Radiation therapy is often used to treat patients with cancer. In contrast to chemotherapy it is a local treatment only and is used to treat disease that is localised to a specific area. Radiation therapy is delivered using photons which are 'packet of energy'.
This energy is deposited in cells and causes the cells to die. Radiation kills both normal and cancer cells but normal cells are better able to recover than cancer cells and therefore there is a therapeutic advantage. Radiation therapy is normally delivered over a protracted period of time to allow the normal cells to recover.
Treatment is usually given Monday to Friday and often takes 6 or more weeks to deliver. Delivering the dose in small doses or fractions allows us to give a higher dose without causing severe side effects or long term damage. This higher dose is often effective in eliminating all the cancer cells leading to remission or cure.