When you’re being treated for cancer, you want to know how well your therapy is working. Imaging tests like CT scans and PET scans can help.
With these tools, your health care providers can get a clear picture of what’s happening inside your body. They can use this information to monitor your progress and adjust your treatment plan if needed.
How imaging tests monitor cancer treatment
Health care providers use imaging tests for cancer treatment to track how your cancer is responding to therapy. These tests can:
- Show whether a tumor is shrinking, staying the same size or growing
- Spot if cancer has spread to other parts of your body
- Help you and your care team decide if you need to adjust your treatment
“CT scans and PET scans are used for treatment planning, response to treatment and surveillance,” said Caitlyn Harrison, MD, a radiologist with Banner MD Anderson Cancer Center.
Regular cancer treatment monitoring helps make sure you’re getting the most effective care possible.
What is a computed tomography (CT) scan?
A CT scan for cancer uses X-rays to create detailed, cross-section images of structures inside of your body. “We can see all the organs,” Dr. Harrison said. These scans are often used to monitor lung, liver and colon cancer.
They can:
- Spot tumors and track changes over time
- Measure the tumor size before, during and after treatment
- See whether cancer has spread to other organs
- Detect complications like infections or blockages
What is a positron emission tomography (PET) scan?
A PET scan for cancer works differently. It shows you how your tissues and organs are functioning. With a PET scan, a small amount of a radioactive substance is injected into your body. These scans are used for many types of cancer, such as lymphoma, breast cancer and lung cancer.
They can:
- Highlight areas where cancer may be growing
- Show if cancer cells are still active after treatment
- Spot cancer that might not be visible on a CT scan
- Show whether cancer has spread or returned
CT vs. PET scans: Which one is right for you?
Both CT and PET scans are important cancer imaging tests but they provide different types of information:
- CT scans focus on the structure of tumors. They can be used to help plan surgery. “We can get a better idea of whether a tumor is touching something like a blood vessel,” Dr. Harrison said.
- PET scans show metabolic activity (the activity in your body’s cells). They can detect cancer cells that a CT scan might miss. “We sometimes see small things on a PET scan that might look normal on other imaging,” Dr. Harrison said.
Your health care provider will recommend the scan that best fits your cancer type and treatment plan. In some cases, they may combine both or alternate between the two.
What to expect during a CT or PET scan
If your health care provider orders a CT or PET scan, here’s what you can expect:
- CT scans are quick and painless, though you might need a contrast dye to make it easier for your care team to see certain things. Once you get the contrast dye you can be scanned right away and the scan itself only takes seconds.
- PET scans take longer because the injected tracer needs time to circulate through your body. “For most PET scans, after you get injected with the tracer, you have to wait an hour for the uptake in your body. Then the scan takes about 20 minutes,” Dr. Harrison said.
For both types of scans, you need to lie still while the machine takes the images. Your care team will explain any specific instructions, like if you need to fast before your test.
When should you talk to your health care provider about imaging tests?
Imaging tests are usually scheduled at key points during your cancer treatment. Your health care provider will explain when imaging might be helpful.
You might want to discuss your imaging timeframe with your provider if you:
- Have new symptoms or symptoms that are getting worse
- Are worried about whether your treatment is working
- Want to better understand how imaging fits into your care plan
How to access imaging tests for cancer treatment
If you need imaging tests, your care team will guide you through the process to make sure everything goes smoothly.
- Your provider will let you know if and when you need imaging tests.
- Many insurance plans cover these tests, but it’s a good idea to check your plan’s coverage.
- Hospitals and outpatient imaging centers often perform imaging tests.
What’s next for cancer imaging?
Advancements in technology are improving cancer treatment monitoring. Developments include:
- New PET tracers to identify different types of cancer.
- Theranostics, or a combination of therapy and diagnostics. If a tumor is diagnosed as a certain type, it can be treated with a precisely targeted therapy.
- Liquid biopsies, a type of biopsy that relies on blood samples instead of tissue to detect, monitor or help guide cancer treatment.
- Improvements in other imaging tests, like MRIs, to see soft tissues better.
- Artificial intelligence (AI) to analyze scans faster and more accurately.
These technologies are helping health care providers diagnose cancer earlier and create more personalized treatment plans.
The bottom line: Imaging tests are key to effective cancer care
CT scans and PET scans are valuable tools for tracking your progress. These imaging tests for cancer treatment help your provider adjust your care plan and get important insights.
If you’re being treated for cancer and you have questions about imaging, reach out to your health care provider or an expert at Banner Health.
