HPV Cancer Resources

There are five general types of “scans” that may be used in diagnosing your cancer.

These are technologies that were developed to let doctors look inside the human body without cutting into it. Your doctor will choose which of these procedures is the most appropriate based on a number of criteria. Because each person’s treatment path and ultimate prognosis are often tied to the results of the various scans, many cancer patients develop “scanxiety” (i.e. scan anxiety) either during their scans, or while awaiting the results.

These days many scans (and other medical test results) are sent directly to the patient via a patient portal as soon as they become available. My advice is to NOT look at your scan results in advance of going over them with your doctor. That’s because the descriptions often cannot be correctly interpreted without medical knowledge, and it’s easy for a patient to think that a particular phrase suggests something bad when it fact it does not. You’ll have to wait to discuss treatment options (based on the scan results) with your doctor until you meet in person, so I suggest going over the scan at the same time. Posting these tests results in patient portals takes place because the US Congress ordered Health and Human Services to provide this info via a 2016 law, the 21st Century Cures Act. The goal of the regulations was to promote health data-sharing and patient access. You can find out more details if interested in this article The fight over how to deliver bad news to patients.

Here are some basic descriptions of the scans you might encounter, but these techniques can be used in different ways depending on circumstances:

X-rays: An x-ray involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging. They are relatively inexpensive. Often used to visualize injuries to arms and legs.

Ultrasound: Ultrasound imaging (also called sonograms or sonography or ultrasound scanning) uses high-frequency sound waves to obtain images from inside the human body. Unlike x-ray radiography or CT scanning, there is no ionizing radiation exposure with sonography. It’s good for visualizing fluid filled cavities such as the womb (hence its use in pregnant women to see the developing fetus), the heart, and the gallbladder.

MRI: Magnetic resonance imaging (MRI) is an exam that uses a strong magnet to take pictures of internal organs and tissues. There is no ionizing radiation, as with X-rays or CT scans. The level of detail with MRI is extraordinary compared to any other imaging technique. However, it does not do a good job at seeing inside air filled cavities, such as the lungs. It is expensive and time consuming. Some people don’t like to get MRI exams because they get claustrophobic inside the MRI machine.

CT scan: A computed tomography (CT or CAT) scan allows doctors to see inside your body. It shows more detail than a regular X-ray. CT scanners use a narrow X-ray beam that circles around one part of your body. This provides a series of images from many different angles. A computer uses this information to create a cross-sectional picture. Like one piece in a loaf of bread, this two-dimensional (2D) scan shows a “slice” of the inside of your body. This process is repeated to produce a number of slices. The computer stacks these scans one on top of the other to create a three-dimensional (3D) image. This can give your doctor a better view of your organs, bones, or blood vessels. The dosage of X-rays from a CT scan is much, much greater than from a single X-ray. It can give 70 to 200 times as much radiation as a chest X-ray. It is also significantly more expensive than an X-ray.

PET scan: A positron emission tomography (PET) scan is an imaging test that uses a special dye containing radioactive tracers. These tracers are either swallowed, inhaled, or injected into a vein in your arm depending on what part of the body is being examined. Certain organs and tissues then absorb the tracer. The tracer will collect in areas of higher chemical activity, which is helpful because certain tissues of the body, and certain diseases, have a higher level of chemical activity. These areas of disease will show up as bright spots on the PET scan. Today, almost all PET scans are performed on instruments that are combined PET and CT scanners. The combined PET/CT scans provide images that pinpoint the anatomic location of abnormal metabolic activity within the body. The combined scans have been shown to provide more accurate diagnoses than the two scans performed separately. PET scans are also very expensive.

Note: PET scans are often done as part of the initial workup of newly diagnosed HPV+ head and neck cancer patients, where they can show how far the disease has spread. However, they have also been done as part of follow up surveillance for patients post-treatment. A study was done to determine if this was equally valuable: Corpman, D.W. et al Posttreatment surveillance PET/CT for HPV‐associated oropharyngeal cancer. Head and Neck 41, 2, 456-462 (2019). Here are the results: “Surveillance PET/CT demonstrated 100% negative predictive value and sensitivity, 59.9% specificity, and 13.4% positive predictive value. Surveillance PET/CT led to 90 imaging studies and 31 biopsies; 91.1% and 77.4% were negative for recurrence, respectively. Surveillance PET/CT led to meaningful salvage therapy in 1.6% of cases. PET/CT‐detected recurrences did not have improved survival compared to clinically detected recurrences.” Their overall conclusion: “For HPV+OPSCC patients, surveillance PET/CTs frequently lead to unnecessary testing and rarely to meaningful disease salvage. They have no demonstrated survival benefit and should be interpreted cautiously to prevent patient harm.”

In simple terms, PET scans rarely find any cancer recurrences, and as a result, many places have eliminated them once patients have gotten past the first couple of years. Recurrences are usually found by the patients themselves as they develop symptoms, at which point they contact their doctors.