Medical Uses of Radiation

Types of Radiation Used in Medicine

Different types of radiation have important medical applications due to their penetrating power and interaction with living tissues:

• Gamma rays are used for sterilisation of medical equipment because their high energy kills bacteria and viruses without heating the instruments.
• X-rays are widely used for medical imaging, especially to view bones and internal structures.
• Beta radiation is used in cancer treatment to destroy cancer cells by damaging their DNA, preventing them from dividing. Beta radiation has less penetrating power than gamma rays and X-rays, making it suitable for targeting cancer cells near the surface.

Medical Imaging Techniques

Medical imaging allows doctors to see inside the body without surgery, using radiation in different ways:

• X-rays pass through soft tissues but are absorbed by denser materials like bones, producing images of broken bones or dental checks.
• CT scans (Computed Tomography) use X-rays taken from many angles to create detailed cross-sectional images of the body, helping diagnose diseases or injuries.
• Radioactive tracers are substances containing small amounts of radioactive material that are injected or swallowed. They emit gamma rays, which are detected by special cameras to track blood flow or organ function.

For instance, a radioactive tracer can be used to check how well the heart is pumping blood or to detect blockages.

Radiation in Cancer Treatment

Radiotherapy uses high-energy radiation to treat cancer by targeting and destroying cancer cells:

• Gamma rays are commonly used in radiotherapy because they penetrate deep into the body to reach tumours.
• The radiation damages the DNA inside cancer cells, stopping them from dividing and causing them to die.
• Doctors carefully plan treatment to minimise damage to healthy tissue, using precise beams and controlled doses.
• Beta radiation is also sometimes used in cancer treatment, especially for surface tumours, due to its lower penetration depth.

This targeted approach helps reduce side effects and improves the chances of curing the cancer.

For example, if a tumour is 5 cm deep, gamma rays can be directed to that depth, sparing surrounding healthy tissue as much as possible.

Safety and Precautions

Because radiation can harm healthy cells, safety is crucial in medical use:

• Shielding and protection: Lead aprons and walls protect patients and medical staff from unnecessary exposure.
• Controlled doses: The amount of radiation used is carefully calculated to be as low as possible while still effective.
• Risks vs benefits: The benefits of using radiation for diagnosis or treatment must outweigh the small risks of exposure.
• Monitoring exposure: Medical staff often wear dosimeters to track their cumulative radiation exposure over time.

Medical staff are trained to use radiation safely, and patients are monitored to limit exposure.