The external beam radiotherapy’s high-energy X-ray beams damage the cancer cells and stop them from growing and spreading to other parts of the body.
Radiotherapy permanently damages and kills the cancer cells, but healthy cells can repair themselves and recover more easily.
The radiotherapy machine does not usually touch you. Treatment usually only takes a few minutes and is not painful.
This treatment is normally given as a number of short, daily treatments in a radiotherapy department. These are called treatment sessions or fractions.
It is given using a machine that looks like a large x-ray machine.
You usually have radiotherapy as an outpatient, but it is sometimes given as an inpatient if you are feeling unwell.
The number of treatment sessions you have will depend on the type of cancer you have and the aim of the treatment.