Nuclear medicine is the medical specialty that uses, in small quantities, radioactive materials produced for medical purposes, with the aim of diagnosing and/or treating certain diseases. The main differential of the specialty is the possibility to assess the function of several organs, in a safe and non-invasive way.
Used for years for the diagnosis of cancer, nuclear medicine involves the use of radioactive substances, the so-called radiopharmaceuticals, which target exclusively the lesions, where gamma emissions provide the oncologist with information about the location, shape and physiology of the tumor.
PET/CT is one of the most important exams in the diagnosis and monitoring of tumors. It is a combination of two diagnostic specialties in just one imaging exam: positron emission tomography (PET) and computed tomography (CT) offers greater accuracy of results, making it able to more easily manage neoplasms and detect tumors in the whole body of the patient in a single exam.
NUCLEAR MEDICINE EXAM
Tests for the identification and follow-up of cancer by nuclear medicine are performed by ingesting radioactive material orally, intravenously or being inhaled in the form of a gas (although this is rare). Administration may be from a few minutes to several hours before the test. For example, in a bone gammagraph, the marker is administered approximately 2 hours before the start of the study. For gallium gammagraphs, the marker is administered a few days before the exam.
In most cases, a nuclear medicine test is performed as an outpatient procedure. Because of the special materials and equipment required, these tests are usually performed in a hospital’s radiology and nuclear medicine department. During imaging, the patient will need to remove any jewelry or metallic objects that may interfere with the scan result. The exam does not cause pain. However, you may feel uncomfortable after lying on the exam table for a long time.
A nuclear medicine test takes about 30 to 60 minutes, plus the waiting time after the radioactive material is administered. For bone exams, the material takes 2 to 3 hours to be absorbed and the exam takes about 1 hour. Gammagraphs with the use of gallium take several days between the injection and the actual exam. The results of nuclear medicine tests are usually available within a few days.
Possible Complications and Side Effects
In general, nuclear medicine tests are safe. Radiation doses are very small and radionuclides offer a low risk of toxicity to provoke an allergic reaction. Although rare, some patients may experience pain and swelling where the material is injected.
TYPES OF CANCER TREATED WITH NUCLEAR MEDICINE
Prostate cancer – One of the treatments in the field of nuclear medicine is the use of the radioactive lutetium-labeled PSMA-1 molecule, used in the treatment of metastatic prostate cancer, when the disease has already spread to other organs. As the PSMA-1 molecule is able to bind to the PSMA protein, which is found in malignant prostate cancer cells, by labeling the molecule with the radioisotope of lutetium, this substance is absorbed, destroying the tumor cells.
Skin cancer – In cases of more advanced cancers, such as melanoma, it can help both to identify the Sentinel Lymph Node, which detects whether a particular tumor has invaded the patient’s lymph nodes, and PET/CT.