Application Value Of CT/MRI Image Fusion In The Treatment Of Primary Hepatocellular Carcinoma With ¹²⁵I Seed Implantation

Objective:To explore the application value of CT/MRI image fusion in the treatment of primary hepatocellular carcinoma with ¹²⁵I seed implantation by analyzing the CT/MRI image fusion utilization in tumor volume delineation and its influence on ¹²⁵I seed therapy plan.Methods:14 patients with primary hepatocellular carcinoma admitted from September 2013 to November 2018,with a total of 18 lesions.The examination of liver enhanced CT and enhanced MRI was performed before¹²⁵I seed implantation for all patients,which had complete clinical data and pathological diagnosis.The enhanced CT and MRI images were transmitted to a computerized three-dimensional treatment planning system?TPS?,and then the fusion of the CT and MRI images was performed by the method of deformation registration.The gross tumor volumes?GTV?and clinical target volumes?CTV?of CT(GTV_CT?CTV_CT)and CT/MRI(GTV_CT/MRI?CTV_CT/MRI)were delineated on CT and CT/MRI fusion images,respectively.A preoperative plan was made on the CT/MRI fusion image,and then was imported into the CT image to calculate the D90_CT?D90_CT/MRI and V90_CT?V90_CT/MRI of the CT/MRI fusion group and the CT group.The differences between CTV_CT/MRI and CTV_CT?GTV_CT/MR and GTV_CT?D90_CT/MRI and D90_CT?V90_CT/MRI and V90_CT on CT/MRI and CT images were compared.The therapeutic efficacy and local control rate were evaluated at 2 months.Results:A total of 18 lesions in 14 patients showed clear on CT and MRI images,and the fusion effect of CT/MRI images was satisfactory.The GTV_CT/MRI and GTV_CT of 18 lesions was?42.93±22.61?cm³ and?37.85±20.89?cm³,respectively,the difference of GTV was statistically significant between CT/MRI fusion images and CT images?t=7.538,P<0.05?.GTV_CT/MRI was larger than GTV_CT?12.46±5.05?%.The CTV_CT/MRI and CTV_CT was?58.11±29.34?cm³ and?52.14±26.95?cm³,respectively,the difference was statistically significant?t=6.862,P<0.05?.CTV_CT/MRI was larger than CTV_CT?11.27±5.03?%.The D90_CTT and D90_CT/MRI was?86.00±20.10?Gy and?95.02±20.26?Gy,respectively,and the difference was statistically significant?t=-6.091,P<0.05?.The V90_CT/MRI and V90_CT was 92.70%?88.55%,95.48%?and 94.85%?93.88%,98.40%?,respectively,and the difference was statistically significant?z=-3.724,P<0.05?.Two months after ¹²⁵I seed implantation,the efficacy of 14 patients with primary hepatocellular carcinoma was evaluated as complete response?CR?7.1%?1/14?,partial response?PR?28.6%?4/14?,stable disease?SD?57.1%?8/14?and progression?PD?7.1%?1/14?.The total effective rate was 35.7%,and the local control rate was 92.9%.Conclusions:1.For primary hepatocellular carcinoma patients treated with ¹²⁵I seed implantation,CT/MRI image fusion can increase the irradiation volume of the target area to some extent and reduce the occurrence of missed irradiation in the target area.2.¹²⁵I seed implantation can achieve better dose distribution for the treatment of primary hepatocellular carcinoma using CT/MRI image fusion guided preoperative target area delineation.3.For patients with primary hepatocellular carcinoma who have progressed after multiple treatments,¹²⁵I seed implantation is alternative.