Radiation in medicine

• Radiotherapy

  Used to treat cancer
• Medical tracers


  Can help detect problems inside the body
• Ionizing radiation can damage cells


  By ionizing the atoms and molecules within them
• Large doses of radiation across the body


  Can lead to radiation sickness with symptoms like vomiting, tiredness and hair loss
• Radiotherapy


  Uses radiation to destroy cancer cells
• External radiotherapy


  1. Emits gamma rays targeted at the cancer site from lots of different angles

  2. Only the cancer site gets the highest dose
• Internal radiotherapy


  1. Places the radioactive source inside the body, either inside the cancer itself or next to it

  2. Usually uses beta radiation which is more damaging than gamma rays but can't pass as far through the body
• Radiotherapy and internal radiation methods have side effects as healthy cells also get damaged or killed
• Medical tracers


  Radioactive isotopes placed in the body that can be tracked to check organ function
• Gamma rays are used for medical tracers as they are less harmful than alpha or beta radiation
• Isotopes with shorter half-lives are used for medical tracers so they only emit radiation for a short period
• Radiation use must balance risks against benefits, e.g. medical tracers can help diagnose diseases but with minimal dose, while radiotherapy can save lives despite side effects