Breast Lesion Localisation Procedure

What is localisation of a breast lesion?

When you attended the breast clinic an abnormal area was found in one of your breasts. You will
have already had a biopsy that shows an area that needs to be removed for further diagnosis and
treatment.
This abnormal area of breast tissue can be seen either on the mammogram pictures or by
ultrasound, but cannot be easily felt by the surgeon. The radiologist will use the mammogram or
ultrasound machine to pinpoint this area of tissue by inserting a magnetic or electromagnetic
reflector seed through a needle into the breast so that the surgeon can remove the abnormality
accurately. The surgeon will be able to precisely detect the position of these seeds during surgery
using special equipment. In certain cases, your surgeon may ask the radiologist to insert a special
flexible wire into the lesion, depending on the circumstances this older technique can sometimes
allow more accurate and precise removal of the lesion.

How is it done?

You will be asked to attend the breast clinic before your forthcoming surgery or the day before your
surgery is scheduled.

Mammogram Localisation:

Using the mammography machine, you will be asked to either to sit or lie down while you are having
the localising device inserted. The compressed paddle from the mammography machine is used
during the localisation, this helps prevent movement as it is important that you remain very still
during the procedure. The radiologist will use the mammogram images taken to identify the
abnormality. Once the images have identified this area, they will inject the skin over the area, using
local anaesthetic (this can sting a little). When this area of your breast is numb, a needle will be
inserted into or around the lesion to be removed and the radiologist will inject a tiny magnetic or
reflector seed into the breast tissue. The needle is then withdrawn and a small dressing is applied.
The wound is only a needle prick and heals very quickly. If a wire specifically is requested by your
surgeon, then the radiologist advances a very thin wire down the needle instead of a
magnetic/reflector seed. Once the wire-tip is just through the lesion the wire deploys a small anchor
at its tip and the needle is withdrawn leaving the wire in place. The wire is difficult to move because
of the anchor on the end, however, once the wire is positioned every care must be taken not to
knock the breast. The compression paddle will be removed.
If a wire is used, its other end is left out of the breast but it will be coiled under a dressing, applied
by the radiographer. Two final mammogram pictures are taken to ensure that that the wire or the
seed is in the correct position. Keeping the wire in your breast for a few hours prior to surgery is not
painful. The magnetic/reflector seed is never painful and no particular care is needed afterwards.
The advantage of the magnetic/reflector seed is that it can be performed any time before your
surgery whereas wire insertion must be done within 24 hours prior to surgery because some length
of the wire comes out of the skin until surgery is performed.

Ultrasound Localisation:

Using the ultrasound machine, you will be lying down on the couch. The radiologist will then scan
the area and accurately locate the abnormality within the breast tissue. In a similar way to the
mammogram localisation, the breast will be numbed with local anaesthetic and then the needle will
be positioned within the breast and abnormality. The magnetic/reflector seed or wire will be placed
as explained earlier.
The radiologist may also draw the exact area using a surgical marker pen to aid the surgeon.
Two mammograms will then be taken to confirm positioning of the localising seed or wire. The local
anaesthetic will ensure that any discomfort you might feel will be kept to a minimum throughout the
full examination. A radiographer will also be with you during the localisation, in case you have any
worries.
Ultrasound localisation is more comfortable and straightforward because it does not require you to
be in the mammography compressed paddle while the localising seed/wire is inserted but is only
possible if the lesion to be localised is actually visible on ultrasound, which is not always the case.
If a wire is used, keeping the wire in your breast for a few hours prior to surgery is not painful.
All magnetic/reflector seeds and/or wires are removed during the surgical procedure.
After the procedure

You will need to keep the area and dressing dry, so we do not recommend showering after this
procedure.