论文部分内容阅读
目的 评估11 C-蛋氨酸PET/CT显像半定量参数对幕上胶质瘤术后MRI疑诊复发患者的诊断价值.方法 回顾性分析2015年6月至2017年6月于北京天坛医院行11C-蛋氨酸PET/CT显像的164例幕上胶质瘤术后患者(男107例,女57例;年龄6～74岁;高级别胶质瘤94例、低级别胶质瘤63例、分级不详7例)的资料,同期MRI均疑诊肿瘤复发且随访至少6个月.以病理或临床随访结果为诊断标准,计算并比较病灶11C-蛋氨酸摄取的半定量参数:最大标准摄取值(SUVmax)、平均标准摄取值(SUVmean)、病灶-本底SUVmax比值(TBRmax)、病灶-本底SUVmean比值(TBRmean).采用两独立样本t检验分析数据.绘制受试者工作特征(ROC)曲线并比较曲线下面积(AUC),选取上述指标最佳阈值计算诊断灵敏度和特异性.结果 共139例临床诊断为复发,25例临床诊断为未复发.复发组SUVmax、SUVmean、TBRmax和TBRmean均较未复发组增高(4.19±1.95与2.59±1.18、2.34±1.08与1.46±0.72、2.95±1.17与1.83±0.79、2.64±1.11与1.59±0.71;t值:5.126～6.183,均P＜0.01),但4个指标诊断复发的ROC AUC差异无统计学意义(z值:0.265～ 1.674,均P＞0.05),最佳阈值分别为3.05、1.65、1.96、1.79时,对应的灵敏度、特异性分别为67.6％(94/139)、100％(25/25),67.6％(94/139)、100％(25/25),79.9％(111/139)、100％(25/25),74.8％ (104/139)、100％(25/25).高级别胶质瘤中,复发组(81例)的半定量参数均高于未复发组(13例;t值:5.137～5.871,均P＜0.01);TBRmean的AUC大于SUVmean的AUC(0.858和0.802;z=1.982,P＜0.05).低级别胶质瘤中,复发组(54例)的半定量参数均高于未复发组(9例;t值:2.730～7.009,均P＜0.01),但4个指标的AUC无明显差异(z=0.444～1.407,均P＞0.05).37例有病理诊断且分级明确的复发患者中,高与低级别胶质瘤组半定量参数及其AUC未见明显差异(t值:1.387～ 1.937,z值:0.106～ 1.752,均P＞0.05).结论 11C-蛋氨酸PET/CT显像的半定量参数对MRI疑诊复发的幕上胶质瘤术后患者有一定的诊断价值,但对胶质瘤的分级鉴别价值有限;TBRmean诊断高级别胶质瘤术后复发较SUVmean更有优势.“,”Objective To assess the diagnostic values of 11C-methionine (MET) PET/CT semiquantitative parameters for detecting recurrence in patients who were diagnosed with suspicious recurrence by MRI after resection of supratentorial gliomas.Methods A total of 164 patients (107 males,57 females,age 6-74 years;high-grade 94,low-grade 63,unclear 7) with supratentorial gliomas who underwent 11C-MET PET/CT between June 2015 and June 2017 in Beijing Tiantan Hospital were enrolled respectively.All patients were with suspicious recurrence after surgery showed by MRI and followed up for 6 months at least.The final diagnosis was determined with histopathological analysis or clinical follow-up.The maximum and mean standardized uptake value (SUVmax and SUVmean),tumor-to-background ratios (TBR) of SUVmax and SUVmean(TBRmax and TBRmean) were recorded and compared between patients with recurrence or without recurrence using independent-sample t test.Receiver operating characteristic (ROC) curves were drawn to determine the threshold,and the diagnostic sensitivity and specificity of each parameter were calculated.Results According to the clinical diagnosis,there were 139 patients with recurrence and 25 without recurrence.SUVmax,SUVmean,TBRmax and TBRmean were significantly higher for patients with recurrence than those without recurrence (4.19±1.95 vs 2.59±1.18,2.34±1.08 vs 1.46±0.72,2.95±1.17 vs 1.83±0.79,2.64±1.11 vs 1.59±0.71;t values:5.126-6.183,all P＜0.01),but there was no difference in the areas under the ROC curve (AUC) for diagnosis of recurrence with the 4 parameters (z values:0.265-1.674,all P＞0.05),for which the optimal cut-off values were 3.05,1.65,1.96 and 1.79,respectively,and the corresponding sensitivities/specificities for the diagnosis of recurrence were 67.6％ (94/139) / 100％ (25/25),67.6％ (94/139)/100％(25/25),79.9％(111/139)/100％(25/25),74.8％(104/139)/100％ (25/25),respectively.Patients with (n=81) or without (n=13) recurrence had different semiquantitative parameters in high-grade glioma group (t values:5.137-5.871,all P＜0.01),and the AUC for TBRmean was greater than that for SUVmean(0.858 vs 0.802;z=1.982,P＜0.05).Patients with (n=54) or without (n=9) recurrence in low-grade glioma group showed significant difference in the 4 parameters (t values:2.730-7.009,all P＜0.01),while the AUCs of the 4 parameters were not significantly different (z values:0.444-1.407,all P＞0.05).Among 37 patients with recurrence confirmed by pathology,there were no significant differences in the semiquantitative parameters between the high-grade and low-grade glioma groups and AUCs were not different either (t values:1.387-1.937,z values:0.106-1.752,all P＞0.05).Conclusions Semiquantitative parameters of 11C-MET PET/CT are equally accurate in the differentiation of recurrence from radiation injury in patients with gliomas,while TBRmean was superior than SUVmean in patients with the high-grade gliomas.Among the patients with recurrence confirmed by pathology,the value of the semiquantitative parameter is limited for the identification of high-and low-grade gliomas.