Preparing for a Stereotactic Breast Biopsy

What is a Stereotactic Breast Biopsy?

Stereotactic breast biopsy is a non-surgical method of assessing a breast abnormality and is performed by a specially trained radiologist on an outpatient basis. 

A stereotactic breast biopsy is an option when a mammogram shows a breast abnormality such as:

• A suspicious solid mass
• Microcalcifications — tiny clusters of small calcium deposits
• A distortion in the structure of the breast tissue
• An area of abnormal tissue change
• A new mass or area of calcium deposits is present at a previous surgery site

In stereotactic breast biopsy, a special mammography machine uses x-rays to help guide the  radiologist's instruments to the site of the abnormal growth.  Stereotactic mammography pinpoints the exact location of a breast mass by using computer and digital X-rays taken from two different angles.  Using these computer coordinates, the radiologist inserts the needle through the skin, advances it into the lesion and removes tissue samples.

Preparing for a Stereotactic Breast Biopsy

You should not wear deodorant, powder, lotion or perfume under your arms or on your breasts on the day of the exam. 

Prior to a needle biopsy, you should report to your doctor all medications that you are taking (including herbal supplements), and if you have any allergies, recent illnesses or other medical conditions.  Your physician may advise you to stop taking aspirin or a blood thinner before your procedure. 

You may want to have a relative or friend accompany you and drive you home afterward. 

Women should always inform their physician if there is any possibility that they are pregnant because radiation can be harmful to the fetus.

How is a Stereotactic Breast Biopsy Performed?

You may be asked to remove some or all of your clothes and to wear a gown during the exam.  You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the X-ray images or physical comfort. 

You will lie face down on a moveable exam table and the affected breast will be positioned into the opening in the table.  The breast is slightly compressed and held in position throughout the procedure. 

The table is then raised and the procedure is performed beneath it.  Several stereotactic pairs of X-ray images are taken. 

A local anesthetic will be injected into the breast for numbing purposes. 

A very small nick is made in the skin at the site where the biopsy needle is to be inserted.   The radiologist then inserts the needle and advances it to the location of the abnormality using the X-ray and computer-generated coordinates.  X-ray images are again obtained to confirm that the needle tip is actually within the lesion. 

Tissue samples are then removed using a vacuum-assisted device (VAD); vacuum pressure is used to pull tissue from the breast through the needle into the sampling chamber.  Without withdrawing and reinserting the needle, the VAD rotates, positions and collects additional samples.  Typically, eight to ten samples of tissue are collected from around the lesion. 

After this sampling, the needle will be removed and a final set of images will be taken.  A small marker may be placed at the site so that it can be located in the future if necessary. 

Once the biopsy is complete, pressure will be applied to stop any bleeding and the opening in the skin is covered with a dressing.  No sutures are needed. 

A mammogram will be performed to confirm that the marker is in the proper position. 

This procedure is usually completed within an hour.

What Will I Experience During and After the Procedure?

You will be awake during your biopsy and should have little or no discomfort.  Most women report little or no pain and no scarring on the breast. 

When you receive the local anesthetic to numb the skin, you will feel a slight pin prick from the needle. You may feel some pressure when the biopsy needle is inserted.  The area will become numb within a short time. 

You must remain still while the biopsy is performed. 

As tissue samples are taken, you may hear clicks from the sampling instrument. 

If you experience swelling and bruising following your biopsy, you may be instructed to take an over-the-counter pain reliever and to use a cold pack.  Temporary bruising is normal. 

You should contact your physician if you experience excessive swelling, bleeding, drainage, redness or heat in the breast. 

If a marker is left inside the breast to mark the location of a lesion removed during biopsy, it will cause no pain, disfigurement or harm.

You should avoid strenuous activity for 24 hours after returning home, but then will usually be able to resume normal activities.

Who Interprets the Results and How Do I Obtain Them?

A pathologist examines the removed specimen and makes a final diagnosis.  Your referring physician will share the results with you. 

What Are the Benefits vs. Risks?

Benefits

• The procedure is less invasive than a surgical biopsy, leaves little or no scarring and can be performed in less than an hour.
• Stereotactic breast biopsy is an excellent way to evaluate calcium deposits or tiny masses that are not visible on ultrasound.
• Stereotactic core needle biopsy is a simple procedure that may be performed in an outpatient imaging center.
• Compared with open surgical biopsy, the procedure is about one-third the cost.
• Generally, the procedure is not painful and the results are as accurate as when a tissue sample is removed surgically.
• No breast defect remains and, unlike surgery, stereotactic needle biopsy does not distort the breast tissue or make it difficult to read future mammograms.
• The use of a vacuum-assisted device may make it possible to remove the entire lesion.
• Recovery time is brief and patients can soon resume their usual activities.
• No radiation remains in a patient's body after an X-ray examination.
• X-rays usually have no side effects.

Risks

• Because the vacuum-assisted device removes large pieces of tissue, there is a risk of bleeding and forming a hematoma, or a collection of blood at the biopsy site.  The risk, however, appears to be less than one percent of patients.
• An occasional patient has significant discomfort, which can be readily controlled by non-prescription pain medication.
• Any procedure where the skin is penetrated carries a risk of infection.  The chance of infection requiring antibiotic treatment appears to be less than one in 1,000.
• Doing a biopsy of tissue located deep within the breast carries a slight risk that the needle will pass through the chest wall, allowing air around the lung that could collapse a lung.  This is a rare occurrence.
• There is always a slight chance of cancer from radiation.  However, the benefit of an accurate diagnosis far outweighs the risk. 
  Women should always inform their physician or X-ray technologist if there is any possibility that they are pregnant.

What Are the Limitations of Stereotactic Breast Biopsy?

Lesions accompanied by diffuse calcium deposits scattered throughout the breast are difficult to target by stereotactic breast biopsy.  Lesions near the chest wall are also hard to evaluate by this method.  If the mammogram shows only a vague change in tissue density but no definite mass or nodule, this method may not be successful. 

Breast biopsy procedures will occasionally miss a lesion or underestimate the extent of disease present.  If the diagnosis remains uncertain after a technically successful procedure, surgical biopsy will be necessary.