Nuclear medicine is the field of medicine in which various diseases are diagnosed and treated through use of radioactive materials. Nevertheless, people tend to find it a little frightening because of the involvement of the words “nuclear” and “radiation”. In reality, the developments in this field have importance for early diagnosis of many diseases. This, in turn, makes it possible for treatments to yield results that put a smile on everyone’s faces. The tests that are applied in the field of nuclear medicine differ from radiological examinations in that they involve use of radioactive materials and reveal the functioning of tissues and organs as well as providing anatomic images. We have consulted Professor Erkan Vardareli, a nuclear medicine specialist at Acıbadem Kozyatağı Hospital and head of the Nuclear Medicine Department in the Faculty of Medicine at Acıbadem University, on the radioactive materials that are used, as well as their effects and the tests that are performed in the field. Professor Vardareli explains the matter and states that the radioactive materials used in nuclear medicine tests vary, depending on the organ on which the tests are performed.
Vardareli says, “It is a natural response for people to be alarmed when the word “radioactive” is mentioned. However, the dosage of the radioactive materials that we use is extremely low. Therefore, the harmful effects these materials may have on human health are considered to be at a negligible degree, almost non-existent. All of our studies are within limits prescribed by the International Atomic Energy Agency. As a result, the applied radiation dozes are not at a level that is threatening for the health of patients. For instance, the amount of the radioactive materials used for thyroid scintigraphy is equal to the amount the body is subjected when the individual travels on a plane for two hours or sunbathes at the seaside for a few hours”.
Nuclear medicine tests consist of various tests that are specific to an organ or a group of certain diseases. These procedures, which were formerly referred collectively as “scintigraphy tests”, now differ among themselves, depending on each organ and purpose of use. PET, which is the abbreviation for Positron Emission Tomography, is one of these tests. This procedure, which makes it possible for important body function indicators such as blood flow, oxygen use and sugar metabolism to be assessed by providing images of normal or pathologic tissues in accordance with uptake of metabolic and radioactive materials that are administered intravenously. Since PET scans are usually performed together with the Computed Tomography scans, the two procedures are also collectively referred to as PET-CT. PET-CT provides aid in determination of the area in which the abnormal body activities occur.
The type of radioactive material to be used depends on the organ which is intended to be examined. For instance, while fluorine-labeled glucose is a general tumor marker, gallium 68 PSMA is used particularly for prostate cancer scans. DOTE, on the other hand, is a marker specific to neuroendocrine tumors.
In addition to diagnosis methods, radioactive materials are also beneficial in treatment. In the event that tests reveal prostate cancer lesions in a patient, certain molecules taken from the patient are labeled with a high-energy radioactive material referred to as lutetium 177 and injected back into the body of the patient for treatment purposes.
PET-CT is especially effective on oncology patients. The method is also used for certain neurologic diseases, as well as cardiac diseases. The ratios of PET-CT use per field is 90% for oncology, 5% for neurology and 5% for cardiology. PET-CT has considerable significance for diagnosis of coronary artery disease as well. Patients who suffer from myocardial infarction are usually expected to have dead cells in the entire area of infarction. However, it is possible for some parts of the tissues to hibernate with a lower amount of blood supply in order to survive. When the blood supply to such areas is restored to its normal state through endarterectomy (opening of an artery), the tissues recover. Cardiac PET provides important information on both these tissues and the potential for by-pass operations.
Another one of the nuclear medicine tests is densitometry which is used for measuring the mineral density in bones. In cases where there is loss of minerals in bones, this test makes it possible for the risk of fractures to be identified and the patient’s response to treatment to be evaluated. Bone density can be determined in only 10 minutes through administration of a low dose of X-rays to the patient. Densitometry tests are generally required by people of advanced age.
Scintigraphy is the general term used for the imaging procedures performed through use of radioactive materials and gamma cameras. Scintigraphy is useful identification of problems in the thyroid gland, liver, spleen, stomach, bowels, kidneys, gallbladder, heart, lungs, blood vessels and bones. Scintigraphic findings make it possible for many diseases to be diagnosed early.
Gamma probes, of which the use has increased in recent years, are nuclear medicine detectors that monitor gamma or beta radiation. These devices, which are only as big as pens, are kept sterilized in the operating room. They help in detection of the areas where lesions are located by identifying the regions of radioactive material uptake and make it possible for the correct areas to be treated through open surgery procedures.
Professor Vardareli states that nuclear medicine is one of the most popular fields of specialty and says, “The doctors who become aware of the benefits of the PET-CT device are the ones who prefer its use on an increasing basis. The first PET-CT device under the Acıbadem Healthcare Group roof was integrated in 2002. That year, 52 patients were scanned with the device. The number for this year, on the other hand, is 1400. When the said 52 patients were scanned, there were only three PET-CT devices in Turkey. Today, this number has reached approximately 100”.
Professor Erkan Vardareli has provided us with the following information on the history of nuclear medicine in Turkey: “The history of nuclear medicine in our country is not a long one but the developments occur very fast. In the 1950s, Professor Suphi Artunkal established a laboratory in Haseki Hospital, which was then known with the name Treatment Clinic Foundation. The professor was, in fact, an endocrinologist and he conducted studies on thyroid functions. In the later years, a radioisotope laboratory was established within the Internal Diseases Department in the Faculty of Medicine at Ankara University. The specialists working in this laboratory conducted studies as well. When the developments in the rest of the world picked up speed, Turkey adapted to it. When we compare the country to the rest of the world today, we have absolutely no shortcomings in routine, patient diagnosis or treatment. Whatever can be done in the world can be done in Turkey as well.”