脑胶质瘤表观扩散系数与肿瘤分级及IDH1突变的关系

Study of apparent diffusion coefficient and glioma grading and molecular IDH1 mutant

目的探讨MR扩散加权成像(diffusion weighted imaging,DWI)的表观扩散系数(apparent diffusion coefficient,ADC)在脑胶质瘤分级及分型中的意义,进一步探讨ADC与异柠檬酸脱氢酶-1(isocitrate dehydrogenase-1,IDH1)突变分型的相关性。方法收集首都医科大学宣武医院经病理证实的82例脑胶质瘤患者的影像资料,测量肿瘤实质区、对侧正常白质ADC值,并计算最小ADC值(minimum ADC,ADC min)、平均ADC值(mean ADC,ADC mean)、相对最小ADC值(relative minimum ADC,rADC min)、相对平均ADC值(relative mean ADC,rADC mean)值,探讨所有ADC值在各级别胶质瘤及亚型间的差异以及其与IDH1突变的关系。结果82例脑胶质瘤患者中2016世界卫生组织(World Health Organization,WHO)分级Ⅱ级27例、Ⅲ级22例、Ⅳ级33例,其中低级别27例、高级别55例;Ⅱ~Ⅲ级胶质瘤病理分型为星形细胞瘤(astrocytoma,AC)26例及少突胶质细胞瘤(oligodendroglioma,OD)23例。Ⅱ~Ⅲ级胶质瘤IDH1突变型(IDH1 mutant,IDH1 mut)28例、IDH1野生型(IDH1 wild-type,IDH1 wi ld)21例。肿瘤实质ADC min、ADC mean、rADC min、rADC mean在胶质瘤Ⅱ级与Ⅳ级、Ⅲ级与Ⅳ级之间差异均有统计学意义(P均<0.05),而在Ⅱ级与Ⅲ级之间差异无统计学意义(P>0.05);ADC min、ADC mean、rADC min、rADC mean在高低级别胶质瘤之间差异有统计学意义(P=0.023、0.029、0.024、0.035);ADC min、rADC min、rADC mean在AC及OD之间差异有统计学意义(P=0.044、0.025、0.040);ADC min、ADC mean、rADC min、rADC mean在IDH1 mut及IDH1 wi ld之间差异均无统计学意义(P>0.05)。结论术前ADC值有助于胶质瘤的分级及分型,但不能预估IDH1突变状态。

Objective To investigate the value of apparent diffusion coefficient(ADC)from diffusion weighted imaging(DWI)in determinate glioma grades and subtype,and investigate the correlation between ADC and isocitrate dehydrogenase-1(IDH 1)mutant.Methods We retrospectively analyzed 82 patients with glioma confirmed by postoperative pathology in our hospital.ADC values of the tumor parenchymal area and contralateral normal white matter were measured,and minimum ADC values,mean ADC values,relative minimum ADC values,relative mean ADC values were calculated.All ADC values in glioma at each grade and subtype were statistically compared.The correlation between all ADC values and IDH 1 mutation status were analyzed.Results There were 27 cases,22 cases and 33 cases of World Health Organization(WHO)Ⅱ,ⅢandⅣgrades glioma respectively,low-grade 27 cases and high-grade 55 cases.The pathology subtype ofⅡandⅢgrades glioma were astrocytoma and oligodendroglioma,astrocytoma 26 cases and oligodendroglioma 23 cases respectively.There were 28 cases of IDH 1 mut and 21 cases of IDH 1 wild in all theⅡandⅢgrades glioma.Minimum ADC(ADC min),mean ADC(ADC mean),relative minimum ADC(rADC min),relative mean ADC(rADC mean)between gradeⅡglioma group and gradeⅣglioma group,gradeⅢglioma group and gradeⅣglioma group were statistically significant(P<0.05),gradeⅡglioma group and gradeⅢglioma group were not statistically significant(P>0.05),All ADC values between high and low grade glioma were statistically significant(P=0.023,0.029,0.024,0.035).ADC min,rADC min,rADC mean between astrocytoma and oligodendroglioma were statistically significant(P=0.044,0.025,0.040).All ADC values between IDH 1 mut and IDH 1 wild were not statistically significant(P>0.05).Conclusions ADC values could be used to predict the preoperative pathological grade and subtype of glioma,however those couldn’t be used to predict the preoperative IDH 1 mutant.