Differential Diagnosis Of Radiation Necrosis And Recurrence Of Glioma By Multimodal MRI

Objectives By analyzing the imaging manifestations of multimodal magnetic resonance imaging(MRI)in patients with glioma radiation necrosis and tumor recurrence,the value of multimodal MRI in the diagnosis of glioma radiation necrosis and tumor recurrence was discussed.It also provide more accurate diagnostic basis for radiation necrosis and postoperative recurrence in glioma patients.Methods Patients with radiation necrosis or recurrence of gliomas confirmed by secondary surgical pathology and follow-up study after receiving proton therapy in Zibo Bashan Wanjie Hospital from January 2016 to September 2021 were selected as the research subjects.A total of 122 patients were included in the study.After the second surgery histopathological diagnosis or imaging follow-up,they were divided into glioma recurrence group and radiation necrosis group,including 70 patients with glioma recurrence and 52 patients with radiation necrosis,and MRI scan,contrast-enhanced MRI,PWI examination and MRS examination were performed on the patients respectively.Among them,PWI examination uses hemodynamic indicators(r CBV value,r CBF value,r MTT value)compared with the contrast-enhanced area and the contralateral normal white matter;MRS examination indicators are the ratios of common metabolites(Cho/NAA,Cho/Cr and Cr/NAA)).By comparing and analyzing the different imaging findings of patients with radiation necrosis and tumor recurrence,and also by drawing receiver operating characteristic(ROC)curves and establishing multiple linear regression models,we can find out the differential diagnostic value in analysis of multimodal MRI imaging in glioma radiation necrosis and tumor recurrence.Results 1.MRI plain scan and contrast-enhanced MRI scan:plain scan showed low signal on T1WI,high signal on T2WI,with surrounding edema;contrast-enhanced MRI scan showed that lesions in the glioma recurrence group were mostly irregular rings or masses,or modular enhancement,or new lesion enhancement appeared outside tumor area.The lesions in the radiation necrosis group showed irregular rosette enhancement;2.PWI examination:The r CBV,r CBF and r MTT parameters in the recurrence group were higher than those in the radiation necrosis group(P<0.05).The Youden index of r CBV,r CBF and r MTT in the differential diagnosis of glioma recurrence and radiation necrosis were 0.829,0.691,and 0.512,respectively.AUC values were 0.978,0.921,and 0.802,respectively.Among them,the r CBV parameter had the highest diagnostic AUC value and Youden index,and the diagnostic sensitivity and specificity were 82.9%and 100%,respectively;3.MRS examination:Cr/NAA,Cho/Cr and Cho/NAA were higher than those in the radiation necrosis group(P<0.05),and each MRS parameter of Cr/NAA,Cho/Cr and Cho/NAA differential diagnose the Youden index of glioma recurrence and radiation necrosis were0.617,0.738,0.781,and the AUC values were 0.800,0.894,and 0.934,respectively.Among them,Cho/NAA had the largest AUC value and Youden index,and its diagnostic sensitivity and specificity were 80.0%and 98.1%,respectively;4.Multiple Linear regression analysis:In order to reasonably select the imaging indicators for differential diagnosis of multimodal MRI imaging in glioma recurrence and radiation necrosis,glioma recurrence and radiation necrosis were used as dependent variables,r CBV,r CBF,r MTT,Cr/NAA,Cho/Cr and Cho/NAA were used as independent variables to establish a linear regression.Through the model summary and model test of the linear regression,R~2>0.6accorded with the multiple regression.Because the r CBV,r CBF,r MTT of PWI and Cho/NAA,Cho/Cr,Cr/NAA of MRS and other indicators are not completely independent of each other in their respective inspection items,and there is mutual influence,thestepwise regression method is specially used for analysis.r CBV,r CBF,r MTT,Cho/NAA,Cho/Cr,Cr/NAA were substituted with original values for linear analysis,and the results showed that r CBV,r CBF,Cho/NAA met the requirements(P<0.05);5.Multimodal MRI:Combined with the linear regression model and the Youden index of the respective indicators,r CBV and Cho/NAA were selected as the multimodal inspection indicators.The ROC curve was drawn and it was found that the AUC value of multimodal MRI in the diagnosis of glioma recurrence and radiation necrosis was 0.962.By comparing the diagnostic values of various parameters,it was found that the sensitivity of multimodal MRI diagnosis was 94.3%,which was significantly higher than r CBV(82.9%)and Cho/NAA(80.0%),the diagnostic accuracy of multimodal MRI was 97.5%,which was significantly higher than r CBV(91.5%)and Cho/NAA(89.2%)(P<0.05).Conclusions Both PWI and MRS examinations can effectively achieve the early identification of radiation necrosis and tumor recurrence in gliomas.Through the step-by-step analysis,it can be seen that r CBV,Cho/NAA and r CBF are meaningful for differential diagnosis.Compared with individual examination,multimodal MRI of r CBV parameters in PWI and Cho/NAA parameters in MRS can significantly improve the sensitivity and accuracy of differential diagnosis of glioma radiation necrosis and tumor recurrence.And this definately should be widely used and promoted in clinical practice.Figure 5;Table 15;Reference 124...