Evaluation of a Novel Axillary Lymph Node Ink Localization Technique: A Feasibility Study

Patients with breast cancer and metastatic axillary lymphadenopathy routinely undergo neo-adjuvant chemotherapy. For these patients, biopsy clip markers are inserted into the biopsy proven metastatic lymph node pre-treatment, as they may reach complete clinical response post-therapy. Limited axillary surgery, as opposed to a full axillary dissection, may then be indicated. It is still necessary to surgically excise the biopsy proven metastatic lymph node to accurately assess the pathologic response to therapy, and subsequently tailor post-surgical therapies appropriately. As such, these lymph nodes require pre-operative localization which, at The Ottawa Hospital, currently requires radioactive seed insertion under sonographic guidance, typically performed within 5 days of surgery. The procedure is often challenging, as both normal appearing lymph nodes and 3 mm biopsy clip markers are difficult and in some cases impossible, to visualize on ultrasound. At the time of surgery, the excised lymph node is radiographed, to ensure the radioactive seed and biopsy clip marker are both successfully excised. Localization with Ink has the potential to replace both the biopsy clip markers and radioactive seeds as the surgeons are able to directly visualize the Ink intra-operatively and excise the Inked lymph node. A preliminary study out of Stanford on 28 patients who underwent localization of axillary lymph nodes with Ink injected 1-211 days pre-operatively, in the pre neo-adjuvant and post neo-adjuvant settings, showed that lymph nodes injected with Ink are visible intra-operatively months after surgery, suggesting that this is a feasible localization technique (1).