4.3.3 Uses of Nuclear Radiation

• Nuclear radiations are used in medicine for the:

  • Exploration of internal organs
  • Control or destruction of unwanted tissue
• What will happen to cells that receive a large dosage of radiation?

  The cells will die.
• Exposure to a large dose of radiation can lead to radiation sickness. Which symptoms are common symptoms of radiation sickness?

  Tiredness, vomiting and hair loss.
• Exposure to low levels of radiation over long periods can lead to cancer. Why is this?


  Radiation can cause mutations in our DNA which may cause our cells to divide uncontrollably.
• What is radiotherapy?

  Radiotherapy is the use of targeted doses of radiation to kill cancerous cells.
• What is external radiotherapy?

  External radiotherapy is where the cancerous cells are exposed to gamma radiation from outside of the body, from lots of different angles. This way, only the cancer site gets the highest dose of radiation.
• What is internal radiotherapy?

  Internal radiotherapy is where the cancerous cells are exposed to radiation from inside the body. The radiation source usually emits beta particles, and is placed inside or near the cancer cells.
• What are the side effects of radiotherapy?

  • The radiation also kills healthy cells
  • The patient feels sick
• How medical tracers work:

  1. A radioactive isotope (known as a tracer) is injected or swallowed by a person.
  2. If the tracer is injected, the tracer will travel to parts of the body through the blood.
  3. If the tracer is swallowed, the tracer may be absorbed through the persons intestine and then travel via the bloodstream.
  4. In both cases, the position of the tracer can be detected from outside the body because it emits radiation.
  5. We can use this technique to see the movement and accumulation of the tracer inside the body.
• True or false? Medical tracers are used to help diagnose medical problems.

  True - medical tracers allow us to locate or track things (such as tumours) within the body. 
• Whenever using radiation in medicine, it is always important to weigh up the pros and cons.  Although radiation can be used to help diagnose disease and to treat cancers, it can also cause cancers and radiation sickness. 
• For medical tracing we usually use radioactive isotopes that:

  1. Have a short half-life, to minimise the time that the patient is exposed to radiation.
  2. Produce gamma radiation because it is less ionising.