Registration of tomotherapy animal study data

Until recently, post optimization concepts underlying tomotherapy have been tested experimentally only on inanimate phantoms. New experimental data, from a canine head, has provided data structures similar to humane. Here, the authors report the initial test results from registration of 11 sinograms. This data has experimental offsets in (x,y,z) and roll. Since it is known from earlier studies that simultaneous offsets in z and roll present one of the greatest challenges to the algorithm, these offsets were emphasized. Although, only four parameters were varied the algorithm computes results for all six possible offsets-(x,y,z), (pitch,yaw,roll). Standard deviations of the differences between experimental and algorithmic values were computed for each offset. The largest a's were 0.3 mm and 0.1 degree that are small in comparison with the specifications of /spl plusmn/2 mm and /spl plusmn/2 degrees. The algorithm is now in the prototyping stage. Several enhancements are under study prior to release of version one. This data will provide a realistic test for these enhancements.