Doctors use a number of tests to diagnose cancer—including blood tests, physical examination, and imaging studies such as X-ray, CT, MRI, and ultrasound. Most cancer diagnoses also require a biopsy, a sample of tissue from the abnormality, which is examined by a pathologist who can determine whether it is cancer, what type of cancer, and whether it’s likely to be fast- or slow-growing. This information is key in deciding the best type of treatment.
While doctors sometimes perform open surgery to obtain a tissue sample, in most cases we can obtain samples using an interventional radiology technique. During an interventional needle biopsy we use a moving X-ray (fluoroscopy), CT, ultrasound, or MRI to guide a small needle into the abnormal area, then remove a tissue sample for the pathologist’s analysis.
Depending on the sample size needed the doctor will either use large core needle biopsy—a technique using a special needle that obtains a larger biopsy sample—or fine needle aspiration to withdraw cells from a suspected cancer and diagnose fluids that have collected in the body. Our interventional radiologists use the latest technologies to obtain adequate tissue in a safe and comfortable manner.
How do I get ready for the biopsy?
If you are undergoing ultrasound guided or stereotactic (X-ray guided) biopsy no special preparation is needed. Leave your jewelry and other metal accessories at home if you will be undergoing an MRI guided biopsy, as these can interfere with the magnet in the MRI scanner.
What will happen during the procedure?
During an image-guided biopsy we will inject a local anesthetic into the area to be biopsied. Once the area is numb we will image the area, then use the images to guide the device—a fine needle, core (hollow) needle, or vacuum device—directly to the site. We will take one or more samples of tissue while viewing the abnormality and needle in real time on a monitor.
During an MRI guided biopsy you will lie on a moveable exam table. We will insert an intravenous (IV) line into a vein in your hand or arm and will give you a contrast agent (dye) called gadolinium through this line. Using computer software, we will measure the position of the abnormality and calculate the correct position and depth of the needle placement. We will numb the area around the abnormality with a local anesthetic, insert the biopsy needle, advance it to the abnormality, verify its position using MRI, then remove some tissue samples from the area.
An image guided biopsy procedure takes from about 30 minutes to an hour.
Are there any risks?
Needle biopsy is typically an outpatient procedure with very infrequent complications; less than one percent of patients develop bleeding or infection.
After the test
After a biopsy most people are able to return to their normal routine within 24 hours. A pathologist will examine your tissue sample and make a final diagnosis. It may take a few days before the final tissue analysis (pathology report) is ready. If your biopsy results are negative, meaning we determine that the abnormal tissue is not cancerous, we will let you know immediately, and we will let you know if any follow up is necessary. If your biopsy results are positive, meaning we determine that the abnormal tissue is cancerous, we will help you understand the results and talk with you about the next steps in the process.