Cancer is a condition characterised by uncontrolled growth of abnormal cells inside the body. These cells, if left to grow inside the body, rapidly destroy the normal healthy cells thereby hindering normal body functioning. Radiation therapy is a type of cancer treatment, which makes use of a high-energy radiation beam to kill cancer cells by damaging their DNA. When the DNA is damaged, the cancer cells are unable to multiple, thus they die, are broken down and removed from the body. This enables the patient to live a longer healthy life.