The use of an image processing system in radiotherapy simulation

Image quality produced in radiotherapy simulation is often so poor in certain anatomical sites (e.g. the pelvis) that it can adversely affect clinical judgement with regard to treatment set-up. In treatment planning both the field arrangement and the availability of accurate anatomical information are important, and should ideally be provided at the time of simulation by methods based on the principle of computerised tomography. In this work an image processing system has been used as a link between the video output from the simulator and the treatment planning computer in order to implement a CT facility on the simulator, as well as allowing real-time image enhancement to be investigated as a method of improving picture quality. This approach also enables a new method of simulation to be considered which reduces patient dose and prolongs the useful working life of the X-ray tube.