The PET/CT procedure consists of merging two methods of medical imaging sequentially to obtain images of the anatomy (during the CT portion of the examination) and of the metabolic activity of the body cells (during the PET portion of the examination).
As preventive tools
As preventive tools, the PET/CT can discover tumors, assess the ferociousness of a cancer, and establish the stage of cancers. Your physician will subsequently use the results obtained to decide on the most appropriate treatment to follow. In 15% of cases, the PET/CT checkup leads to the finding of new metastasis. In such occurrences, the treatment can be customized more closely to the patient’s inherent circumstance.
PET/CT Examination Practice
To perform a PET/CT scan, a glucose-based radioactive substance (FDG-F18) is injected through intravenous route. As body cells used glucose as their main sources of energy, the FDG-18 liquid (a glucose) is used by body cells as a source of energy. However the cancerous cells which have an augmented metabolism will ingest a greater quantity of FDG-F18 than the healthy cells. Only an hour after the inoculation, images are obtained: initially a CT, but immediately followed by PET images. Both sequences of images are then amalgamated to allow a precise localization of FDG-F18 hyper-fixation areas.
In the field of oncology, the PET/CT examination is an extraordinarily efficient technique to acquire information in relation to:
- Classification of indeterminate solitary pulmonary nodules;
- Preoperative staging to estimate distant metastasis of non-small cell lung cancers;
- Staging of colorectal cancers;
- Staging of Hodgkin’s disease and non-Hodgkin lymphomas;
- An evaluation of the existence of metastasis in cases of melanoma;
- An evaluation of the degree of loco-regional recurrence and distant metastasis, as well as of The action response in cases of breast cancer;
- Staging of head and neck cancers, and esophagus cancers;
- Staging of well differentiated thyroid gland cancers characterized by a positive thyroglobulin and negative Iodine-131 scan;
- Differentiation between the recurrence of a brain tumor and radiation necrosis due to previous radiation cure.
Using PET in Neurology
A PET/CT scan can be used for the early analysis of Alzheimer’s malady and the recognition of other types of dementia. Additionally this examination is helpful for the localization of a focus of epilepsy when typical medication does not allow for the suitable control of the malady and when a surgery is considered.
Using PET in Cardiology
In cardiology, a PET/CT examination can be used to assess the myocardial viability, which can then establish if a revascularization could be of beneficial to the patient.
One Day Prior to Your Examination
Pass up intense physical activity and avoid being in cold environment. We recommend that you do not use the air conditioning intensely at your home or in your car. The night before your exam, we recommend patients to take a hot bath
At dinner, take a light meal and avoid eating carbohydrates (such as pasta, bread, rice, potatoes, chips, fruits and pastries). It is also recommended to avoid sugar and its substitutes. Be careful! Various types of food contain sugar (e.g. juice). You can however take a light snack in the evening before the test. Keep in mind that the localization of the radioactive substance (FDG) in your body will depend on your blood sugar level. Hence, it is crucial for the success of your scan to follow these recommendations.
the Exam Day
- You must be in a fasting state (from midnight; 6 hours minimum) and you are only allowed to drink water (as much as you want). You must avoid smoking.
- If you are diabetic, you can take your NPH insulin (long lasting action) but not your R type insulin. You can consult your physician or pharmacist in case of doubt. If you take oral hypoglycemic medication, please communicate with us.
- You can take all of your usual medication with water.
- You must avoid being cold (no air conditioning) and avoid heavy physical activity.
- If you are a woman, you might have to take a pregnancy test (urine sample) to be sure that you are not pregnant.
- If you are breast-feeding your baby, you will have to avoid doing so for 24 hours after your examination.
What you should bring with you for your examination
- When possible, a copy of your last radiological examinations report (CT, MRI, etc.), along with the CD of those examinations.
- Your medical information (for example, the surgeries you have had and all the dates of your chemotherapy).
- A list of all the medication you are taking
If you are claustrophobic, you might want to come on site and see whether or not you believe you will be able to go through with the examination. Please communicate with us to plan a pre-examination visit.
You might have to receive an insulin injection on the morning of the examination. In such a case, this procedure will be done under medical supervision.
FDG is ordered 24 hours in advance specifically for you. If you need to cancel your appointment, please notify us one working day in advance. Otherwise, you will have to assume the cost of the product.
If you are a woman, you might have to take a pregnancy test (urine sample) to be sure that you are not pregnant.
The approximate duration for the entire TEP/CT examination process is three hours and will essentially consists of five steps :
- We will first ask you a few questions in order to collect your medical information. Your blood sugar level will as well be assessed.
- You will have to drink an orange-flavored barium (this is a medium contrast liquid for the digestive system).
- Through intravenous route, we will dispense you a glucose-based radioactive isotope: the FDG. This substance does not have any side effect.
- For about one hour, you will be asked to take a break on a relaxation chair in an unlit room.
- Subsequently, your TEP/CT examination will take place and will last less than one hour.
- Finally and not least, you should be able to resume your usual activities by the time you leave our clinic, with a negligible quantity of radioactivity in your body.