Radiotherapy involves subjecting the affected cancerous growth to radiations. It works by destroying the cancer cells. It may be noted that the radiotherapy may destroy the normal cells around the affected ones. This can cause some side effects. However, there need not be any worry. The normal cells can repair thenselves, but cancerous cells are not capable of repairing themselves.
Radiotherapy can be both internal or external. External therapy is given by aiming high energy radio waves over the affected area using larger machines. Internal radiotherapy aims to treat the internal organs affected by the cancerous growth. It works by the radio active material placed inside the body.