Click here to


Are you sure ?

Yes, do it No, cancel

Study the Feasibility of Defining the Individual Internal Gross Tumor Volume (IGTV) of Hepatocellular Carcinoma Using 4DCT and MRI-T2 Images by Deformable Registration

C Ma*, Shandong Cancer Hospital and Institute, Jinan, Shandong Province


(Tuesday, 7/31/2018) 3:45 PM - 4:15 PM

Room: Exhibit Hall | Forum 8

Purpose: To study the feasibility of defining the individual internal gross tumor volume (IGTV) of hepatocellular carcinoma (HCC) using four-dimensional computed tomography (4DCT) imaging and T2-weighted Magnetic Resonance Imaging (MRI-T2) by deformable registration.

Methods: Ten HCC patients who previously received radiotherapy treatment were selected for this study. The following simulation images were acquired sequentially: 4DCT in free breathing and MRI-T2 in deep-inspiration breath holding. All 4DCT images were sorted into ten phases according to breath cycle (CT00–CT90). The accuracy of DR was assessed by three methods; the maximum displacement on three dimensional directions of portal vein, the maximum displacement on three dimensional directions of the celiac trunk, and the ratio of liver overlap (P-LIVER). Gross tumor volumes (GTVs) were contoured on all CT images and the IGTV obtained by merging the GTVs in each phase of 4DCT imaging. The GTV on the MRI-T2 image was deformably registered to each 4DCT phase image using MIM software version 6.5.6 and the results labeled as –DR. The IGTVDR was obtained by merging the GTVDR on the 4DCT images. Statistical differences in the GTVs and between the IGTV and IGTVDR were assessed by a paired t-test.

Results: The P-LIVER was 115.4±13.8%. Then the Reg Reveal and Reg Refine were used to minmize the registration error manually. The edge of most lesions could be definitively identified using MRI-T2 images compared to 4DCT images. The GTVs after DR on 4DCT different phase imaging increased by an average of 8.18% (P<0.05), whilst the volume of IGTVDR increased by an average of 9.67% compared to that of IGTV (P<0.05).

Conclusion: The use of 4DCT imaging alone has the potential risk of missing a partial volume of the HCC. However, MRI-T2 images can carry more information than 4DCT image. As such, the combination of 4DCT and MRI-T2 images using the DR technique may improve accuracy in the delineation of HCC.




Not Applicable / None Entered.

Contact Email