Room: Exhibit Hall | Forum 9
Purpose: To study the feasibility of defining the radiotherapy target of non-small cell lung cancer(NSCLC) applying the fourâ€”dimensional computed tomography (4DCT) and enhanced CT image deformation registration.
Methods: Ten NSCLC patients who accepted radiation therapy were selected in this study. The 4DCT in free breathing, enhanced CT in deep breathing were acquired sequentially.4DCT were sorted into ten series CT images to breath phase. MIM software was used for deformable image registration. Gross tumor volume(GTV) were contoured on different CT series and the IGTV was merged by ten phases GTVs. The Enhanced CT image was deformable registered to each phase of 4DCT images and acquired GTVDR. The IGTVDR was got by merging the 10 GTVsDR. The target volumes differences were compared by paired t-test.
Results: Overlapping index was 115.4Â±13.8%. The volumes of GTVs obtained from 4DCT images after DR increased by an average of 8.18ï¼…(Pï¼œ0.05) consistent with Enhanced CT image basic volume. The IGTVDR increased by an average of 9.67% (P=0.018) than IGTV.
Conclusion: Enhanced CT image can display more information than 4DCT and showed a higher contrast. When sketch the GTV, enhanced CT images should be combined with 4DCT image, the IGTV obtained bases on this can better determine the scope and the trajectory of the target, and improve the target delineation accuracy of NSCLC.
Not Applicable / None Entered.