Oral Cancer: Tests After Diagnosis

After a diagnosis of oral cancer, you will likely need more tests. These tests help your healthcare providers learn more about the cancer. They can help show if it has grown into nearby tissues or spread to other parts of the body. The test results help your healthcare providers work with you to decide the best ways to treat the cancer. If you have any questions about these or other tests, talk with your healthcare team.

Some of the tests used after diagnosis include: 

  • CT scan

  • MRI

  • PET scan

  • Ultrasound

  • Barium swallow

  • Panorex films

  • Chest X-ray

You can learn more about each of these tests below.

CT scan

This test uses a series of X-rays and a computer to make detailed images of your insides. A CT scan is much more detailed than a regular X-ray. Scans of your head and neck might be done to look for tumors in your mouth, lymph nodes, or elsewhere. A scan of your entire lower jawbone (mandible) might also be done.

During the test, you lie still on a table as it slides through the center of the CT scanner. Then the scanner sends a beam of X-rays at your body. A computer uses the X-rays to create many pictures of the inside of your body. These are put together to create a 3-D picture. You may be asked to hold your breath once or more during the scan. You may be asked to drink a contrast dye after the first set of pictures is taken. This dye can help get clearer images. It will pass out of your body over the next day or so through your bowel movements. If the dye is put into your blood through an IV in your arm, it may cause a feeling of warmth in your body for a few minutes. In rare cases, it can also cause hives or other allergic reactions. Tell the technician if you don’t feel well during the test.


This test uses magnets and radio waves to make detailed pictures of the inside of your body. It’s a lot like a CT scan, but it doesn’t use X-rays. An MRI may be used to look for cancer that's spread to your neck.

For this test, you lie still on a table as it moves into a narrow, tube-like scanner. The scanner sends beams of radio waves at the part of your body being scanned. A computer uses the radio waves to create a 3-D picture of your insides. You may need more than one set of images. Each one may take 2 to 15 minutes, so that the whole scan may take an hour or more. A contrast dye might be put into a vein in your hand or arm before this scan. It helps get even clearer images of the inside of your body. You might be given earplugs because there are loud thumping and buzzing noises during the scan. If you're claustrophobic, you may need to be given a sedative before having this test.

PET scan

A PET scan is used to find cancer cells anywhere in your body. A needle is used to put a radioactive sugar into your blood through a vein. The sugar travels through your body in your blood and is taken up by the cancer cells. Cancer cells are more active and use the sugar faster than other cells, so the radioactivity will collect in them. Then a machine takes pictures of your whole body. The places where the solution collects show up as "hot spots" on the scan. Some people are sensitive to the radioactive glucose and may have nausea, headache, or vomiting.

A PET scan is often combined with a CT scan (PET-CT scan). This allows areas that show up on the PET scan to be compared to the more detailed images of the CT scan. This test is very good for looking for cancer that has spread from where it first started.


This test uses sound waves to make images of the inside of your body. A wand-like transducer is moved over your skin to show pictures on a computer screen. Ultrasound may be used to look for swollen lymph nodes in your neck. This may be a sign that cancer has spread to those nodes.

Barium swallow

This test is a series of X-rays done while you swallow a thick, chalky liquid that contains barium. This liquid shows up on X-rays. Your healthcare provider may use this test to see if there's cancer in your esophagus. This is the tube that connects your mouth to your stomach. It also shows how well you swallow and if the cancer is causing problems with normal swallowing.

Panorex films

This test uses X-rays to take a picture of your upper and lower jawbones. It can show if cancer has spread to these bones. You sit or stand and place your chin on a rest, looking straight ahead. The X-ray machine moves around your head, taking the pictures.

Chest X-ray

A chest X-ray can help show if cancer has spread to your lungs. For the test, you stand in front of a rectangular target area where the X-ray film is held. You may be asked to hold your arms to the side or over your head. You take a breath and stay still for a few seconds. An X-ray will be done from the front and from the side.

Working with your healthcare provider

Your healthcare provider will talk with you about which tests you'll have. Get ready for the tests as instructed. Be sure you know what the test will be like and why it's being done. Ask questions and talk about any concerns you have.

Online Medical Reviewer: Amy Finke RN BSN
Online Medical Reviewer: Jessica Gotwals RN BSN MPH
Online Medical Reviewer: Todd Gersten MD
Date Last Reviewed: 7/1/2023
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