When using radiation therapy, the cancer is treated by high-energy radiation beams that are delivered from a machine called a linear accelerator. As the radiation beams are directed to the cancer area, they produce high-energy x-rays. While the radiation treatment is in progress it will detect only the specific area where the cancer is located and will not travel to any other part of your body. The radiation oncologist will carefully tailor the radiation beam to the area of treatment delivering high doses to the tumor and excluding normal structures. Normally, radiation therapy treatments are usually done on an outpatient basis with treatment occurring once a day, five days per week, for six to eight weeks. The goal of radiation therapy is to destroy the cancer with as little injury as possible to the surrounding normal tissues.
Curative Radiotherapy: The main purpose for using radiation treatment is to cure the patient of cancer by eliminating every single cancer cell or preventing them from spreading through the body. When the goal is to cure the cancer, high doses are often required.
Palliative Radiotherapy: In a situation where eliminating the cancer cells may not be possible, radiotherapy may be used to relieve cancer symptoms. Palliative radiotherapy may be given to relieve pain due to bone invasion, headaches due to brain metastasis, paralysis due to spinal cord compression, to reduce pressure or stop bleeding due to cancer involvement. Many patients find the quality of their lives improved with radiation therapy. Palliative radiation therapy usually requires fewer treatments than curative radiation therapy because not all of the cancer cells have to be removed to relieve the symptoms.