PET/CT in cancer diagnosis and treatment

PET scans can be combined with CT scans at many cancer centers to provide more detailed images to help detect cancer and determine its stage.

PET/CT scan helps in staging the disease. A cancer stage is a classification based on a description of where the tumor is, how far it has spread, and how it changes how organs in the body work. Knowing the stage of the disease helps you and your doctor choose the best treatment. It also helps doctors predict your chances of recovery.
Doctors also use PET-CT scans to:
Find the right tumor site for biopsy. Find out the response to cancer treatment Assess the patient's response to treatment Plan radiation therapy

CT and PET scans have different clinical implications. CT scans provide detailed images of tissues and organs inside the body. PET scans help detect abnormal activity. Therefore, taking these two approaches together can help provide more detailed information about the cancer.

PET creates images of organs and tissues in the body. First, the technician will inject a small amount of radioactive material into your body. Your organs and tissues absorb this substance. Sites that use more energy absorb more radioactive material. Cancer cells absorb a lot, because they need to use more energy than healthy cells.
CT provides images of the inside of the body using X-rays taken from different angles. The computer combines these images to create detailed three-dimensional images that help detect abnormalities, including tumors. Sometimes, contrast material is introduced into the body before the scan to provide more detailed images.

PET, CT, and PET/CT scans are all harmful. The biggest harm is radiation exposure. Radiation exposure from a PET-CT scan is similar to a full-body CT scan done in the presence of contrast. CT scans that are limited to one area of ​​the body or done without contrast give patients less radiation exposure.
The benefits of these tests often outweigh the harms. You may still have multiple CT scans or other tests with radioactive material. Tell your doctor about your previous scans. If you're concerned, ask your doctor to recommend a lower dose of radiation.

When you schedule a PET/CT scan, the staff will guide you in preparation before the scan. For example, you may need to drink water after midnight the night before your scan. Or you may need to stop eating and drinking at least 4 hours before the scan. For some scans, you may not need to stop eating and drinking. Therefore, you should tell your healthcare provider if you have diabetes.
You should also talk about all medications you are taking. Ask if you can take your medicine on the day of the scan. In addition, you should also let your doctor know about allergies and other medical conditions. If you are breastfeeding or pregnant, tell your doctor. PET scans can be dangerous for the baby.
Staff will ask you to sign a PET-CT risk acceptance form. If you are concerned, ask your doctor before signing.

You may need to put on a hospital gown or remove interfering clothing or jewelry. The technician or nurse will inject the medicine into a vein. Then, the radioactive material is given into a vein. You will not feel anything from the radioactive material.
This substance takes 30 to 90 minutes to reach the tissues to be scanned. You need to lie still without moving or talking. Moving too much can cause radioactive material to get into organs or tissues that aren't being imaged, making it more difficult to read results.
During the test, the technician will help you lie on a padded table. The table can have pillows, straps or a cradle to support your head. The most common position is lying on your back, but you can also lie on your side or on your stomach. Your location depends on where your doctor wants to scan.
If PET/CT is used to plan radiation therapy, you may wear a mask or cast during the scan.

You may be given an injection of contrast material during a CT scan. Medicines can be given by mouth, by infusion or intravenously. Contrast makes the image more detailed.
Contrast injected into a vein may make you feel hot or itchy. You may feel metal in your mouth, but these sensations should go away in a few minutes. If you have a more serious reaction such as difficulty breathing, tell the technician right away.

PET/CT does not harm your body, but you need to lie still for the entire scan. The technician may ask you to rest your arms above your head and hold your breath during the capture to limit image noise.
The technician can raise, lower or tilt the table during the scan. This helps to recognize images from different angles. You may also hear a hissing or clicking sound from the machine.
The process of waiting for the drug to be absorbed into the body can take about an hour. The scan only takes about 30 minutes. If the scanner scans a large part of the body, the test may take longer. The technician can tell you about the scan time.

You can perform normal activities after shooting including driving. Your healthcare provider will advise you to drink several glasses of water. This helps wash the radioactive material and contrast out of your body.
Vinmec International General Hospital is equipped with the US PET/CT GE Discovery MIDR system with 128-strip CT - one of the most advanced PET/CT systems in the world. The advantage of this system allows displaying images with high resolution, while significantly reducing radiation dose for patients.
Since being put into use until now, Vinmec International General Hospital has performed thousands of PET/CT scans to help diagnose, stage the disease and monitor the response to treatment for almost all types of patients. Cancers such as lung, liver, stomach, breast, bone, lymph node cancers... PET/CT has become an effective and indispensable assistant, the "key to solve problems" of doctors every day. cancer.

Reference source: cancer.net
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