RadiotherapyRadiotherapy is the use of radiation to treat cancer. The radiotherapy is targeted at the part of your body where the cancer has been found. Your care will be adapted to meet your individual needs and may differ from what is described here. So, it's important that you follow your doctor's advice. The aim of the treatment is to destroy the cancer cells in the area being treated. Normal cells will also be affected but they are better able to repair themselves Why have radiotherapy?Radiotherapy can be used to treat many different types of cancer. Radiotherapy works by attacking cells that are dividing rapidly, such as cancer cells.