ABSTRACT
Radiotherapy is an effective treatment for many types of cancer. It uses high energy X-rays to kill off cancer cells. However, these also damage normal cells so the aim in radiotherapy is to get maximum radiation to cancer cells without too much damage to normal ones. Normal cells reproduce in response to the death of other cells, thus maintaining a constant number of cells in the body. Cells divide at different rates. Cells such as cancer cells that have rapid rates of cell division are more sensitive to radiation. Radiotherapy is usually given on an outpatient basis. External beam therapy from a machine called a linear accelerator sends a carefully directed beam of X-rays to the tumour area. The reactions or side effects to radiotherapy are relative to the site being treated. A patient having radiotherapy to the rectum may experience some diarrhoea. The most common side effects of radiotherapy are tiredness and fatigue.
