PET/CT Rigid-Body Registration in Radiation Treatment Planning Settings: Phantom Validation and Strategy Investigation

摘要

Therapeutic outcomes from radiation treatment planning (RTP) may be improved by combining tumour metabolism data with anatomic location via PET/CT image fusion. The aim of this work is to reveal the spatial accuracy, re-producibility and speed of registration techniques used in Gemini PET/CT system as a part of quality assurance. A multi-layer alignment device and a Rando Man phantom were used to validate PET/CT intrinsic alignment. Known transformations were performed to simulate different misalignment between PET and CT phantom images. Point-based and image-based registration techniques used to correct misalignment were assessed and compared quantitatively by measuring absolute distances between the centroids of corresponding fiducial markers in the registered volumes. In comparison with phantom studies using image-based registration, point-based registration shows better spatial accuracy and faster correlation, but longer time and more effort in human intervention. The experimental findings confirm that Gemini can produce robust intrinsic image alignment, as well as the accurate PET/CT image registration with careful user interaction.