Abstract
PET images provide heterogeneous metabolic information in precision radiation treatment planning and the radiation dose given to high metabolic volumes should be escalated. However, PET scanning will increase the radiation dose received by patients. The aim of this study was to evaluated the feasibility of automatic intratumor segmentation in CT of NSCLC patients based on level-set evolution and cell automaton algorithm and assess the consistency with PET metabolic subregions. The PET and plan-CT imaging data set of 17 patients who have diagnosed with NSCLC were randomly collected. First, the gross tumor volume (GTV) was defined using a threshold of 40% SUVmax on PET. Then, rigid registration was used to align PET images to plan-CT images and the GTV was mapped to the CT image subsequently. The subregions which describe heterogeneity of voxel gray-level intensities were then automatic segmented using an algorithm combined level-set evolution and cell automaton in GTVCT. Meanwhile, the three metabolic subregions in GTVPET were delineated using threshold interval a) 40%-60% SUVmax, b) 60%-80% SUVmax, and c) 80%-100% SUVmax. To evaluate the consistency with PET metabolic subregions, we calculated the spatial overlap by Dice’s similarity coefficient (DSC). In total, 21 GTV pairs acquired from CT and PET data set were used to evaluate the feasibility of method proposed in this study. The GTVCT was automatically divided into three heterogenous subregions based on its difference on grays-level intensities and regional connectivity of voxel and 63 subregions were acquired. The average DSC value calculated from subregion in CT and PET is 0.725 with interval (0.321,0.905). Our study revealed that there is a significant correlation between PET metabolic information and CT gray-level intensity. The automatic segmentation of subregion in CT images may can serve as an alternative to the metabolic region delineated in PET.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
