What are the applications of radioactivity in medicine?

Radioactivity is used in medicine for both diagnostic and therapeutic purposes.

Radioactivity plays a crucial role in the field of medicine. One of its primary uses is in the diagnosis of various diseases. This is achieved through nuclear medicine imaging techniques such as Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT). These techniques involve the use of radioactive tracers, which are substances that emit radiation and can be detected by special types of cameras. The tracers are injected, swallowed or inhaled into the body, and they accumulate in the area to be examined. The radiation emitted by the tracers is then detected and used to create images of the inside of the body. This allows doctors to detect abnormalities such as tumours, infections, or other diseases.

Another significant application of radioactivity in medicine is in the treatment of diseases, particularly cancer. This is known as radiotherapy. In radiotherapy, high-energy radiation is used to kill cancer cells and shrink tumours. The radiation can be delivered externally, from a machine that directs the radiation at the cancer (external beam radiotherapy), or internally, where radioactive material is placed inside the body near the cancer (brachytherapy). Radioactive iodine (I-131) therapy is another form of internal radiotherapy, used to treat certain types of thyroid cancer.

Radioactivity is also used in sterilisation of medical equipment. Radioactive cobalt-60 is commonly used to sterilise single-use medical products such as syringes, implants, and surgical instruments. The high-energy gamma rays emitted by cobalt-60 effectively kill bacteria, viruses, and other pathogens, ensuring the sterility of these products.

In summary, the applications of radioactivity in medicine are vast and varied, ranging from diagnostic imaging to therapeutic treatment and sterilisation of medical equipment. Its use has revolutionised the field of medicine, allowing for more accurate diagnoses and effective treatments.