A guide to targeted axillary dissection (TAD) with Magseed® and Magtrace®

Patient Guide

What to expect when having a lymph node marked prior to chemotherapy with the Magseed® marker


What is targeted axillary dissection (TAD)?

Targeted axillary dissection (TAD) is a treatment that involves ‘marking’ cancerous lymph nodes in your underarm, using the Magseed® marker, in order to be able to locate them after a course of neoadjuvant chemotherapy – chemotherapy that is given before surgery.

The ability to accurately find and remove these particular lymph nodes will allow your surgeon to better understand how you have responded to the chemotherapy treatment.

In addition to removing these initially cancerous nodes marked with a Magseed®, the TAD technique also involved a procedure called a sentinel lymph node biopsy (SLNB). This involves injecting the Magtrace® lymphatic tracer into the breast to map the lymph nodes in the armpit that are most likely to contain cancer if it has spread.

This approach is becoming more common, as studies have shown that chemotherapy given prior to surgery can shrink the tumour in the breast and turn a cancerous lymph node from ‘node positive’ (containing cancer) to ‘node negative’ (free of cancer). When a patient responds in this way it can allow for much less invasive surgery.

Why have I been recommended for targeted axillary dissection (TAD)?

Your surgeon has chosen to perform ‘targeted axillary dissection’ (also known as TAD) to stage your cancer and more accurately understand how it is responding to chemotherapy.

Ultimately your surgeon wants to avoid as many potential complications as possible during surgery to remove cancerous lymph nodes from your underarm. In many cases, the precision of TAD will help reduce the need for a more invasive procedure.

How the Magseed® marker is used

How will my surgeon mark my lymph node(s)?

Through imaging techniques such as x-ray or a mammogram, your cancerous node(s) will be identified, before the Magseed® is injected in to the node(s) to sit inactive until it’s time for scanning or surgical removal.

During chemotherapy, the Magseed® marker will stay firmly in place within the node it has marked, which means it can be rescanned regularly to see how the lymph node has responded to the therapy.

This gives the surgeon better information about the next steps they need to take. In most cases, your surgeon will then look to remove any node(s) with a Magseed® in.

To learn more about the Magseed® marker, please read our patient guide.

The procedure - what can I expect?

The Magseed® marker is placed into your affected lymph node(s)

With a ‘Magseed® localisation’ procedure you will need to attend a placement appointment within the radiology department of your hospital, often located within the breast centre. You’ll go through to an imaging room, where you will typically discuss the procedure and be prepped for the Magseed® marker placement.

The radiology professional will apply an anaesthetic gel to the area of your body where the marker will be injected. Your radiologist will then either use an ultrasound machine or mammography to identify the lymph node(s) they want to mark.

Once they have found this precise location, they will inject the Magseed® marker into the lymph node, using their imaging system, to ensure the seed is placed accurately and securely. This is a quick procedure that only takes a matter of minutes, so your overall appointment should not take too long.

Once the seed is in place you may be invited to have additional mammograms to ensure the seeds are in the right place. These images with help your surgeon later on in the operating room.

You may find the area of injection a little sore at first, just as you would after receiving any other injection.

Chemotherapy before surgery and re-scanning or screening

Following placement, you may be scheduled for chemotherapy treatment. Now that the Magseed® marker is securely placed in your breast it will not be affected by or affect any other therapy you may receive that attempts to shrink or eliminate the cancer in your lymph node.

Your surgeon may wish to use routine mammograms or ultrasound scanning to monitor the lymph node or the tumour in your breast. It is safe for you to have any medical imaging technique with Magseed® placed in your body.

Thanks to the earlier placement of the Magseed® marker, your surgeon will be able to find the seed placed inside your lymph node with ease – helping them to monitor the effect of your chemotherapy and understand any subsequent surgery required.


With your Magseed® marker already placed in the affected lymph node(s), you won’t have to make additional visits to the hospital leading up to the day of surgery. If your surgeon is also using Magtrace® for the SLNB procedure, on the day of surgery you can go straight to the operating room without having to visit any other departments.

The surgery to remove a node containing a Magseed® marker is a routine procedure for a breast surgeon. This will also be combined with a routine SLNB to also remove any other lymph nodes where cancer might have spread.

During this surgery, your surgeon will use a magnetic probe to locate the previously placed Magseed® marker or the collected Magtrace® liquid – and use the magnetic signal to accurately guide them to find the lymph nodes that need to be removed. Once at the site, the node will be surgically removed, leaving behind as much healthy tissue as possible.

Depending on how you have responded to the chemotherapy treatment, you may only need to remove these two or three lymph nodes and not require more invasive surgery.

After surgery

Once your surgery is complete, your surgeon will send the node(s) for analysis and it may take a few days for the results to be processed.

This can take some time, so if you do not hear back straight after surgery, try not to worry.

Where can I find out more?

If you have any more questions about your surgery, please do ask your surgeon or the hospital team. We have a number of resources around our website which talk about our Magseed® marker and the Magtrace® lymphatic tracer, which you are welcome to read.

We hope that the information above has helped you understand a little more about what’s involved in having cancer staged with the help of the Magseed® and Magtrace®.