Radiotherapy is used for a number of different medical purposes including:
● to cure an illness, for example by destroying a tumour (abnormal tissue),
● to control symptoms, such as relieving pain,
● before surgery, to shrink a tumour so that it is easier to remove, and
● after surgery, to destroy small amounts of tumour that may be left.
Radiotherapy is sometimes used in a process called total body irradiation (TBI).