Onboard CBCT integrated with Linac is now available for patient set up and therapeutic guidance. For these volumetric CBCTs to realize their full potential and enjoy broad clinical acceptance, the scatter must be removed and imaging dose must be significantly reduced while maintaining the advantages of conventional CT. This study will enhance understanding of noise and scatter behaviors in CBCT and gain useful knowledge on how to effectively remove the undesirable signals while reserving the edge information. The approach proposed has the potential to significantly change the way clinical systems are designed today, and could facilitate the design and translation into the clinic of new, large volume CT imaging systems. This research should lead to a significant advance in CBCT to fully realize the technical capacity of volumetric imaging. The methodology and techniques developed by this study may also be applicable for solving similar problems in other related bioengineering fields. Successful completion of this project will provide radiation oncology and related fields needed high quality volumetric imaging with reduced patient radiation dose. The proposed technique will allow physicians to better see the patient anatomy especially the low contrast tissues and more accurately define the tumor target volume. The improved image quality will also make it possible to use CBCT for accurate dose calculation and dose reconstruction. This will lay the foundation for next generation of adaptive therapy to optimally compensate for the patient setup error and inter-fractional anatomy change.
