Medical Physics Seminar – Monday, November 10, 2014
Characterization of interplay errors in step-and-shoot IMRT of the lung
Travis McCaw (student of Dr. Larry DeWerd)
Research Assistant, Medical Radiation Research Center, Dept of Medical Physics, UW-School of Medicine & Public Health, Madison, WI - USA -
Task Group 76 of the AAPM provides recommendations for the use of respiratory motion management in radiation therapy; however, these recommendations are based exclusively on the amplitude of the motion. Delivery errors dependent on the frequency of respiratory motion have been observed in IMRT treatments due to interplay between the target motion and the fluence modulation. In this work, delivery errors in step-and-shoot IMRT were quantified using dose-volume metrics, with emphasis on the impact of low-frequency respiratory-motion components. The results of this work provide progress toward updated motion-management recommendations with consideration of both motion
amplitude and frequency.