The Radiation Medicine Centre is a medical facility based on the  modern standards, equipped with the state-of-the-art equipment and staffed with highly qualified personnel, which is focused on providing high quality services to patients.

The Radiation Medicine Centre cares for patients’ health with its equipment and the best-trained staff, in radiotherapy, nuclear medicine and palliative radiotherapy departments.


What is PET-CT

PET-CT (positron emission tomography-computed tomography) is a diagnostic procedure used for diagnosing, treating, and monitoring various types of cancer.

PET-CT is the latest medical research technology in nuclear medicine that is used not only for detecting cancer but also for diagnosing various diseases. There are more than 100 types of malignant tumors, each presenting differently. The use of the latest technologies in nuclear medicine allows for the identification and evaluation of these tumors.

The information obtained from PET-CT scans is also important for long-term diagnosis, treatment, and monitoring. Leading oncology centers around the world have established multidisciplinary committees that include oncologists, surgeons, specialists from various fields, radiation therapists, anatomopathologists, radiologists, and nuclear medicine experts.

Mardaleishvili Medical Group is recognized as one of the top-level centers where nuclear medicine specialists successfully treat patients.

The experienced physicians of Mardaleishvili Medical Group emphasize the importance of PET-CT in the treatment of oncological diseases.

PET-CT allows for the simultaneous performance of two types of scans—positron emission tomography and computed tomography. In diagnostic medicine, computed tomography (CT) has been used for many years to scan the body and evaluate the anatomical details of a patient during screening or diagnosis.

With positron emission tomography (PET), we obtain information about how radiopharmaceuticals— radiolabelled substances that can assess the physiology of certain tumor sites or damaged tissues—are received in different malignant tissues in the body.

By combining these two methods—positron emission tomography and computed tomography—in one examination, provides both anatomical and functional-metabolic information of the tumors being studied. PET-CT is used in diagnostic protocols to determine the stage of malignant disease and monitor the body’s response to treatment.

In some cases, PET-CT helps us develop a radiation therapy plan for metabolically active tumors or metastases.

Furthermore, with PET-CT, we can evaluate the results of both immunotherapy and targeted therapy. We can also assess glucose metabolism, known as the Standardized Uptake Value (SUV), before and after therapy.

If the SUV value decreases during therapy, it indicates that the treatment is effective.

Today, SUV is one of the most important criteria for assessing the successful treatment of oncological diseases.

The most commonly used substance in PET-CT is radiolabelled glucose   18F-FDG.

At the first stage, the radiopharmaceutical (radioactive FDG glucose) is injected. After waiting for one hour, the patient’s body is then scanned. This allows the detection of areas with increased glucose metabolism, indicating the presence of malignant cells.

Today, other substances such as galactose-labeled gallium -68 PSMA (gallic membrane-specific prostatic antigen)   for prostate or gallium-68 DOTATED for neuroendocrine tumors are also used because they cannot be detected with FDG.

Therefore, CT PET scanning can be used in the diagnosis, monitoring treatment, and assessment of malignant tumors, primary tumors, or metastases to plan radiation therapy.

Patients are instructed to avoid eating for six hours before the procedure, but drinking water is allowed.

Only injectable radiopharmaceuticals without contraindications or allergic reactions are used. The waiting time is between 45 minutes to an hour, and the scan itself takes about 15 to 20 minutes.

This procedure is intended for F18-FDG. In the case of gallium-68, there is no need to observe a six-hour fasting period. Depending on the situation, results can be obtained on the same day or the following day.

All tumors are different and manifest in their own way. For example, invasive ductal breast cancer has the highest affinity for FDG, unlike lobular breast cancer. If you perform PET-CT for lobular cancer, you will not see any lesions.
Therefore, in breast cancer, PET-CT is conducted only for types with the highest affinity for FDG, such as invasive ductal carcinoma or ductal carcinoma in situ.

This means that PET-CT differs from other imaging methods because not all types of cancer have an affinity for FDG.
In PET-CT, the whole body is scanned using one imaging method, unlike other methods where each part of the body is examined separately.
Therefore, PET-CT is important for assessing the physiological activity of malignant tissues in any part of the body. There are cases when we investigate malignant tissue that has not yet been operated on after medical treatment but shows a reduction in metabolic activity after therapy.
Thus, PET-CT helps us evaluate the body’s response to treatment by using multiple criteria to assess treatment resistance.

PET-CT is considered in protocols that determine the most suitable method of cancer treatment, especially in the case of personalized molecular therapy.
We use tracking molecules for certain types of diseases. For example, in prostate cancer, PET-CT is conducted with gallium-68 PSMA. If malignant prostate tumors express prostate-specific membrane antigen, we can label it with lutetium, erbium, or actinium, allowing us to treat such tumors with high-energy radioactive components.
These treatment methods can be used in the early stages of prostate cancer to improve survival rates.
Other treatments such as surgery, chemotherapy, and radiation therapy are also used in early stages.
Magnetic resonance imaging (MRI) is recommended for screening and diagnosing prostate cancer.
However, to detect the disease before a biopsy, we conduct PET-CT using gallium-68 PSMA.

It depends on the patient and the extent of the injury.
If we are talking about lung cancer, the accuracy is 95 percent.
For other types of cancer, this figure may be comparatively lower because glucose metabolism is less intense.
The accuracy varies but is at least 90 percent for all types of malignant tumors.

We can use PET-CT in patients with neurological issues to study epileptic seizures in the brain, in cases of dementia, for differential diagnosis of Alzheimer’s disease, and in cases of cardiovascular diseases after a heart attack, to determine the presence of healthy heart tissue that can be revascularized.
PET-CT is the gold standard for detecting viable heart tissue after a myocardial infarction.
Therefore, based on the results of PET-CT, doctors can make optimal therapeutic decisions for patients.
For example, if PET-CT detects viable tissue after a heart attack, bypass surgery can be performed to revascularize the area.
If no viable tissues are visible, there is no point in performing the surgery.
The decision is based on the results of PET-CT. In patients with heart diseases, we use FDG.

PET-CT is mainly used to assess the body’s response to treatment. Post-treatment programs are important for cancer patients because they allow for the detection of potential relapses or metastases at an early stage.

Do PET-CT results correlate with tumor marker results in post-treatment programs?
In some types of cancer, marker evaluation is important in post-treatment programs, but this is not the only case.
In some types of cancer, such as colon, breast, and ovarian cancer, we correlate FDG uptake assessed by PET-CT with tumor markers.

I recommend performing PET-CT after biopsy. The anatomopathological report provides information about the type of tumor cells, invasiveness, and other aspects that need to be considered.

Diabetic patients require special attention when undergoing PET-CT with FDG. For the test to be performed, blood glucose levels must be below 200.
Therefore, if diabetes is controlled with medication and blood glucose levels are below 200, there are no problems.
But if blood glucose levels exceed 200, we cannot perform PET-CT with FDG due to the possibility of false-negative results.

PET-CT is also performed on newborns, although there are different approaches for adults.
The level of radiopharmaceuticals is adjusted for children, and we can perform all nuclear medicine procedures.
However, for children, we use anesthesia to perform the procedure.

Some patients ask us if they can undergo PET-CT instead of screening.
There are families with oncological history, people with first degree relatives diagnosed with various types of cancer.
If, for example, there is a family history of breast cancer, PET-CT can be performed as a screening method.