Image Guided Biopsy (Needle Biopsy)

• What are some common uses of the procedure?
• How should I prepare for the procedure?
• What does the equipment look like?
• How does the procedure work?
• How is the procedure performed?
• What will I experience during and after the procedure?
• Who interprets the results and how do I get them?
• What are the benefits vs. risks?
• What are the limitations of the procedure?

 

Needle Biopsy of a tumor

Usually, a final cancer diagnosis cannot be made until a biopsy is performed. In a biopsy, a sample of tissue from the tumor or other abnormality is obtained and examined by a pathologist. By examining the biopsy sample, pathologists and other experts also can determine what kind of cancer is present and whether it is likely to be fast or slow growing. This information is important in deciding the best type of treatment.

Traditionally, biopsy has required open surgery. With advanced radiology techniques, however, tissue samples usually can be obtained without the need for open surgery.

Image-guided biopsy, also called needle biopsy, is usually performed using a moving X-ray technique (fluoroscopy), computed tomography (CT), ultrasound or magnetic resonance (MR) to guide the procedure. In many cases, image-guided biopsies are performed with the aid of equipment that creates a computer-generated image and allows radiologists to see an area inside the body from various angles. This "stereotactic" equipment helps them pinpoint the exact location of the abnormal tissue. Using this guided imaging, the interventional radiologist inserts a small needle into the abnormal area and removes a sample of the tissue, which is given to a pathologist, who examines it under a microscope. The pathologist can determine what the abnormal tissue is: a non-cancerous tumor, cancer, an infection, or a scar.

What are some common uses of the procedure?

The most common reason for a needle biopsy is to identify the cause of an abnormality inside the body. Imaging tests, such as mammography, ultrasound, a CAT scan (CT), and magnetic resonance imaging (MRI), can find abnormal masses, but these tests alone do not always determine the problem. The needle biopsy can help determine the cause and give your doctor needed information to provide you with the best care and treatment.

How do I prepare for my needle biopsy?

Usually, no special preparation is required. Your doctor will tell you if any special diet or medication instructions are necessary for you. In most cases, you will be an outpatient when you have a needle biopsy. You will arrive at the radiology department for your appointment time and return home after the procedure. The needle biopsy itself usually takes about an hour. If you already are a patient in the hospital, your nurses and doctors will give you instructions on how to prepare for your biopsy.

What does the equipment look like?

A biopsy needle is generally several inches long and the barrel is about as wide as a large paper clip. The needle is hollow so it can capture the tissue specimen.

One of two instruments will be used:

• A fine needle attached to a syringe, smaller than needles typically used to draw blood.
• A core needle, also called an automatic, spring-loaded needle, which consists of an inner needle connected to a trough, or shallow receptacle, covered by a sheath and attached to a spring-loaded mechanism.

Needle biopsies are often performed with the guidance of computed tomography (CT), fluoroscopy or ultrasound.

CT
The CT scanner is typically a large machine with a hole, or tunnel, in the center. You will lie on a table which slides into and out of this tunnel. The x-ray tube and electronic x-ray detectors rotate around you. They are opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate room.

Fluoroscopy
The equipment typically used for this examination consists of a radiographic table, an x-ray tube and a television-like monitor that is located in the examining room or in a nearby room. When used for viewing images in real time (called fluoroscopy), the image intensifier (which converts x-rays into a video image) is suspended over a table on which the patient lies. When used for taking still pictures, a drawer under the table holds the x-ray film or image recording plate that captures the images.

Ultrasound
Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a transducer that is used to scan the body and veins. The transducer is a small hand-held device that resembles a microphone, attached to the scanner by a cord. The transducer sends out high frequency sound waves and then listens for the returning echo. The principles are similar to sonar used by boats and submarines.

The ultrasound image is immediately visible on a nearby screen that looks much like a computer or television monitor. The image is created based on the amplitude (strength), frequency and time it takes for the sound signal to return from the patient to the transducer.

How does the procedure work?

Using imaging guidance, the physician inserts the needle through the skin, advances it into the lesion.

Tissue samples will then be removed using one of two methods.

• In a fine needle aspiration, a fine gauge needle and a syringe withdraw fluid or clusters of cells.
• In a core needle biopsy, the automated mechanism is activated, moving the needle forward and filling the needle trough, or shallow receptacle, with ‘cores’ of breast tissue. The outer sheath instantly moves forward to cut the tissue and keep it in the trough. This process is repeated three to six times.

How is it performed?

Imaging-guided, minimally invasive procedures such as needle biopsy are most often performed by a specially trained interventional radiologist.

Needle biopsies are usually done on an outpatient basis.

A nurse or technologist will insert an intravenous (IV) line into a vein in your hand or arm so that sedation or relaxation medication may be given intravenously during the procedure. You may be also given a mild sedative prior to the biopsy.

A local anesthesia will be injected to numb the path of the needle.

If the procedure is being performed with fluoroscopy, you will sit facing forward for the procedure.

If the procedure is performed with CT, you will lie down during the procedure. A limited CT scan will be performed to confirm the location of the nodule and the safest approach. Once the location of the nodule is confirmed, the entry site is marked on the skin. The skin around the insertion site will be scrubbed and disinfected, and a clean and sterile drape will be applied.

For nodules that are small and deep within the lung, or located near blood vessels, airways or nerves, CT allows better planning of the needle path for a safe biopsy.

CT-guided biopsies require patients to be able to hold still on the CT table for up to 30 minutes. Fluoroscopy and ultrasound allow real-time monitoring of the needle and are often easier for patients who have difficulty holding their breath.

A very small nick is made in the skin at the site where the biopsy needle is to be inserted.

Using imaging guidance, the physician will insert the needle through the skin, advance it to the site of the nodule and remove samples of tissue. Several specimens may be needed for complete analysis.

After the sampling, the needle will be removed.

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.

You will be taken to an observation area for several hours. X-ray(s) or other imaging tests may be performed to monitor for complications.

This procedure is usually completed within one hour.

What will I experience during the procedure?

First, the interventional radiologist will use some form of imaging (such as X-ray, CT, ultrasound, or mammography) to determine the best site for the biopsy. Next, a member of the interventional radiology team will wash the area where the needle biopsy is going to be performed and put local anesthetic in the skin and deeper tissues to numb the area.

Occasionally, an intravenous line will be started, so you can receive fluids and medicines during your biopsy. The interventional radiologist will then use X-ray or other imaging to guide a small needle into the mass or lump. You may feel some pressure during the procedure. The radiologist will use the biopsy needle to remove a tiny piece of tissue or some cells from the abnormal area. The tissue sample is sent to a doctor called a pathologist, who will examine it under a microscope. Usually, the results of the biopsy are ready in two to three days.

What happens after the biopsy? Can I go home?
After your biopsy, you will be asked to stay in the radiology department for a brief time so the staff can make sure you are all right. Most people go home between one and four hours after their biopsy. Keep physical activity to a minimum for the remainder of the day after your biopsy. The biopsy area may be tender or sore for one to two days.

Who interprets the results and how do I get them?

A pathologist examines the removed specimen and makes a final diagnosis so that treatment planning can begin. Depending on the facility, the radiologist or your referring physician will disclose the results to you.

What are the benefits vs. risks?

Benefits

• Needle biopsies often can answer questions about your health without this surgery.
• With image guidance, the abnormality can be biopsied while important nearby structures such as blood vessels and vital organs can be seen and avoided.
• The patient is spared the pain, scarring and complications associated with open surgery.
• Recovery times are usually shorter and patients can more quickly resume normal activities.

Risks
A needle biopsy has few risks because such a small needle is used. Complications are very infrequent; fewer than 1 percent of patients develop bleeding or infection. In about 90 percent of patients, needle biopsy provides enough information for the pathologist to determine the cause of the abnormality. Occasionally, you may be asked to return for a second needle biopsy, or a surgeon may need to do an operation to get the tissue sample. Because everyone is different, there may be risks associated with your needle biopsy that are not mentioned here. The exact risks will be discussed with you in more detail by a member of the interventional radiology team before your procedure begins.
 

• 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.
• Coughing up blood (hemoptysis) is also a risk.
  

What are the limitations of a Needle Biopsy?

In a small number of cases, the tissue obtained during a biopsy may not be adequate for diagnosis.

Needle biopsy is not cost-effective for small lesions one to two millimeters in diameter. Nodules this small cannot provide enough tissue for an accurate diagnosis and are also too difficult to target with a needle.

For patients with certain conditions associated with emphysema, lung cysts, blood coagulation disorder of any type, insufficient blood oxygenation, pulmonary hypertension, and certain heart failure conditions, a needle biopsy may not be recommended. Alternatives to lung biopsy usually include continued follow-up with imaging and surgical removal of the abnormality.