What is radiotherapy?
Radiotherapy is the use of radiation to treat cancer. Around 50% of people with cancer will have radiotherapy. It can be given alongside other cancer treatments such as chemotherapy or surgery, or it can be given on its own. Radiotherapy can be used to eliminate cancer, reduce the chance of cancer coming back or relieve symptoms caused by cancer.
Radiotherapy can be given from outside of the body (external radiotherapy) or from inside the body (internal radiotherapy). The most common form of radiotherapy is external beam radiotherapy where a machine is used to aim an external source of radiation towards the affected part of the body, the radiation penetrates through the body to the area of cancer. Internal radiotherapy is where the radioactive source is inside the body. This can be radioactive implants that are placed very close to the tumour or radioactive liquids that are absorbed at the site of the tumour.
How does radiotherapy work?
Radiotherapy works by destroying cancer cells in the area that’s being treated. Radiation damages the DNA inside cancer cells causing the cells to stop multiplying. The cancerous cells are not able to recover from the damage. This results in a reduction or elimination of cancer. Radiation also affects healthy cells which can cause side effects. The side effects a patient experiences depends on the kind of radiotherapy they are having and the part of the body being treated.