Preliminary Exploration Of DTI Technique For Target Recognition Of High-grade Gliomas

Objective:To explore the application of DTI?diffusion tensor imaging?technique in delineating the target area of high-grade glioma.Methods:Patients admitted to the radiotherapy department of our hospital from January 2018 to January 2020 after total resection of high-grade glioma were collected.A total of 30 patients with advanced gliomas were collected,including 15 patients with grade III gliomas?grade III group?and 15patients with grade IV gliomas?grade IV group?.All patients received DTI examination before radiotherapy.ADC mean value,minimum value,maximum value,FA mean value,minimum value and maximum value of peritumoral area,proximal tumor area,medium tumor area,distal tumor area,peripheral tumor area and contralateral normal brain tissue area were measured respectively after DTI image processing.And the data was statistically analyzed to analyze its correlation with tumor invasion range.Results:1. The change trend of ADC value and FA value in different regions of high-grade glioma in grade III group,grade IV group and the whole group. The trend of ADC value in the grade III group was firstly increased and then decreased from peritumoral area to contralateral normal brain tissue area.The peak value of ADC in the grade III group was in the proximal tumor increased and then decreased from peritumoral area to contralateral normal brain tissue area.The peak value of ADC in the four-grade glioma group was high-grade gliomas was firstly increased and then decreased from peritumoral area to contralateral normal brain tissue area.The peak value of ADCmean?ADCmin in the four-grade glioma group was in proximal tumor of ADCmax in the four-grade glioma group was in proximal tumor area(ADCmax=971×10^-6mm²/s).The FA value continued to increase from peritumoral area to peripheral tumor area.2. Comparison of the values of ADCmean and FAmean in the peritumor regions and the contralateral normal brain tissues of the grade III group,grade IV group and the whole group.The ADCmean values of the peripheral tumor region,the proximal tumor region,the middle tumor region and the distal tumor region of the grade III group were all higher than the area of the contralateral normal brain tissue,with statistically significant differences?P<0.05?.The peripheral tumor region was higher than the area of the contralateral normal brain tissue,but there was no statistical difference?P=0.424?.The FAmean values of the peritumor region,the near-tumor region and the medium tumor region were all lower than that of the contralateral normal brain tissue region,with statistically significant differences?P<0.05?.The distal tumor region was lower than that of the contralateral normal brain tissue region,and the peritumor region was higher than that of the contralateral normal brain tissue region,but there was no statistical difference?P=0.095,P=0.114?.In the grade IV group,the ADCmean values in the near-tumor region,the mid-tumor region,the far-tumor region and the peri-tumor region were all higher than that in the contralateral normal brain tissue region,with statistically significant differences?P<0.05?.The ADCmean values in the peri-tumor region were higher than that in the contralateral normal brain tissue region,with no statistical difference?P=0.514?.The FAmean values in the peritumor region,the near-tumor region and the medium tumor region were all lower than that in the contralateral normal brain tissue region,and the differences were statistically significant?P<0.05?.The distal tumor region was lower than that in the contralateral normal brain tissue region,and the peritumor region was higher than that in the contralateral normal brain tissue region,but there was no statistical difference?P=0.245,P=0.378?.In the whole group,the ADCmean values of the peripheral tumor area,the near-tumor area,the middle tumor area and the distant tumor area were all higher than the area of the contralateral normal brain tissue,and the differences were statistically significant?P<0.05?.The peripheral tumor area was higher than the area of the contralateral normal brain tissue,but there was no statistical difference?P=0.073?.The FAmean values of the peritumor region,the near-tumor region and the medium tumor region were all lower than that of the contralateral normal brain tissue region,and the differences were statistically significant?P<0.05?.The distal tumor region was lower than that of the contralateral normal brain tissue region,and the peritumor region was higher than that of the contralateral normal brain tissue region,but there was no statistical difference?P=0.053,P=0.066?.3. Comparison of ADC values and FA values between the III group and IV group in the same area around tumor.The ADCmean?ADC min?ADC ADCmax=847×10^-6mm²/s),the difference was statistically significant?P<0.05?.The ADCmean and ADCmax of the grade III group in the proximal tumor area were higher than that of the grade IV group,with statistically significant differences?P<0.05?,while the ADCmin was lower than that of the grade IV group,with no statistically significant differences?P=0.34?.The ADCmean,ADCmin and ADCmax in medium tumor area of the grade III group were all lower than those of the grade IV group,with statistically significant differences?P<0.05?.The ADCmean and ADCmin of the distant tumor region grade III group were lower than that of the grade IV group,and the differences were statistically significant?P<0.05?,while the ADCmax was lower than that of the grade IV group,but there was no statistical difference?P=0.06?.The ADCmean,ADCmin and ADCmax of the grade III group were all lower than those of the grade IV group in peripheral tumor area,and there was no statistical difference?P>0.05?.Conclusion:1.ADC and FA values can reflect the infiltration degree and range of tumor cells in high-grade glioma,which can be used to guide the delineation of clinical target area.However,the relationship between tumor invasion degree and recurrence risk needs to be further analyzed to determine the critical value of ADC and FA values so as to define the boundary of target area.2.The peak value of ADC in the grade III group was in the proximal tumor area.The peak value of ADC in the grade IV group was in medium tumor area.The malignant degree of IV grade glioma is higher than III grade glioma,and tumor cell infiltration of IV grade glioma is wider than III grade glioma.It is necessary to expand the target area to reduce the recurrence of the tumor.