Computed tomography (CT)-guided biopsy
Computed tomography (CT)-guided biopsy is a diagnostic procedure that involves the use of CT imaging to help accurately position a thin needle to extract tissue or fluid from a mass located in internal organs or deep tissues. This method is particularly valuable for patients who may not tolerate traditional surgical biopsies, offering a less invasive alternative. It is commonly used to diagnose various types of cancers by examining solid tumors in organs such as the lungs, liver, kidneys, bones, and adrenal glands. The process typically involves patient preparation, including potential sedation, and careful monitoring during the procedure, which can take approximately twenty minutes.
During the biopsy, the physician first performs a CT scan to identify the target site, followed by the insertion of the needle to collect the sample. Post-procedure monitoring is essential to check for any complications, although risks such as bleeding or infection are generally minimal. The collected samples are then sent to a pathologist for analysis to determine the nature of the mass, which is crucial for informing subsequent treatment plans. Overall, CT-guided biopsies are considered an effective tool in oncology for achieving definitive diagnoses and tailoring appropriate therapies.
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Computed tomography (CT)-guided biopsy
DEFINITION: A biopsy is needed when a mass has been found on physical examination or from an X-ray, magnetic resonance image (MRI), or CT scan. In a CT-guided biopsy, a very thin needle is inserted into the mass while it is being visualized with the CT to withdraw fluid or tissue to be used to determine a diagnosis. CT-guided biopsy can allow a patient to avoid having to go to an operating room to have the biopsy completed. Many oncology patients are unable to tolerate an operation, so this procedure is a valuable diagnostic tool.
Cancers diagnosed: CT-guided biopsy can be used to help diagnose many different masses located in various organs in the body, such as the lung, liver, kidney, bones, and adrenal glands. Solid tumors are frequently biopsied to determine the type of tumor and how fast it is growing. This information will then be used by the oncologist to determine what type of chemotherapy to use and whether radiation would benefit the patient.
Why performed: A biopsy is done to achieve a definitive diagnosis for tumors and masses. In order to ensure that proper treatment is given to the patient, the exact type of cancer must be determined. A mass in the kidney may be kidney cancer or another type of cancer that has spread to that organ. The biopsy can determine what type of cells are present and then what type of therapy would be best to treat that diagnosis. A CT-guided biopsy is done on masses located on internal organs or in deep tissue. Often these masses cannot be felt on examination but are found through imaging.
Patient preparation: This procedure can be done on both an inpatient and an outpatient basis. Preparation will depend on in what organ or area the mass is located. The patient may receive a sedative or pain medication before the procedure. They may also be connected to a cardiac monitor to ensure that no cardiac abnormalities occur. The patient may be asked not to eat anything in the eight hours before the procedure. It is important to identify patients who have claustrophobia, as they may experience anxiety with the CT itself and need medication to decrease this anxiety. Patients may have their blood levels monitored to ensure that they have the ability to clot after a biopsy has been completed. Patients should give informed consent prior to having the biopsy done.
Steps of the procedure: The procedure can take as little as twenty minutes to complete. The patient is positioned as comfortably as possible on the back, side, or abdomen to allow for proper access to the area requiring biopsy. The patient should remain in the same position during the whole procedure. A preliminary CT scan is performed to locate the site for needle insertion for the biopsy. Once this site is determined, the skin is properly cleaned and a numbing medication is injected. The biopsy needle is then inserted through the skin into the mass. Another CT is done to determine where the tip of the needle is resting. When the tip of the needle is in the correct location, then the biopsy, or sample, is taken and prepared for pathology. After the needle is removed, an additional CT is done to ensure that there are no air bubbles or bleeding.
After the procedure: After completion of the procedure, the patient is monitored either in the hospital or the recovery room for a few hours and then discharged home. The patient may still be drowsy or dizzy from the medication and is typically advised not to drive.
Risks: CT-guided biopsies are not recommended for patients who have a bleeding disorder or thrombocytopenia. If the patient is or may be pregnant, then special precautions will need to be taken. Risks related to CT-guided biopsies are minimal and include bleeding and infections. It is not recommended that a needle biopsy be done on the spleen because of the tendency of that organ to bleed. There is also a 25 percent risk of a pneumothorax, or collapsed lung, when a biopsy of the lung has been done. Pneumothorax may also occur when biopsies of the liver or adrenal glands have been done.
Results: A preliminary evaluation may be done by the physician prior to sending the sample to pathology. Not all physicians may do so. Many times, the sample is sent straight to the pathologist for diagnosis and evaluation. The pathologist will be able to determine what the mass consists of and give a diagnosis so that treatment may begin. If the sample size was not sufficient or the pathologist is unable to determine a diagnosis, then a repeat biopsy may be necessary.
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