Nuclear medicine refers to medications that are attached to a radioisotope (radioactive material); the drug is called a radiopharmaceutical. Several different radiopharmaceuticals are available today to study various parts of the body and treat some conditions and diseases.
The radioisotope which is attached to the drug is usually called a “tracer”. The most common tracers used in nuclear medicine are thallium-201 and fludeoxyglucose (18F) (18F-FDG), gallium-67, indium-111), iodine-131, iodine-123, and technetium-99m.
The radiopharmaceutical is administered either by injection, orally (swallowing) or as an inhalation. It is designed to target a specific part of the body where there might be some abnormality or disease. The radioactive part of the drug emits gamma rays which are detected using a gamma camera. The doctor can then see what is happening inside the body.
Nuclear medicine can, for example, be used to identify lesions deep inside the body without having to open up with patient (surgery). It can also determine whether certain organs are working properly; it can determine whether the heart is pumping blood adequately, or whether the brain is getting enough blood, and whether the brain cells are functioning properly.
After having a heart attack, nuclear medicine procedures can help accurately assess the damage to the patient’s heart.
Nuclear medicine can also be used to treat patients. Thousands of people with hyperthyroidism are treated every year using radioactive iodine. Certain types of cancers, as well as bone pain resulting from cancer can also be treated.
With the most advanced equipment, nuclear medicine images can be used almost simultaneously with CT scans, making detailed anatomical studies possible.