PET-CT (Positron Emission Tomography-Computed Tomography) is a powerful imaging technique that combines functional information from …
PET-CT
PET-CT is a molecular imaging method in which metabolic changes caused by diseases in the body are displayed using radioactive compounds (radiopharmaceuticals). Early diagnosis of cancer, heart disease and some neurological diseases, identification and planning of appropriate treatment make significant contributions to the evaluation of the treatment response. Functional and structural changes in PET-CT imaging can be evaluated together.
How does PET-CT work?
PET-CT is a combination of Positron Emission Tomography (PET) scanning and Computed Tomography scanning, obtained with one equipment at a time. The PET scan provides important information about the body’s metabolic activity and physiology, while CT images allow to identify anatomical changes in the body. Cancer cells have higher metabolic rates than normal cells, which occur as denser areas in PET screening. Many neurological diseases and heart diseases, especially cancer, change the biological processes of the body. PET can often discover these changes in the early stages before any complaints (symptoms) occur.
Before the start of screening, a radiopharmaceutical patient is injected.
Radioactive substance usually varies depending on the type of cancer, but the most commonly used radiopharmaceuticals in cancer imaging are fluorine 18-Fluorodeoxyscose (18F-FDG) and Gallium-68 marked peptide compounds (Ga-68 DOTA-TATE or Ga-68 PSMA).
PET scanners detect and record signals emitted by radioactive material. These signals are then converted to real images through a computer. Screening takes about 20 minutes for most patients.
PET-CT in oncology
PET-CT is effective in determining whether the affinity type of cancer is present to radioactive compounds used in imaging, its spread throughout the body, and in planning treatment and evaluating response. Imaging the whole body with a single imaging is an important advantage.
Particularly effective are lung, head and neck cancers, breast cancer, colorectal cancers, esophagus, stomach cancer, neuroendocrine cancers, lymphoma, melanoma, gynecological There are cancers, sarcomas, bladder and prostate cancers. It is also used in many other types of cancer in different groups and periods of the disease. The most important contribution to the treatment of cancer is to guide the selection of the most suitable treatment for the patient and prevent unnecessary treatments.
1.Early diagnosis
PET-CT provides an assessment of the metabolic activity of certain cancerous tissues in the human body and the characterization of tumors as benign or malignant. While preventing unnecessary biopsy processes in tissues defined as benign imaging, it contributes to the diagnosis by guiding the biopsy in tumors that are highly likely to be malignant.
2 Staging of Cancer
It is extremely effective in determining the spread of the disease throughout the body in many types of cancer. Confirmation of the presence or absence of metastatic disease also allows the selection of the optimal treatment for the patient.
3.Detection of relapses
In the early detection of relapses in patients who underwent cancer treatment, especially after radiotherapy and surgical treatments, the most is an effective imaging technique. It plays an important role in detecting recurrence and determining appropriate treatment in patients whose monitoring has been detected, but the source of recurrence is not detected by conventional imaging techniques.
4.Planning of radiotherapy therapy
Live tumor cell areas that will be irradiated in radiotherapy or radiation therapy can be most accurately determined with PET-CT imaging and unnecessarily increasing the effectiveness of treatment radiation that can be given to healthy tissues is prevented, resulting in a decrease in side effects.
5.Evaluation of the effectiveness of treatment
PET-CT is a imaging method that allows the treatment effectiveness after cancer treatment to be evaluated before imaging methods such as CT or MRI. Its predominance in this area is due to the detection of metabolic changes caused by cancerous cell death prior to the onset of structural shrinkage in cancer tissue. Treatment related changes in cancer tissue can be differentiated by comparing the images taken before, treatment and after treatment.
PET-CT in neurology
The ability of PET-CT technology to identify metabolic changes plays an important role in localizing epileptic foci in the brain, in the diagnosis of Alzheimer’s disease and other types of dementia.
PET-CT in cardiovascular diseases
Detecting areas with reduced blood flow caused by coronary artery blockages by showing both perfusion and metabolic activity in myocardial tissue and damage to the heart muscle can be used in determining. This information is important for patients who have previously suffered myocardial infarction and are scheduled for treatment.
PET-CT in breast diseases
Positron Emission Tomography (PET) and Computed Tomography (CT) for the first time achieved in the detailed imaging of the human body by using the two most superior imaging systems at the same time The miracle of high-tech PET-CT is what we know is used as a drug.
Sugar is connected by radioisotopes, which in a very small amount externally signal, and is given to the patient’s vein.
Radioisotope sugar has the ability to enter cancer cells, even though the breast is very small. Because cancer cells use a lot of sugar. This allows cancer to be caught when it is much smaller and easier to treat.
The task of CT in this system is to show where, like a map, very small cancer cells are located in the body.
PET-CT is the best of both methods. When two imaging variants are combined, the finest details of the body are revealed.
PET-CT appointment process
The radiopharmaceuticals used for PET-CT scans are specially prepared for each patient, and they quickly disappear with time as they become short-lived substances. That’s why it’s important that you come to your scan in time.
Avoid exhausting exercise or physical activity the day before your screening.
Drink at least 8-10 glasses of water, unless there is a fluid restriction by your doctor.
If you use insulin and oral anti-diabetic drugs due to diabetes, inform your doctor when you make your appointment.
You need to be hungry for at least 6 hours before shooting 18F-FDG PET-CT. It’s okay to drink water during this time. Your starvation time will be adjusted according to your appointment time.
When you come for viewing, exposure to cold may affect your image quality.
PET-CT is not applied in pregnant women. If you are breastfeeding, pregnant, or if you think you might be pregnant, please call the PET-BT department before your appointment. Remember to bring back reports and CDs of your previously made imagery (CT, MRI, PET-CT) and your pathology results when you arrive on your appointment.
PET-CT imaging process
Our nuclear medical nurse will take you to the injection room and ask you to read and sign the enlightened consent form so you can enter the filming. You will then be asked to answer some questions to learn your medical history.
Blood sugar level is measured before your injection of radioactive substance.
It is necessary that the blood glucose level is between 70mg/dL and 200mg/dL. If your blood sugar level is outside the recommended levels, or if you did not follow special instructions before your test (special diet, medications, fasting time, etc.), your appointment may need to be rescheduled.
After injection, it is necessary to wait about 60 minutes in the rest room allocated to you, so that the radioactive substance is dispersed in your body.
PET-CT post-imaging
Radiopharmaceuticals used in PET-CT are short-lived. Therefore, it does not pose a serious risk for radiation safety to your family and those around you. But avoid unnecessary long-term contact with young children and pregnant women, especially those who are at risk of radiation exposure for about 12 hours.
Since the radioactive substance is excreted through the urinary tract, flush the toilet several times after using the toilet on the day of the imaging is performed and wash your hands thoroughly.
After viewing, drink plenty of fluids and urinate often. This app helps you to remove the remaining radioactivity in your body from your body.
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