Early detection of cancer with PET/CT
The first diagnosis of cancer, the stage of the cancer and the treatment protocol of the cancer can be determined with PET/CT. It is an imaging test that helps reveal how your tissues and organs are functioning by using radioactive drug (tracer) to show cancers activity. A PET/CT scan can provide a vision to fight effectively against cancer.
Positron Emission Tomography–Computed Tomography (better known as PET/CT) is a medical imaging technique using a device which combines in a single gantry system both a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner.
Combining a PET scan with an MRI or CT scan can help make the images easier to interpret.
Common uses of the procedure
PET and PET/CT scans are performed to:
- Detect cancer.
- Determine whether a cancer has spread in the body.
- Assess the effectiveness of a treatment plan, such as cancer therapy.
- Determine if a cancer has returned after treatment.
- Determine blood flow to the heart muscle.
- Determine the effects of a heart attack, or myocardial infarction, on different areas of the heart.
- Identify areas of the heart muscle that would benefit from a procedure such as angioplasty or coronary artery bypass surgery (in combination with a myocardial perfusion scan).
- Evaluate brain abnormalities, such as tumors, memory disorders, seizures and other central nervous system disorders.
- Map normal human brain and heart function.
How you should prepare for a PET and PET/CT scan
For a PET/CT scan, at least 6 hours of starvation process is required since eating may alter the distribution of the PET tracer in your body and can lead to a suboptimal scan. This could require the scan to be repeated on another day, so following instructions regarding eating is very important. You should not drink any liquids containing sugars or calories for several hours before the scan. Instead, you are encouraged to drink water. If you are diabetic, you may be given special instructions.
Women should always inform their physician or technologist who are performing the exam if there is any possibility that they are pregnant or if they are breastfeeding. The physician and technologist should always be informed about any medications, vitamins and herbal supplements you are taking. They also have to be informed about allergies and recent illnesses or other medical conditions.
You will receive specific instructions based on the type of PET scan you are undergoing.
Metal objects including jewelry, eyeglasses, dentures and hairpins may affect the CT images and should be left at home or removed prior to your exam.
How the procedure will be performed
First of all patients’ blood sugar will be measured. When the blood glucose is at the desired level, radioactive material will be injected intravenously depending on the type of nuclear medicine exam you are undergoing. There are several radioactive substances, but the most common used is the F-18 Fluorodeoxyglucose. This material, called Fluoro-18 is a sugar based molecule which is bound to the radioactive substances. There are also many other radiopharmaceuticals which are used routinely.
Following the injection, the patient is kept for approximately an hour to disperse the radiotracer through the body and to be absorbed by the organ or tissue being studied. During this procedure you will be asked to rest quietly, avoiding movement and talking. Then, the PET-CT scans will be taken. Total scanning time is approximately 30 minutes.