Radiation Oncology is the treatment of cancer patients with high-energy ionizing radiation. Radiation is delivered in the form of x-rays, electrons or protons. Linear accelerators are used in radiation therapy to deliver radiation from an external source, whereas brachytherapy utilizes internal sources of radiation which emit gamma or beta particles.
The medical physicist is responsible for the safe and effective delivery of radiation to the cancer patient. This responsibility is carried out through the design and optimization of treatment plans and the evaluation of the treatment machines and sources. The medical physicist often acts as the radiation safety officer to ensure compliance with state and federal regulations.