Radiation therapy makes use of high energy waves to kill the potential cancer cells. Radiation therapy is also known as radiotherapy, x-ray therapy or irradiation which makes use of x-rays, gamma rays and charged particles to destroy cancer cells. Radiation therapy can be used alone to treat cancer or in combination with surgery or chemotherapy depending on the particular case. The radiation can be delivered through external-beam radiation therapy or internal radiation therapy. The radioactive materials that are used for treating cancer work through the entire body to kill the cancer cells. Radiation causes damage to DNA of potential cells and then the dead cells are drained out of body naturally.
There are medicines which help in making cancerous tissues sensitive to radiation and easily destroy them which are called radiosensitizers. Radiation therapy can be given in different ways and it is possible that sometimes oncologists use different types of radiation therapy for one patient. This is one of the most common cancer treatments as almost 50% of the patients undergo radiation therapy at least once during the whole treatment process. Before performing the radiation therapy, oncologists with their team plan specific type and amount of radiation to be given to the patient. Different doses of radiation are given to the patient depending on their condition. The dose of radiation is measured in gray unit (Gy).
Radiotherapy not only damages the cancer cells but also affects the normal cells which cause various side effects. Therefore, oncologists take care of different aspects such as where to focus the radiation and how much radiation can normal cells accept so as to minimize the damage to normal cells.
Radiation therapy can be used for curative purpose or as a palliative therapy to minimize the symptoms of cancer. As a palliative therapy, radiation can be used to shrink tumor pressing the spine, for brain or near the esophagus.
The organs which are most commonly affected by radiation are reproductive organs. The radiation is given to the affected area as well as the surrounding cells to avoid from spreading it. Radiation therapy cannot be performed on the same area if the maximum amount of radiation has already been given. However, a distant area of the body can be treated with radiation therapy.