The characterization of a promising new optical source for use with a radiotherapy treatment simulator.

We report on an experimental examination of a new powerful optical source with potential application in radiotherapy treatment simulation. The illuminance, effective source position, and source size have been measured for this new source and, for comparison, for conventional sources on a simulator and a linear accelerator. This new source is considerably brighter than those in common use in radiotherapy. Its effective optical source size is larger than that on the linear accelerator tested but comparable with that on a conventional simulator.