This allows the PET scan to show where the sugar metabolizes in your body so your doctors can see if your cancer is growing. The radiotracer does not cause any side effects or pain.
PET scans are very safe. There are no side effects associated with the radioactive tracers, which only remain in your body for a short time. In addition, the dose of radiation is very small — similar to several years' worth of natural radiation from the environment. Allergic reactions are very rare and usually minor.
After your PET scan, you can go on with your normal activities straight away. The injection of the radioactive material does not make you feel any different or drowsy. There are no sedative drugs or anaesthesia used during this procedure. Your scan results will not be available immediately.
If undergoing a combination PET-CT scan, the iodine-based contrast dye used for the CT component can cause side effects, including nausea, vomiting, headache, itching, flushing, and mild rash. In rare cases, a serious, all-body allergic reaction known as anaphylaxis may occur.
With a PET or a PET/CT scan, you will give off very low levels of radiation for around 6 hours afterwards. As a precaution, you should avoid being close to women who are pregnant during this time. It should also be safe to be around adult pets, as long as they are not pregnant.
After the test: Drink lots of fluids for the next 24 hours to help flush the tracer out of your body. Most of the tracer will be flushed from your body within 6 to 24 hours. Allergic reactions to the tracer are very rare.
18F-Fluorodeoxy glucose positron emission tomography‒computed tomography (18F-FDG-PET) can detect malignant lymph nodes of even normal size, thus overcoming one of the major limitations of CT.
Drinking plenty of fluid after the scan can help flush it from your body. As a precaution, you may be advised to avoid prolonged close contact with pregnant women, babies or young children for a few hours after a PET scan, as you will be slightly radioactive during this time.
The radioactive tracer gives off very small levels of radiation that go away very quickly. As a precaution, you should avoid close contact with pregnant women, babies and young children for 6 hours after the scan. You need someone to take you home and stay overnight if you've had medicine to help you relax (sedative).
As a precaution, you may be advised to avoid close contact with pregnant women, babies and young children for a few hours after having a PET scan. This is because you'll be slightly radioactive during this time.
You can do normal activities after the scan. This includes driving. The staff will tell you to drink several glasses of water. This helps wash the radioactive substance and dye out of your body.
After a PET-CT scan
Drink lots of water. It helps wash any leftover radioactive substance and dye out of your body. The scan results will be interpreted by the nuclear medicine physician and/or a radiologist, and that report will be sent to your doctor.
PET scanning can give false results if chemical balances within the body are not normal. Specifically, test results of diabetic patients or patients who have eaten within a few hours prior to the examination can be adversely affected because of altered blood sugar or blood insulin levels.
Preparation for the Procedure
You will be asked to follow the Limited Carbohydrate diet for the previous 24 hours before the date of your appointment. Do not eat or drink anything, except water, for 6 hours before the exam. You may drink water, as much water as you can would be helpful, until arrival.
Normal muscles accumulate little FDG, but muscles exercised just before or around the time of the scanning can exhibit intense uptake into those muscles—for example, possibly mimicking cancer, he added.
If you're pregnant, don't cuddle with your child for at least 24 hours after the scan. Also, your child should avoid direct contact with infants and toddlers until the next day.
Do I have to pay for a PET scan? There is no cost for most PET scans if you are a citizen or permanent resident of Australia and covered by Medicare. For a limited number of indications that are not approved by Medicare, there can be a charge to the patient.
This type of scan help determine whether a smaller spot is cancerous or benign, as cancerous lesions are much more likely to light up on a PET scan than benign spots or scar tissue.
Not all cancers show up on a PET scan. PET scan results are often used with other imaging and lab test results. Other tests are often needed to find out whether an area that collected a lot of radioactive material is non-cancerous (benign) or cancerous (malignant).
Your PET/CT technologist will prepare your images for the radiologist, who will then forward the results to your physician within 24-48 hours after the procedure. Your doctor will then meet with you to discuss the results and answer any questions you may have.
Temporary side effects – The iodine-based contrast dye used in a PET CT scan can cause temporary side effects. Some PET scan side effects are diarrhea, nausea, etc., which eventually fade within a day.
In general, PET scans may be used to evaluate organs and/or tissues for the presence of disease or other conditions. PET may also be used to evaluate the function of organs, such as the heart or brain. The most common use of PET is in the detection of cancer and the evaluation of cancer treatment.
Tissue that has a high rate of metabolism and a high consumption of sugar appears as especially dark spots on black-and-white PET images, and on color images as especially bright spots.
However, PET scans are more accurate in detecting larger and more aggressive tumors than they are in locating tumors that are smaller than 8 mm a pinky nail (or half of a thumb nail) and/or less aggressive cancers.