Medical Physics Seminar – Thursday, June 16, 2011
Small Field Dosimetry for an Output-Stabilized TomoTherapy Hi-Art Machine
Brian Hundertmark (student of Dr. T. Rockwell Mackie)
Research Assistant, Department of Medical Physics, UW-School of Medicine & Public Health, Madison, WI USA
Location: 335 (HSLC) Health Sciences Learning Center, 750 Highland Avenue, Madison, WI 53705
The TomoTherapy Hi-Art machine is a linear accelerator-based intensity-modulated radiotherapy [IMRT] treatment modality capable of delivering highly conformal dose distributions. Delivery outcomes are predicted by the Hi-Art s integrated treatement planning system [TPS] using complex beam models and dose calculation algorithms. The accuracy the preduction outcomes computed by the TPS is contingent on how well the beam models characterize the operating parameters of the HiArt machine [dose rate output, field size, etc]. Methods aimed to improve the accuracy of the measurements used to validate small-field TomoTherapy beam models and to reduce fluctuations in the Hi-Art s dose rate output are presented.