Its main fields of action are the diagnostie imaging and the treatment of specific diseases through the use of radiopharmaceuticals.

The clinical applications of the radiopharmaceutical practically cover all medical specialties.

(1) Definition adopted by the National Commission of Nuclear Medicine Specialty

Diagnostic

The diagnostic techniques of nuclear medicine provide essentially functional information of the organ studied, unlike other diagnostic imaging (TAC, magnetic resonance, ecography, etc) that provide structural or anatomical information. With positron emission tomography (PET) the information provided is molecular in nature.

Nuclear medicine techniques are non-invasive as they only require administration to the patient, generally intravenously, of a radiopharmaceutical.

Once the radiopharmaceutical is inside the body it fixes to a tissue, organ or determined system and can be followed from outside as it emits small amounts of gamma radiation that are detected by gamma chambers. This radioactive signal emitted is amplified and transformed into an electrical signal that is then analyzed by computer and converted into images of the organ studied.

The choice of radiopharmaceutical depends on the tissue, organ or organic system under study.

Nuclear medicine explorations are highly safe as the radiopharmaceuticals of diagnostic use are administered in extremely low doses (so-called tracers), therefore they have no drug-treatment action, no secondary effects or serious adverse reactions. Also, the amount of radiation received by a patient subject to nuclear medicine exploration is similar or less than that received in a conventional radiological exploration.

To date, there are almost 100 types of nuclear medicine explorations that allow early diagnosis in bone pathology, cardiology, oncology and endocrinology as well as in neurology, nephro-urology, pneumology, hematology, digestive system, infectious pathology, peripheral vascular system and pediatrics.

Most nuclear medicine studies are "in vivo" wherefore it is necessary to administer the radiopharmaceuticals to the patient to obtain the necessary information via external radiation detection. "in vitro" studies do not require administration of radiopharmaceuticals to the patient and only biological samples are processed. Finally, there are "in vivo/vitro", studies based on the measurement of biological samples after having administered a radiopharmaceutical to the patient.

In the latter decades of 20th century and the beginning of the 21st century, new techniques have been developed in the field of nuclear medicine, such as single photon emission tomography (SPECT) or Positron emission tomography (PET). These advances have given rise to the appearance of new radiopharmaceuticals.

Nuclear Medicine Treatment

From a treatment point of view, nuclear medicine has its main applications in thyroid cancer, hyperthyroidism and palliative treatment of bone pain of metastasic origin in specific cancers.

The treatment with radionucleides is carried out with beta radiation emitters, generally of high energy.

At present, radiopharmaceuticals are being researched for the treatment of many diseases and most of these drug products are expected on the market soon.