Radiation oncologist use radiation to treat cancer. Radiation has the ability to treat benign tumors and some benign diseases. This type of physician is involved in the treatment of a cancer patient, but is not the only one involved. A physician in this specialty may work on a “cancer team” to ensure the correct treatment and plan for a patient facing this illness. Radiation may be given alone as treatment or may also be given with other types of treatment depending on the patient. X-rays for example are done by a radiation oncologist on a cancer patient as well.