Stereotactic or Stereotaxic Biopsy

General Description

A stereotactic biopsy, also called a stereotaxic biopsy, is a procedure in which tissue samples are taken with the assistance of three-dimensional imaging for subsequent laboratory analysis. Typically, magnetic resonance imaging (MRI), computed tomography (CT), or mammography is used to obtain a clearer view of the area to be examined.

This procedure is minimally invasive and rarely requires hospitalization, allowing patients to return to their normal routine in a short time.

When Is It Indicated?

A stereotactic biopsy is used to analyze abnormal formations in the following organs:

• Breasts: Used when masses or calcifications are detected that cannot be clearly seen through diagnostic imaging tests. It allows for the detection of breast cancer or benign cysts.
• Brain: Indicated when the lesion is located in a deep area of the brain or near vital structures. The procedure diagnoses malignant tumors or brain infections.
• Lungs: It is the standard procedure when a mass is detected but is not clearly visible on imaging, as the lung is not an organ where a lump can be palpated. It is useful for diagnosing lung cancer, benign cysts, or infections.
• Liver: Performed when the mass is in a difficult-to-access location. It is suitable for evaluating liver disease or detecting cancerous tumors.

How Is It Performed?

Stereotactic biopsies are usually performed under local anesthesia, although some cases require general anesthesia.

• Breast stereotactic biopsy: The patient lies face down, positioning the breast into an opening where it remains suspended. The examination table is slightly elevated to facilitate positioning of the breast between the two plates of the mammography device. After injecting anesthesia, a small incision is made, through which a needle or cannula is inserted to collect tissue samples.
• Brain stereotactic biopsy: The patient is positioned face up on the examination table under general anesthesia. While MRI or CT images are obtained, the specialist makes an incision in the scalp and then drills a small hole in the skull (about 18 millimeters in diameter) to insert the needle and extract the sample.
• Liver or lung stereotactic biopsy: The patient's position depends on the area to be biopsied. First, the skin is exposed and disinfected, then local anesthesia is applied. Guided by MRI or CT images, the specialist inserts a cannula or needle to obtain a tissue sample.

If a needle is used, pressure is applied to the area to prevent bruising or bleeding. If an incision is made, it is closed with sutures, which, once removed, leave minimal scarring.

The obtained samples are sent to the laboratory for analysis. They must be preserved in formaldehyde (CH₂O) to prevent decomposition and sealed to avoid oxidation. Pathologists section them into thin slices, apply stains that help visualize cellular characteristics, and place them on glass slides for microscopic examination.

Risks

Stereotactic biopsies do not pose a high risk to the patient's health, although this depends on the area in which they are performed.

Procedures in the breast, lung, or liver may cause inflammation, bruising, or bleeding at the puncture site in the days following the biopsy. Moderate pain may be felt at the incision site.

Brain biopsies carry a higher risk due to the sensitivity of the organ. In addition to potential bleeding at the needle insertion site, seizures, mild headaches, or coma may occur. There is also a small risk of death following the procedure.

What to Expect from a Stereotactic Biopsy

Before undergoing a stereotactic biopsy, the patient must sign an informed consent form.

On the day of the breast, liver, or lung biopsy, the patient must wear the gown provided by the medical center and position themselves on the examination table to allow easy access to the organ being examined. When the procedure begins, the anesthesia injection causes a slight pinch but prevents pain. Once completed, a bandage is applied to compress the incision site to prevent bruising and swelling. This bandage can be removed after a few days, during which intense physical exercise should be avoided. A pain reliever can be taken to alleviate discomfort, which should be reported to the specialist if it worsens.

For brain biopsies, general anesthesia is used, so the patient remains unconscious during the procedure. After the intervention, they will remain in the recovery unit for observation for several hours. In these cases, hospitalization is usually necessary to continuously monitor progress. Incision pain may be intense, so analgesics are provided. If no neurological alterations are observed, the patient may return home and rest. It is recommended to avoid exertion, driving, flying, or consuming alcohol and nicotine. Additionally, patients should try to walk for about 10 minutes a day, sleep with their head slightly elevated, drink plenty of water, and eat fiber-rich foods. The duration of medical leave varies depending on the patient's recovery progress.

Stereotactic biopsies take between 20 and 45 minutes to perform.

Results are explained to the patient during a follow-up consultation between five and seven days after the sample collection.

Medical Specialties That Request a Stereotactic Biopsy

Oncologists, gynecologists, neurologists, pulmonologists, and gastroenterology specialists commonly request tissue samples through this type of image-guided biopsy. Pathologists analyze the tissue and prepare the final report.