Computer simulations in radiation physics, biology and medicine

Computer simulation techniques play major roles in radiation physics, biology, and oncology, and recent advances in these areas have found diverse applications. Applications range from direct medical uses such as planning and simulating patients treated with external beams of radiation using computerized tomography to basic research modelling DNA molecular structures or gene activation and inactivation. Our ability to simulate and reconstruct patient anatomy has resulted in dynamic conformal therapy in which large accelerators are swept around patients to deliver the dose in complex tumour volumes while sparing sensitive normal tissues. Our ability to image the patient during treatment, to verify the area being treated, and to adjust the treatment in real time are in the development stage and are rapidly being applied to the clinic. Our ability to reconstruct complex structures of the human cell, the cell nucleus, and even DNA molecules has allowed us to simulate cell and genetic kinetics leading to better models describing the steps leading to cancer and genetic disorders as well as a better knowledge of how to modify these steps for therapeutic benefit. An overview of some of the most recent advances in radiation therapy and radiation biophysics will be presented.