A Randomized Controlled Double-blinded Study Comparing the Intraoperative Injection of Lymphatic Mapping Agents Tc 99m Tilmanocept to Tc 99m Filtered Sulfur Colloid in Breast Cancer Patients Undergoing Breast Conservation and Sentinel Lymph Node Biopsy

This study is a double-blinded randomized control trial comparing tilmanocept to TSC as intraoperative radiolabeled mapping agents in female patients with early stage breast cancer undergoing partial mastectomy with SLNBx.

To secure this aim, patients who are schedule to undergo partial mastectomy and SLBx will be consented and randomized (randomization table) into one of two experimental arms, tilmanocept or TSC.

These patients will then undergo their scheduled partial mastectomy with SLNBx, with the patient and surgeon blinded to the randomization result.

The respective radiotracers will both be delivered to the OR in the same delivery device and volumes to continue to preserve anonymity of the material. Care will be taken to handle the radiotracers along the standards and guidelines that are already in practice in Memorial Health University Hospital's nuclear medicine department. Two intradermal injections of these radiotracers will be delivered at 3 and 6 o'clock positions at the edge of the areola, after induction of general anesthesia, allowing for less discomfort to the patient.

Methylene blue (5-10 ml) will also be injected in the subareolar space immediately afterwards in all study patients, using a separate syringe, in accordance with the surgeon's current standard practice.