nuclear radiation in medicine

• Radioactive isotopes


  Used widely in medicine
• Using a radioactive tracer to explore internal organs


  1. Patient ingests/injects radioactive solution

  2. Radiation passes through body

  3. Radiation detected

  4. Diagnosis of organ function
• Radioactive tracers used


  • Iodine to check thyroid function
  • Different isotope to visualize bone damage/tumors
• Ideal properties of radioactive tracers

  • Emit gamma or beta radiation (not strongly ionizing)
  • Do not decay into another radioactive isotope
  • Have a short half-life
• Radiotherapy


  Using ionizing radiation to destroy unwanted tissue, especially cancers
• External beam radiotherapy


  1. Gamma radiation source outside body

  2. Radiation passes through body to target tumor

  3. Healthy tissue also damaged
• Internal radiotherapy


  1. Radioactive source placed inside body

  2. Radiation targeted to tumor

  3. Less damage to healthy tissue
• Radioactive isotopes have other medical uses besides tracers and radiotherapy