)I seed localization (n = 71) were analyzed. The weight of the resected specimen, the margins, and the percentage of patients requiring a second surgical intervention as a result of positive margins were assessed. RESULTS: Patient and tumor characteristics and systemic treatment regimens were comparable between both groups. The median weight of the resected specimen (53 vs. 48 g), the median smallest margin (3.5 vs. 3.0 mm), and the risk for additional surgery for incomplete resections (7 vs. 8 %) did not differ significantly between patients treated with the ROLL-(99m)Tc technique and (125)I seed localization. CONCLUSIONS: The ROLL-(99m)Tc technique and (125)I seed localization demonstrate comparable results when used to perform breast-conserving surgery after neoadjuvant systemic treatment. Because (125)I seed localization does not require additional radiological localization shortly before surgery, it simplifies surgery scheduling. Therefore, we prefer (125)I seed localization to perform breast-conserving surgery after neoadjuvant systemic treatment.