Guidance Systems for Breast Biopsy

If a mammogram or ultrasound finds a lesion or mass (lump) in your breast, it may need to be removed. If you or your provider cannot feel the mass, it is called “non-palpable.” When this happens, a guidance system is used to help the surgeon find the mass during surgery.

What is a breast guidance system?

A breast guidance system is when something is put into the lesion or mass that helps the surgeon to know exactly where it is. This makes removing the lesion or mass easier since it can’t be felt. There are a few systems that can be used to “mark” where the mass is in the breast.

These markers are removed with the mass during surgery.

Wire

The wire is placed through the skin and into the mass or lesion on the day of surgery. The wire sticks out of the breast and needs to be taped or secured to the breast. The wire is placed the same day as surgery because of the risk of the wire moving if it is done earlier.

Magnet

These markers are stainless steel and can be found with a magnet during surgery. They can be placed before surgery (up to 30 days prior). Two brand names you may hear your provider use are Molli and MagSeed.

Marker

A marker is a small “seed,” about the size of a grain of rice. It can be placed into the mass before surgery (up to 30 days prior). It has a “reflector” in it that can be found with a wand that uses nonradioactive radar waves. The brand name for this system is called SAVI Scout.

Radiofrequency identification (RFID) Tag

The RFID is a small tag with a unique ID number on it. It is placed into the breast tissue with a long, thin needle sometime before surgery. A handheld reader that uses radio waves is used to find the RFID tag. The brand name for this system is called The LOCalizer.

How are they placed?

Your breast will be numbed using a local anesthetic (numbing medicine). It may sting, but the pain will quickly go away. You will have an imaging test, such as a mammogram or ultrasound to find the mass. A needle with the guidance system inside is inserted into the mass. The guidance system is pushed into the mass and the needle is removed. You will then have another imaging test to make sure it is in the right spot.

How are they removed?

The guidance system is removed with the mass during surgery.

The goal of a breast guidance system is to remove the whole mass with clean margins. This means the whole mass and some normal tissue around the mass is removed. Talk with your provider about what kind of guidance system may be used for your surgery if you have a non-palpable mass.