Therapeutic radiological physics is the branch of physics as applied to radiation therapy. Therapeutic radiological physics involves the understanding of the radiation sources, types, and characteristics of radiation, interaction of radiation with matter, and thereafter the deposition of energy in matter. In clinical practice, therapeutic radiological physics deals with the technical tasks of preparing a patient to undergo radiation therapy. These tasks include simulation, patient data acquisition, individualized planning, verification, and dose delivery. The role of a therapeutic radiological physicist is to manage the technical aspects of patient care: providing technical expertise to the development of the institution, recommending and introducing new treatment techniques, and ensuring that all patients undergoing radiation therapy receive the best standard of care.