Evaluation of Magseed as Localization Device for Biopsy Proven Metastatic Axillary Lymph Nodes

Part 1: Ten women with biopsy proven breast cancer and metastasis to an axillary lymph node
will have a Magseed placed into the metastatic lymph node AFTER neoadjuvant chemotherapy
(NAC) and just prior to surgery. These patients will have a non-contrast enhanced breast MRI
development study to evaluate and identify ways to reduce the artifact in the axilla created
by the Magseed. Efficacy of the localization with the Magseed will be available within a week
of the placement.

Part 2: Ten additional women with biopsy proven breast cancer and metastasis to an axillary
lymph node will have a Magseed placed into the metastatic lymph node BEFORE NAC. These
patients will have routine contrast enhanced MRIs, mammograms, and ultrasounds before and
after NAC to evaluate treatment response.

Seed placement: Once a patient has been identified eligible for the research study and has
provided written informed consent the patient will have a Magseed placed into the biopsy
proven lymph node. The Magseed delivery system is identical to the investigators' current
practice using radioactive seeds. The seed is pre-loaded into the needle and is inserted into
the lymph node following local anesthesia with 1% lidocaine. Once the seed is deployed, post
procedure seed location is confirmed sonographically and mammographically with tomosynthesis.

MRI: Ten no-charge limited non-contrast breast MRIs for research development purposes are
available for this study through the radiology department. Phase 1 participants will enroll
in the study after their pre- and post-NAC imaging has already been performed per routine
clinical practice. These participants will have a single non-contrast enhanced breast MRI
using the investigators' standard non-contrast sequences (axial ideal T1 and T2-weighted,
axial STIR, and axial 3D vibrant using a dedicated breast coil, FOV 28 cm or to fit the
patient size, and an image-thickness/image-increment of 5mm/1mm). A physicist will
participate in the scanning of these patients to evaluate the extent of artifact in the
axilla and adjacent breast tissue and optimize scanning parameters to reduce this artifact.

Phase 2 participants will enroll in the study prior to NAC and have routine contrast enhanced
breast MRIs performed before and after NAC. Clinically indicated MRI scans will be charged to
the patient's insurance company as this imaging is standard clinical practice. The MRI
protocol will use the investigators' standard clinical sequences (axial ideal T1 and
T2-weighted, axial STIR, and axial 3D vibrant using a dedicated breast coil). Once contrast
is injected (gadobutrol 10mmol/10mL) 3D vibrant sequences will be obtained four times after
contrast injection (FOV 28 cm or to fit the patient size, and an
image-thickness/image-increment of 5mm/1mm).

Mammogram: Patients enrolled in the research study will have standard mammographic imaging
before and after NAC, which will include both the breast and axilla as per routine clinical
protocol.

Ultrasound: Patients enrolled in the research study will have standard sonographic imaging
before and after NAC of the breast and axilla as per routine clinical protocol. Post-NAC
ultrasound of the axilla will be a supplemental assessment to breast MRI as the Magseed
artifact may obscure these findings.

Seed Removal: As per the current practice, patients will have targeted axillary lymph node
dissection including both the localized lymph node and sentinel lymph node. Identifying the
lymph node containing the Magseed will require the Sentimag handheld probe in the operating
room. This device which functions similar to the gamma probe has been approved for an
equipment trial starting in August of 2018. Once the lymph node has been excised a specimen
radiograph will be obtained to verify removal.

Inclusion Criteria:

1. Women 18 years or older

2. Neoadjuvant chemotherapy planned prior to surgical excision

3. Scheduled for target axillary lymph node dissection including the localized lymph node
and sentinel lymph node

Exclusion Criteria:

1. Pregnant or nursing women

2. Allergy to lidocaine or gadolinium

3. Contraindication to MRI (i.e. pacemaker)

4. Axillary Infection

5. Prior axillary radiation

6. Known allergy to bone wax, beeswax or propolis