A helical tomotherapy dynamic quality assurance.

A multifaceted tomotherapy quality assurance procedure has been developed. This procedure tests most of the features inherent in the tomotherapy Hi-Art device. This includes the megavoltage imaging quality, spatial and temporal accuracy of the dynamic delivery properties, as well as more traditional beam output characteristics. This is accomplished with a specialized multichannel electrometer that measures collected charge every 100 ms and a Virtual Water cylindrical phantom that holds many ion chambers and differing density insert plugs. Both devices are offered with the Hi-Art product. These tests are presented as well as their sensitivity to beam and delivery variations.