What are the uses of radioactive isotopes?

Sometimes a special compound is added separately to some parts of the body. It is possible to get important information about the organ by looking at the amount of that compound. To understand the amount of the compound, one of the atoms of the compound is replaced with a radioactive isotope, and the amount of the compound in a certain organ can be understood from the radiation of that radioactive isotope. Usually, the isotope emits gamma rays and these gamma rays can be detected externally.

A striking example of the use of radioactive isotopes is Positron Emission Tomography (PET). Whereas the radioactive isotope emits a positron. It combines with electrons and converts them into energy. These two energies are emitted in opposite directions as gamma rays. Therefore, by detecting two gamma rays of specific energy in opposite directions, the source of the positron can be deduced. From that information, we can not only know the existence of positron production but also tell exactly where and how much there is. By adding such an isotope to glucose by emitting positrons, we can use PET to find out how much glucose is stored in the brain. From this information, it is possible to extract the information on which part of the brain is more active and used more glucose. PET technology has played a revolutionary role in revealing the workings of the human brain.

Radioactive isotopes are used not only to diagnose diseases or determine the functioning of organs. Diseases are also cured with it. Cobalt-60 is a gamma ray emitting isotope, using this isotope to destroy cancer cells with gamma rays. Iodine-131 is used in the treatment of the thyroid gland. It is so effective in thyroid treatment that thyroid surgery is not required these days. Besides, phosphate-containing radioactive isotope phosphorus-32 is used in the treatment of blood cancer called leukemia.