Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A radiation oncologist is a doctor who specializes in the treatment of cancer patients, using radiation therapy as the main modality of treatment. Radiation can be given as a curative modality, either alone or in combination with surgery and/or chemotherapy. It may also be used palliatively, to relieve symptoms in patients with incurable cancers. In some countries (not the United States), radiotherapy and chemotherapy are controlled by a single oncologist who is a "clinical oncologist". Radiation oncologists work closely with other physicians such as surgical oncologists, other surgeons, internal medicine subspecialists and medical oncologists, as part of the multi-disciplinary cancer team.