PET_CT在脑胶质瘤放疗后复发与坏死鉴别诊断中的应用研究.pdf

安徽医科大学硕士学位论文PET/CT在脑胶质瘤放疗后复发与坏死鉴别诊断中的应用研究姓名：刘云琴申请学位级别：硕士专业：肿瘤学指导教师：钱立庭20100501安徽医科大学硕士学位论文 2 PET-CT 在脑胶质瘤放疗后复发与坏死鉴别诊断中的应用研究 摘 要 目的目的 鉴别脑胶质瘤放疗后复发与坏死有重要临床意义，本研究应用正电子发射断层显像/X 线计算机断层成像（Positron emission tomography/X-ray computed tomography ，PET/CT）评价11C-蛋氨酸(11C-methionine ，MET)在脑胶质瘤放疗后复发与坏死的鉴别诊断中的作用,同时观察放疗后复发脑胶质瘤的治疗疗效 方法方法 自 2008 年 6 月至 2009 年 9 月， 30 例放疗后怀疑复发或坏死胶质瘤患者接受 MET PET/CT 检查首次治疗时病理分级根据世界卫生组织（WHO）中枢神经系统分类方法，II 级 19 例，III 级 9 例，IV 级 2 例30 例患者首次治疗均接受手术切除及辅助放疗，放疗剂量范围 54-60Gy，中位剂量 58Gy; 30 例中 17 例接受了术后化疗。

所有患者均接受 MET PET/CT 检查，放疗结束与 PET/CT 检查间隔时间范围 5-90 月,中位间隔时间 13.5 月PET 检查时患者年龄范围 11-69 岁，中位年龄 41 岁； 男性 21 例， 女性 9 例 PET/CT 仪为 Biograph HR16 机型 （Siemens，Germany） ，患者静脉注射 740MBq 的11C-MET 后 10 分钟进行扫描，通过衰减校正后重建 PET 影像 （3mm 层厚） 蛋氨酸 （MET） 高代谢区被选做感兴趣区(Regions of interest,ROI） ，同时以同样大小的圆圈选定对侧灰质区多个 ROIS，计算平均值，如果 PET 未发现异常， MRI 异常区域相应的 PET 影像区域选定圆形 ROI SUV(标准摄取值)=（像素值/像素体积）/（注射的放射性核素活度/体积）×校正因子L/N(the lesion-to-normal tissue ratio,病灶正常组织比)=病灶部位 SUV平均值/对侧灰质 SUV平均值生存时间从 PET/CT 检查后开始计算确立放疗后复发的诊断需安徽医科大学硕士学位论文 3 根据手术切除或活检病理结果，放疗后坏死的诊断需根据手术病理结果或临床随访，在长时间（大于 6 个月）CT 或 MRI 随访中显示病灶自发性缩小或稳定的患者诊断为放射性坏死。

结果结果 30例患者均接受一次PET/CT检查并随访至2010年3月 （中位随访11月） PET/CT 诊断 19 例复发，11 例坏死19 例 PET 检查后考虑复发患者接受手术切除或立体定向活检,18 例病理明确诊断为胶质瘤复发, 1 例手术切除诊断为放疗后坏死18 例病理证实复发患者中 1 例复发前病理诊断为星形胶质细胞瘤Ⅱ级，复发后病理诊断为少枝胶质瘤伴室管膜分化（WHOⅡ级） ；10 例复发后病理诊断无改变；7 例复发前病理诊断为星形胶质细胞瘤Ⅱ级，复发后病理诊断为星形胶质细胞瘤Ⅲ级11 例 PET/CT 诊断为放疗后坏死，经长期随访（＞6 个月）后临床症状稳定及 MRI 或 CT 影像诊断病灶无增大根据以上结果用四格表计算 MET PET 鉴别脑胶质瘤放疗后复发与坏死的敏感性,特异性和准确性分别为100%,91.7%和 96.7%全组仅复发组 3 例活检后死亡（1 例未治疗病情进展后死亡， 1 例立体定向放疗和 1 例化疗后病情进展死亡） 复发组 18 例 1 年生存率 82%,生存时间 5-15 月，中位生存时间 8.5 月复发后手术切除患者与立体定向活检患者的生存率有明显差异（P=0.002） 。

结论结论 MET PET 可有效鉴别脑胶质瘤放疗后复发与坏死； 复发脑胶质瘤患者手术切除较活检生存获益的可能性更大 关键词关键词 脑胶质瘤 放射疗法 正电子发射断层显像 鉴别诊断 放疗坏死安徽医科大学硕士学位论文 4 Study on the differential diagnosis of recurrent tumor from radiation necrosis after radiotherapy of glioma with positron emission tomography Abstract Objective Differential diagnosis between tumor recurrence and radiation necrosis is important in the clinical management of glioma after radiotherapy.In this study,we evaluate the value of 11C-methionine positron emission tomography/ X-ray computed tomography (MET PET/CT) in differentiation of tumor recurrence from radiation necrosis and the therapeutic results of recurrent glioma. Methods From June 2008 to September 2009, 30 patients who had previously been treated with radiotherapy were suspected to have recurrent glioma or radiation injury.MET PET was performed on these patients. According to the World Health Organization (WHO) classification, initial tumor histologies included 19 grade Ⅱ, 9 grade Ⅲ and 2 grade Ⅳ.30 patients had previously received operation and adjuvant radiotherapy,the dose of initial radiotherapy range from54 to60Gy(median dose 58Gy)；only 17 received adjuvant chemotherapy after operation. The median time between initial radiotherapy and PET was 13.5 months,ranging from 5 to 90 months．There were 21 males and 9 females,the median patient age was 41 years ,ranging from 11 to 69 years. PET was carried out with Biograph HR16 scanner（Siemens，Germany） ，PET images were obtained as a static scan 10 minutes after injection of 740MBq MET.The PET images were reconstructed using measured 安徽医科大学硕士学位论文 5 attenuation reconstruction(3mm ).On PET scans,the portion of the tumor with the highest accumulation was selected as the region of interest(ROI),and several ROIs with the same diameter were located over the gray matter of the contralateral lobe.If no abnormality could be detected ,a circular ROI of the same size was located over the area corresponding to the MRI abnormality.The standardized uptake value(SUV) was caculated over the same tumor ROI as follows:SUV=[(pixel count/pixel volume)/(injected radioisotope activity/body weight)]×calibration factor. L/N(the lesion-to-normal tissue ratio )= SUVmean of the lesion/ SUVmean of the contrallateral gray matter. The survival time was calculated from the day of performing PET.The tumor recurrence was confirmed by correlating findings with subsequent histological analysis,the diagnosis of necrosis was based on histological analysis and the subsequent clinical follow-up(＞6 months) and MRI/ CT in case without surgery or biopsy. Results The follow-up investigation continued to March 2010(the median time 11 months).19 recurrence and 11 radiation necroses were shown in PET images． There are 19 cases considered to have recurrent tumor were eveluated by histopathological findings,18 showed viable glioma and 1 showed necrosis .Within 18 recurrent cases,1 case whose initial tumor hisyology was WHO grade II was pathologically confirmed as having oligodendroglioma mixed with ependymoma;10 cases had the same hisyology after recurrence;7 cases whose initial tumor histology was WHO grade II was pathologically confirmed as having anaplastic astrocytoma. While 11 cases were considered to have radiation necrosis because they exhibited stable neurological sympotoms with no sign of massive enlargement of the 。