PET-Scan (PET-CT) in Turkey | Precision imaging and rapid diagnosis

What is a PET-Scan or PET-CT?

The PET scan, or Positron Emission Tomography (PET), is an advanced nuclear medicine imaging technique that allows visualization of the metabolic activity of tissues. In practice, the PET scan is often combined with a standard CT scan, hence the term PET-CT.

Unlike an MRI or a basic CT scan that shows the structure of organs, the PET scan reveals how the body's cells are functioning. It can therefore detect some abnormalities even before they become anatomically visible.

In other words, the PET scan doesn't just show “where” a lesion is, but also “how it behaves.”

If you need to undergo a PET scan or simply wish to learn more, our teams in Turkey are available to assist you and answer all your questions.

How does the test work?

The PET-CT scan works by injecting a mildly radioactive tracer into the bloodstream, usually glucose-based. This tracer is preferentially absorbed by cells with high metabolic activity, such as cancerous, inflammatory, or infectious cells.

Cells that consume a lot of energy absorb more of this tracer, allowing the scanner to detect specific signals known as positron emissions. Using highly sensitive detectors, the PET scan can accurately identify areas of abnormal activity, also referred to as “hot spots.”

These images not only provide the exact location of abnormalities but also offer crucial insight into their function and progression. This makes the PET scan an essential tool in the diagnosis and monitoring of numerous conditions, especially cancers, infections, and certain neurological disorders.

When is PET-Scan recommended?

PET-Scan is now a reference tool in many medical specialties. It is especially useful in oncology, neurology, and cardiology, thanks to its ability to detect early cellular-level abnormalities.

Its main indications include:

• Cancer detection and tumor visualization (lung, breast, colon, brain, thyroid, lymphoma, etc.),even before tumors are palpable or clinically apparent.
• Searching for metastases or recurrence after treatments like surgery, chemotherapy, or radiotherapy.
• Staging of tumors, to assess how far they have spread in the body.
• Neurological disorders, such as Alzheimer's disease, epilepsy, or Parkinson's disease.
• Certain cardiovascular diseases, particularly to analyze ischemia or assess the viability of heart muscle.
• Therapeutic monitoring, by measuring the effectiveness of chemotherapy, immunotherapy, or radiotherapy.

It is essential to consult a doctor to determine whether a PET-Scan is the most appropriate exam for your situation and to fully understand its potential benefits and risks.

Are you considering a PET-Scan or looking for a second medical opinion before making a decision? Our specialists in Turkey are here to listen, guide you step by step, and offer personalized support.

Contact us today to ask your questions or book a free and confidential teleconsultation with an expert.

Specific contraindications

Although PET-Scan is a non-invasive and generally well-tolerated examination, certain situations require precautions or may represent temporary contraindications.

• Pregnant or breastfeeding women: Due to even low-level radiation exposure, this exam is generally avoided during pregnancy and breastfeeding, unless medically justified in an emergency.
• Poorly controlled diabetic patients: High blood sugar competes with the glucose-based radioactive tracer, so less tracer is absorbed by the cells of a tumor. This can make the results less reliable and can lead to false negatives (a tumor that is present but under-detected) or an inaccurate assessment of the disease. It is therefore crucial that diabetes is stabilized before the scan.
• Claustrophobic individuals: The exam is performed while lying inside a tunnel-like scanner. If you suffer from claustrophobia, inform the team beforehand; accommodations can be arranged (mild medication, reassuring support, etc.).
• History of allergy to contrast agents: While PET-Scan rarely uses iodine-based contrast, some PET-CT protocols may involve it. Be sure to mention any known allergies before the exam.

Possible side effects of the tracer injection: they are uncommon and usually minor, such as discomfort, bruising or bleeding at the injection site. An allergic-type reaction to the tracer is possible but very rare. Tell the team about any previous allergic reaction and about the medications you take before the exam.

How is a PET scan performed in Turkey?

PET-Scan is a generally well-tolerated outpatient procedure. It does not require hospitalization and is typically completed within a few hours.

Here are the key steps of the procedure:

1. Preparation for the exam: You will need to fast for 4 to 6 hours before the scan. Upon arrival, a nurse will check your blood sugar level to ensure the tracer will be properly absorbed by your body. It is important to avoid intense physical activity the day before.
2. Tracer injection: A mildly radioactive tracer is injected intravenously. Most commonly, it's FDG, a glucose-based compound marked with fluorine. As with any intravenous injection, you may feel brief discomfort at the injection site.
3. Waiting period: After the injection, you will rest comfortably in a quiet room for 30 to 90 minutes. This allows the tracer to distribute and accumulate in tissues with high metabolic activity (such as tumor cells).
4. Scanning: You will lie on a motorized table that slowly slides through a scanning ring. The scan itself takes about 20 to 30 minutes and is painless, but you must lie still. Some people find the scanner confining, so tell the team beforehand if you are anxious or claustrophobic.
5. After the exam: Once the scan is complete, you may return home immediately. Side effects are uncommon (see above),and it is recommended to drink plenty of water in the following hours to help flush the tracer from your body.

Limits of PET-Scan diagnosis

PET-CT is not always the first-line examination. In some cases, it is used as a complementary test to other imaging methods, to refine a diagnosis or assess treatment response.

PET-Scan has shown limitations in the following cases:

• Small lesions that may go undetected (false negative): Very small tumors (less than 5 mm) may emit signals too weak to be detected by the PET-Scan. This doesn't mean they don't exist, but rather that they fall outside the current detection capability. A negative result can therefore be a false negative, meaning that a cancer is present but has not been detected. A normal PET-Scan does not completely rule out disease, and other examinations may be needed.
• Risk of false positives: The PET-Scan detects any high metabolic activity… which can also occur in infections, inflammation, or even localized trauma. It may suggest a malignant tumor when there is none. A false positive can lead to additional examinations, sometimes invasive such as a biopsy, and to significant anxiety. A suspicious PET-Scan finding must therefore always be confirmed by other tests, such as a biopsy, before any treatment decision.
• Certain cancers that are less visible: Some slow-growing cancers, such as prostate or liver cancers, absorb very little of the radioactive tracer. As a result, they may go unnoticed or appear less clearly than more metabolically active tumors.

Radiation exposure: the tracer injection, and the CT part of a PET-CT, deliver a dose of radiation. For an FDG PET-CT, the sources consulted indicate a typical dose of about 7 to 15 mSv, depending on the equipment and on whether a low-dose or a diagnostic-quality CT is used (NHS patient information; US clinical trial protocols). For comparison, natural background radiation is roughly 2 to 3 mSv per year, and a chest CT scan delivers about 8 mSv.

Any radiation exposure, even low-level, is a known risk factor for developing cancer many years later. The risk is proportional to the dose received and adds up with repeated exposures (cumulative dose). Children and unborn babies are more sensitive to radiation, which is why the exam is generally avoided during pregnancy. If you have already had many scans or radiation treatment, tell your doctor so that your cumulative dose is taken into account. When the exam is medically indicated, the expected diagnostic benefit is generally considered to outweigh this small risk, and you should discuss it with your doctor before the exam. The radioactivity of the tracer decreases quickly and is gone from the body within a few hours.

What are the alternatives to PET-Scan in Turkey?

Depending on your medical history and the areas to be examined, other imaging or diagnostic tests may be recommended, either on their own or in addition to a PET-Scan. Here's an overview of the most common options:

Every case is unique. That's why our specialists guide you in choosing the most appropriate tests for your situation, avoiding unnecessary procedures and ensuring a smooth and personalized care path.

Do you have questions or need personalized guidance? Our specialists in Turkey are available to answer your concerns, review your test results, and advise you on any additional tests that may be needed.