These are specialist doctors who use ionizing radiation in the treatment of cancer. In other words they are a subset of oncologists. There are other types like medical oncologists and surgical oncologists. These define the different ways in the treatment of cancer. Radiation is given to cancer patients as a curative modality to burn the cancer cells either by itself or at times radiation is given along with surgical removal, and at other times radiation is also given as a palliative care to alleviate the symptoms. It is the role of radiation oncologists to determine how much of it, how frequently and where exactly should the radiation therapy be given and based on the radiation oncologist’s prescription the radiotherapist implements the radiation therapy.