1、PET显像在脑肿瘤诊断中的应用,中山大学附属第一医院核医学科 张祥松,脑解剖特点,脑位于坚固的颅骨内，难以活检。影像学检查是颅内病变定性诊断的主要手段。,女，23岁；右额痛2月，Gd-DTPA MRI诊断为脑胶质瘤，术中病理：炎症。,常规影像学检查,解剖显像 CT：平扫增强 MRI ：T1WI、T2WI，Gd-DTPA增强功能显像 Perfusion CT imaging：CBF、rCBV、MTT MRI：DWI、DTI、MRS Perfusion MR Imaging (DSC、DCE),A: FLAIR; B:Ga-DTPA; C:DWI; D:ADC; E: rCBV; F&G: MRS
2、,常规功能MRI,Sensitivity 97%, Specificity 67%,PET显像原理,基本原理：放射性示踪技术,PET/CT显像特点,功能与解剖成像的完美结合主要正电子放射性核素均为人体基本组成元素或性质相近，其标记化合物性质基本不变正电子核素分子探针多样性,PET在脑肿瘤的临床应用,诊断和鉴别诊断肿瘤累及范围分级疗效预测和评估预后评估,脑肿瘤生物学特性,InvasionIncreased proliferation rateCapability of forming new blood vesselsDecrease rates of cell deathOver- and u
3、nderexpression of receptors/tumor antigensHypoxiaNecrosisIncreased metabolism of glucose, amino acids, and membrane precursorsAccelerated rates of apoptosis,PET分子成像靶点：细胞膜+细胞内+细胞间质,葡萄糖代谢18F-FDG,优点 应用广泛，广谱肿瘤显像剂，全身显像 恶性程度分级 肿瘤复发/残余与放射损伤的鉴别诊断 脑淋巴瘤诊断有价值 不足 低度恶性脑肿瘤灵敏度低 T/N比值低 假阳性,葡萄糖代谢FDG,右颞叶混合型神经胶质瘤（级）。F
4、DG-PET延迟显像病灶浓聚增加,葡萄糖代谢FDG,左侧额叶星形细胞瘤（WHO级）,肺癌脑转移,FDG,13N- NH3,葡萄糖代谢FDG,葡萄糖代谢FDG,室管膜瘤术后残留或复发？随访7年未见肿瘤复发。,葡萄糖代谢FDG,间变型少突胶质细胞瘤（级）术后复发,葡萄糖代谢FDG,Resonfeld et al. J Nucl Med. 1992; 33:532-536,淋巴瘤,化疗前 化疗后,葡萄糖代谢FDG,Resonfeld et al. J Nucl Med. 1992; 33:532-536,脑脓肿,真菌性肉芽肿,FDG假阳性,单纯疱疹病毒性脑炎,氨基酸类,优点灵敏度高T/N比值高显示肿
5、瘤浸润范围较准确不足恶性程度分级假阳性,氨基酸类MET,18F-FDG PET,11C-MET PET,左胼胝体胶质瘤（II级）,氨基酸类MET,Goldman et al. J Nucl Med 1997; 38:1459-1462,氨基酸类MET,Tumor Infiltration,Solid Tumor,Kracht et al. Clinical Cancer Research 2004; 10:7163-7170,氨基酸类FDOPA,Chen et al. J Nucl Med. 2006; 47:908-911,氨基酸类FET,Edema and Astrogliosis,Ast
6、rocytomaGrade ,Pauleut et al. Brain 2005;125:678-687,核酸代谢FLT,Chen. J Nucl Med. 2005; 46:948-952,CONCLUSION: FLT was more sensitive than FDG to image recurrent high-grade tumors, correlated better with Ki-67 values, and was a more powerful predictor of tumor progression and survival. Thus, FLT appear
7、s to be a promising tracer as a surrogate marker of proliferation in high-grade gliomas.,核酸代谢FLT,R=0.84,R=0.51,Chen. J Nucl Med. 2005; 46:948-952,磷脂代谢CHO,脑转移瘤检出率较高,11C-Choline PET 18F-FDG PET,左侧额叶脑转移瘤,18F-FDG,11C-CHOLINE,磷脂代谢CHO,乏氧显像FMISO,Bruehlmeier et al. J Nucl Med. 2004; 45:1851-1859,CONCLUSION:
8、 FMISO provide a spatial description of hypoxia in brain tumors that is independent of BBB disruption and perfusion.,乏氧显像FMISO,HV: 129cm3, T/B: 3.0T0: 20cm3, T1Gd: 80cm3, T2: 169cm3,HV: 5.3cm3, T/B: 1.6T0: 1cm3, T1Gd: 7cm3, T2: 37cm3,Alexander et al. Clin Cancer Res. 2008; 14: 2623-2630,乏氧显像FMISO,Al
9、exander et al. Clin Cancer Res. 2008; 14: 2623-2630,乏氧容积,乏氧比值,肿瘤血管生成RGD,“In contrast to the relatively disappointing results with other targeted molecular therapies, there has been real progress with agents that inhibit angiogenesis.”,“New developments in targeted molecular therapies for glioblastom
10、a” Wen et al. Expert Rev. Anticancer Ther. 2009; 9:7-10,脑肿瘤血管生成,Miller et al. J Natl Cancer Inst. 2005; 95：172-187,肿瘤血管生成RGD,胶质瘤整合素v3表达增高,Chen et al. J Nucl Med. 2008; 45:1176-1183,氨代谢NH3,13N-NH3的特性13NH3和13NH4+两种水化形式存在 13NH4+是K的类似物 13NH3脂溶性有限，比乙醇低4-100倍 脑肿瘤组织选择性表达GS酶 脑肿瘤组织过渡表达K+(ATP)）和（K+(Ca)）,氨代谢NH
11、3,小分子高灵敏度与脑肿瘤特异性结合高特异性,13N-NH3,分子量： 547 17,氨代谢NH3,J Neuro-oncol. 2006; 78:141-151,氨代谢NH3,J Neuro-oncol. 2007; 82:305-311,氨代谢NH3,PET诊断： 小脑星形细胞瘤（级）,18F-FDG,13N-NH3,18F-FDG 13N-NH3 11C-MET 11C-CHO,-脑肿瘤代谢显像剂,MRI增强,FDG,NH3,MET,-低级别星形细胞瘤典型代谢表型,星形细胞瘤II级,星形细胞瘤II级,CT/MRI,18F-FDG,13N-NH3,11C-MET,脑脓肿,星形细胞瘤III级
12、,-颅内感染、炎症性病变代谢表型,MRI诊断海绵状血管瘤合并出血，不除外星形细胞瘤,PET诊断低级别星形细胞瘤,手术病理：星形细胞瘤II级,FDG,13N-NH3,11C-MET,MRI,CT,FDG,13N-NH3,MRI疑诊恶性脑肿瘤,PET/CT诊断出血性脑梗死,氨代谢NH3,诊断：右侧颞叶及海马病变，结合MRI及DWI表现及既往影像资料，不支持肿瘤，考虑炎性病变可能性大,麦润金 女 55岁，81512,氨代谢NH3,诊断：星形细胞瘤（级）,星形胶质瘤II级手术并放化疗后7个月,18F-FDG显示轻度摄取,13N-NH3无摄取,放射性坏死,MRI诊断胶质瘤复发,胶质母细胞瘤,手术加放化疗
13、后三个月,11C-MET假阳性表现(二次手术证实为坏死),-氨基酸类PET显像剂也有假阳性!,胶质母细胞瘤术后2周,MRI增强,18F-FDG,13N-NH3,胶质母细胞瘤,淋巴瘤,-脑肿瘤代谢表型差异性,淋巴瘤,18F-FDG,13N-NH3,MRI,？,MRI,FDG,13N-NH3,胶质母细胞瘤,？,MRI,FDG,13N-NH3,淋巴瘤,-鞍区脑肿瘤代谢表型差异性,垂体瘤,脑膜瘤,MRI增强,18F-FDG,13N-NH3,中山一院院本部MR诊断：脑膜瘤可能性大黄埔院区MR诊断：鼻咽癌可能性大,MR增强,18F-FDG,13N-NH3,手术病理：脑膜瘤I级,MR诊断：脑膜瘤临床疑问：泌乳素升高，溴隐亭治疗有效，垂体瘤？海绵状血管瘤？,MR增强,18F-FDG,13N-NH3,良性脑膜瘤I级？,Clin Nucl Med 2014;39: 605-608,18F-FDG,11C-MET,13N-NH3,垂体瘤术后，MR检查阴性，PET/CT检查发现复发肿瘤，并显示残余垂体组织,刘丹燕，女，19岁,18F-FDG （准确性40）11C-Methionine （灵敏度最高） 13N-Ammonia （特异性最好）,三种示踪剂组合使用准确性90%,THANK YOU!,
