6.6 - Using Radiation in Medicine

• What is radiotherapy used for?

  To treat cancer
• What are medical tracers used for?

  To detect problems inside the body
• What type of radiation can damage cells?

  Ionizing radiation
• How does ionizing radiation affect atoms and molecules?

  It ionizes them, causing damage
• What is a major problem caused by ionizing radiation?

  It can mutate our DNA
• What happens if cells receive a large enough dose of radiation?

  They can be killed off completely
• What is radiation sickness?

  Illness from large doses of radiation
• What are common symptoms of radiation sickness?

  Vomiting, tiredness, and hair loss
• How can radiation be beneficial in medicine?

  It can destroy unwanted cells like cancer cells
• What is the process of using radiation to treat cancer called?

  Radiotherapy
• What are the two main methods of delivering radiation in radiotherapy?

  Externally and internally
• What type of radiation is typically used in external radiotherapy?

  Gamma rays
• How is radiation targeted in external radiotherapy?

  From different angles at the cancer site
• What type of radiation is used in internal radiotherapy?

  Beta radiation
• Why is beta radiation used internally?

  It is more damaging than gamma rays
• What is a downside of both external and internal radiotherapy?

  Healthy cells can also be damaged
• What are medical tracers made of?

  Radioactive isotopes
• How can medical tracers be introduced into the body?

  By injection or ingestion
• What do we track to monitor medical tracers?

  The radiation they emit
• What is the purpose of using iodine-123 in medical tracers?

  To check thyroid gland absorption
• Why do we prefer gamma rays for medical tracers?

  They are less harmful than alpha or beta
• What is the ideal half-life for isotopes used in medical tracers?

  As short as possible
• Why is it important to minimize radiation risk in medical tracers?

  To reduce harm while diagnosing diseases
• What is the benefit of radiotherapy in cancer treatment?

  It can save a person's life
• Why might some patients refuse radiotherapy?

  If it only extends life briefly
• What should we consider when using radiation in medicine?

  Weighing risks against benefits
• What is the general approach to using medical tracers?

  To diagnose diseases with minimal risk
• What is the conclusion of the video regarding radiation in medicine?

  It can be useful but also harmful
• 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 three symptoms are common symptoms of radiation sickness?

  • Hair loss
  • Tiredness
  • Vomiting
• 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 
• Radiotherapy is the use of targeted doses of radiation to kill cancerous cells.
• 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.
• 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. 
• 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. 
• 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.