Nuclear medicine is a particular field of medicine that uses substances, called radiopharmaceuticals, composed of a pharmacologically active part and a radioactive part. The pharmacologically active part has the property of being located in certain structures and in certain organs, which become visible thanks to the radioactive component. We asked Professor Arturo Chiti, head of PET and Nuclear Medicine at Humanitas, how it works, what are the fields of application and what risks it carries.
Bone Scintigraphy and Applications in Oncology
Nuclear medicine is more widely used in oncology, but not only. An example of nuclear medicine is bone scintigraphy, a practice according to which a substance is injected that is localized in correspondence to an increased remodeling of the bone, where the dead bone is eliminated and replaced with new bone: “This happens very often in the case of tumor diseases – said the specialist -. The more the location of the substance, the greater the radiation emitted. Thanks to the machinery we observe a greater concentration of radiation in a given area and so we understand the distribution of the drug and therefore the location of the disease”. In most cases the administration takes place by intravenous injection: the substance is distributed in the body and through special machines we can see where this happens, thanks to the radiation that allows you to locate the drugs.
From oncology to other medical specialties
In addition to oncology, nuclear medicine is used in the diagnosis and treatment of certain neurological diseases: “Certain radiopharmaceuticals are able to locate the presence of deposits of amyloid substance and thus help us to assess patients who may have dementia type Alzheimer’s“, stressed the specialist. “Depending on the drug used, in fact, we can see different things: for example, the amount of blood that reaches the heart in patients with ischemic disease; we can see radiopharmaceuticals that are localized according to the flow present in the coronary arteries and this allows us to see if there are areas of the heart that are less sprayed, for example under stress.
Focus on risks
“It depends on the type of radionuclide, so how the part of the radioactive drug that is used is made – said Chiti -. There are more dangerous radionuclides, which must be treated with greater caution, and others instead of exhausting the amount of radioactivity very quickly. Today, in modern diagnostics, almost all of the radiopharmaceuticals used have a very low half-life, i.e. a very low duration of radiation. Precautions therefore vary according to the drug that is used, but in most examinations these are very simple precautions.