Synthetic MRI-aided Pelvic Multi-organ Segmentation in Cone-beam Computed Tomography

摘要

CBCT-guided adaptive prostate radiotherapy requires the accurate and rapid segmentation of the prostate and organs-at-risk from on-board CBCT images. Automatic segmentation based solely on CBCT can eliminate the need for registration to the planning CT, but has not been widely studied. Soft tissue contrast, such as prostate, is poor on CBCT images, which is often further degraded by CBCT artifacts. In this study, a new segmentation strategy is proposed for pelvic multi-organ segmentation aided by CBCT-based synthetic MRI. We tested our proposed method using 20 prostate cancer patients' who underwent radiotherapy. The mean Dice similarity coefficient (DSC) of bladder, prostate and rectum were 95%, 86%, and 91%, which demonstrated the detection and segmentation accuracy of the proposed method. Methods for the accurate and fast segmentation of the prostate, bladder and rectum warrants further development in support a CBCT-guided adaptive radiotherapy workflow for prostate cancer.