Investigation of a Dynamical kV Aperture together with Combined MV-kV Dose Planning for Implementing Real-time 3D MV-kV Prostate Motion Tracking

Abstract

In prostate cancer cases, there is no strong correlation between internal organ motion and externally visible motion, so optimal application of IGRT requires internal tracking techniques. Real-time 3D prostate tracking based on combined MV-kV imaging is an attractive solution since it uses the built-in hardware of modern LINACs equipped with OBI and EPID. However, continuous kV imaging throughout the treatment can lead to excess diagnostic dose exposure to the patient. To manage kV exposure, this work investigates the incorporation of the delivered kV tracking dose at the treatment planning stage through combined MV-kV beam modeling and conformal kV beam aperture shaping.