Application of CT/MR image fusing in gross tumor volume delineation of esophageal squamous cell carcinoma

Abstract

Objective To investigate the application value of CT/MR image fusing in gross tumor volume (GTV) delineation of esophageal squamous cell carcinoma.Methods Twenty-nine patients with esophageal squamous cell carcinoma to be treated with radical surgery underwent routine CT scanning,MR T2-weighted imaging (T2WI) and diffusion weighted imaging (DWI) before surgery.Diffusion-sensitive gradient b values were taken at 400,600,and 800 s/mm2.GTVs were delineated on the CT image,CT/ MR T2WI,and CT/MR DWI respectively.The MR T2W1 image was used as the intermediary for the fusion of the CT image and MR DWI image.The length of GTVs measured under different imaging conditions were compared with the length of the resected specimen of esophagus.Results The GTV length was (44.94 ± 18.46) and (45.05 ±21.47) mm on the CT images and CT/MR T2WI images respectively.When the b values were 400,600,and 800 s/mm2,the esophageal carcinoma GTV length on CT/MR DWI images was (42.12 ± 17.79),(41.18 ± 17.17) and (39.77 ± 17.66) mm,respectively.The coefficient between the esophageal carcinoma GTV lengths on CT/MR DWI images and the pathological lesion lengths was 0.928,0.926 and 0.927 respectively.Conclusions CT/MR DWI images displays esophageal carcinoma GTV length more accurately,thus guiding the delineation of GTV effectively. Key words: Target delineation; Esophageal neoplasm; Diffusion-weighted magnetic resonance imaging; Image fusion