Application of a Combination Method of Atlas-Based and Model-Based Auto-Segmentation in Thorax-And-Abdomen Cancer
XQ Jiang*, QF Jiang, T Li, JH Xiao, RM Zhong, GJ Li, S Bai, Department of Radiation Oncology, Chengdu, SichuanSU-E-J-101 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Atlas-based auto-segmentation and model-based auto-segmentation were combined to improve accuracy of auto-segmentation for thorax₋and₋abdomen cancer patient,herein referred to as A&M method. The purposes of this study were to evaluation the performance of A&M method and try to establish auto-segmentation application protocol in clinical.
Two major steps were performed in A&M method. Firstly, planning images and corresponding normal organ contours from 10 thorax-and-abdomen patients were selected as atlases input for ABAS. Auto-segmentation was performed on planning images of 20 thorax-and-abdomen new patients using ABAS software. Secondly, results from ABAS were adjusted using MBS software based on characteristic values of each organ. All operations were automatic running by using pre-edited scripting programs. Physicians reviewed the final A&M results and made necessary modifications.
The Dice Similarity Coefficient (DSC), that between contours generated by A&M auto-segmentation method and modified contours, was used to evaluate accuracy of A&M auto-segmentation. It also was used to compare with the DSC between contours generated by ABAS only and physicians modified results based on A&M contours.
Compared to physicians modified results based on A&M contours, the mean DSC to right Lung, left Lung, Heart, Liver, right Kidney, left Kidney, Spleen, with respect to the A&M auto-segmentation and the ABAS auto-segmentation were 0.95 vs. 0.96 (p=0.11); 0.95 vs. 0.96 (p=0.42); 0.93 vs. 0.91 (p<0.01); 0.95 vs. 0.93 (p<0.001);and 0.93 vs. 0.88 (p<0.01);0.95 vs. 0.89 (p<0.01), 0.86 vs. 0.80 (p<0.001), respectively. Auto-segmentation of all OARs using A&M method took about 12 minutes per patient in total, including ABAS 10 minutes and MBS 2 minutes.
Our results demonstrated the AM method can significantly improve the results from ABAS only for most normal organs in thorax₋and₋abdomen cancer patients. And the AM method is more convention and accurate than MBS method only in clinical applications.