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Many tests have been developed to find breast cancer early. Tests, such as mammography, ultrasound and magnetic resonance imaging (MRI), can show abnormalities in the breast that cannot be felt by a woman or her doctor.
If an abnormality that cannot be easily felt needs to be surgically removed, surgeons need a marker to guide to the correct area of breast tissue. A hookwire localisation is where a fine wire, called a hookwire, is placed in the breast with its tip at the site of the abnormality.
Before surgery is carried out, a specialist doctor (a radiologist) places the hookwire into the correct position in the breast using ultrasound, mammography or MRI for guidance. The ‘hook’ at the end of the wire prevents the wire from moving out of position before surgery.
Breast hookwire localisation is carried out using local anaesthetic to numb the breast in the area where the hookwire is to be inserted.
If you have an abnormality in your breast that cannot be easily felt, but requires surgical removal, a hookwire can be used as a marker for the surgeon, with its tip at the site of the abnormality. A hookwire is similar to the surgeon having a map of exactly where to find the lump before beginning the operation, and can make the operation quicker and more accurate.
Usually, this procedure will be carried out a few hours (or less) before you have surgery to remove the abnormality. There is no preparation required for the hookwire localisation.
You should bring with you to the hookwire localisation any recent mammograms, ultrasounds or MRI scans and the reports, so these can be reviewed by the radiologist before your procedure. Your surgeon will organise how this should be arranged (whether you bring them on the day or whether they are forwarded to the radiologist in advance).
The radiologist will choose the method of imaging guidance for the localisation (i.e. mammography, ultrasound or MRI), usually depending on which type of imaging originally found the abnormality, and which type of imaging shows the area more clearly.
You will be positioned comfortably in a chair at the mammography machine. A mammogram will be carried out with the breast placed between two plates and compressed, and the radiologist will find the abnormality. The breast remains compressed for the duration of the procedure. The breast is washed with antiseptic and the radiologist will place a very fine needle into the breast with local anaesthetic to numb the area where the hookwire is to be inserted.
The radiologist will then insert a fine needle into the breast tissue that is to be removed. Mammographic images are taken to check the needle is in the correct position and the needle is adjusted as required. Once the needle is in the correct position, a fine wire is passed down the centre of the needle and the needle is removed, leaving the wire in place. A final mammogram is carried out to show the surgeon where the tip of the wire lies in relation to the abnormality that is to be removed.
You will lie comfortably on an examination couch and the radiologist will find the abnormality using images taken with the ultrasound probe (a small smooth hand-held device that is moved backwards and forwards across the skin of the breast). The breast is washed with antiseptic, and the radiologist will place a very fine needle into the breast with local anaesthetic to numb the area where the hookwire is to be inserted.
The radiologist will then insert a fine needle into the tissue that is to be removed. The position of the needle is checked using the ultrasound images. Once the needle is in the correct position, a fine wire is passed down the centre of the needle and the needle is removed, leaving the wire in place. A final mammogram is carried out to show the surgeon where the tip of the wire lies in relation to the abnormality that is to be removed (a mammogram provides a better visual image for the surgeon of where the tip of the wire lies than ultrasound).
An intravenous line (a thin plastic tube) will be inserted, usually into a vein in the arm or back of the hand or wrist. You will then be positioned on a bed that moves in and out of the MRI scanner. The breast will be lightly compressed from the side by a small plastic plate (this is less than the compression for a mammogram). An injection of dye or contrast medium will usually be given into the intravenous line to highlight and provide a clearer picture of the breast area on the MRI images. A set of MRI scans will be carried out.
The breast is washed with antiseptic, and the radiologist will place a very fine needle into the breast with local anaesthetic to numb the area where the hookwire is to be inserted. The radiologist will then insert a plastic needle (so that it is compatible with the strong magnetic field used in MRI) into the abnormal tissue. Once the needle is in the correct position, a fine wire is passed down the centre of the needle and the needle is removed, leaving the wire in place. The MRI scanner produces pictures to show the surgeon where the tip of the wire lies in relation to the abnormality that is to be removed.
Whichever method is used for guidance of the hookwire placement, a piece of the fine wire is left sticking out from the breast. After the procedure, this piece of wire is taped down to the skin, and the hookwire remains in the abnormality in the breast. The surgeon will remove the wire together with the abnormality at the time of the operation. Your previous imaging and the images from the breast hookwire localisation will be sent with you to the operating theatre, so that the surgeon can refer to them.
As the hookwire will be removed at the time of the operation, there are no after effects of the procedure itself.
The most common problem encountered is that some women may faint or feel light-headed during the procedure, which might be related to stress.
You can talk to your doctor or the hospital or radiology practice about how you can help to reduce your stress levels before having the procedure. If you feel unwell (in other words, like you might faint) during or after the procedure, tell the radiologist or staff where you are having the procedure carried out. Measures can be taken (like elevating your legs or even giving you a small injection of atropine medication) that will greatly decrease the chance of fainting.
Mammographic- and ultrasound-guided hookwire localisation take approximately 30 minutes. An MRI-guided procedure requires approximately 45 minutes.
Hookwire localisation is a simple procedure and most women have no problems. Some problems that can occur are:
Hookwire localisation assists a surgeon in the removal of breast abnormalities that cannot be felt. It marks where the abnormal tissue is located and enables the surgeon to remove even the smallest amount of abnormal tissue identified on mammograms, ultrasound or MRI scans. As only the abnormal tissue is removed (with a margin of clear tissue around it), scarring can be minimised and the shape of the breast can be preserved as far as possible. This also reduces the time taken for the operation to be completed, which is important when you are having a general anaesthetic.
The team carrying out the hookwire localisation procedure will usually be a nurse, a radiographer (the technologist who takes the mammograms, ultrasound or MRI images) and a radiologist (the specialist doctor who reads the images and carries out the hookwire localisation).
Ideally, the procedure is done in the radiology department of the hospital where you are to have your surgery. Occasionally, when the surgical centre does not have the necessary radiology facilities, the procedure is carried out at a radiology centre in a hospital or private radiology practice where the facilities are available. This is more common for MRI-guided procedures.
If your localisation is not carried out at the surgical centre, you will need to organise transport from the radiology facility to the surgical centre. It is usually best to arrange the shortest, most direct route, and transport by car is preferable. Too much movement may lead to dislodgement of the wire, as described in the question above on risks.
The hookwire procedure is a guide for the surgeon. As it is not an investigation, there are usually no results for the hookwire procedure itself, other than a written description of what was done and the guidance images. The surgeon will give you the pathology results (where the abnormal tissue is examined for any disease) for the tissue removed when you have your appointment with the surgeon after the operation.
Page last modified on 19/12/2019.
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RANZCR® intends by this statement to exclude liability for any such opinions, advices or information. The content of this publication is not intended as a substitute for medical advice. It is designed to support, not replace, the relationship that exists between a patient and his/her doctor. Some of the tests and procedures included in this publication may not be available at all radiology providers.
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