L-[S-11C-甲基]-蛋氨酸的体内生物分布和PET显像

目的 研究新型脑肿瘤显像剂11C-蛋氨酸的体内生物学分布,探讨11C-蛋氨酸的临床显像方法及其在脑肿瘤显像中的应用.方法 将24只Wistar大鼠按每组4只分为6组,分别由尾静脉注入11C-蛋氨酸,在5、10、20、30、40 min时断头放血处死,采集血液,摘取肝、脑、心、肺、肾、脾等脏器测定放射性计数,测定11C-蛋氨酸在小鼠体内的分布,对健康志愿者和病理证实胶质瘤患者进行PET脑显像.结果与结论 11C-MET在脑肿瘤内有较长的滞留时间,11C-蛋氨酸有较高的肿瘤/脑比值,是理想的脑肿瘤显像剂;11C-蛋氨酸还能实现脑垂体的显像.     

~(11)C-MET PET/CT在脑肿瘤诊断中的初步应用

目的:初步评价11C-MET PET/CT脑显像临床应用价值。方法:研究对象为5例健康志愿者和36例脑部肿瘤患者,健康志愿者行11C-MET PET/CT脑显像,并作为对照组,36例脑部肿瘤患者中19例同时行11C-MET及18F-FDG PET/CT显像,17例仅行11C-MET PET/CT显像;结合健康对照组图像,对本组36例脑部肿瘤患者11C-MET PET/CT脑显像进行分析,并对同时进行18F-FDG PET显像者进行配对比较。结果:所有患者中,11C-MET PET/CT显像阳性者30例,T/B均值为1.72±0.39,18F-FDG PET/CT显像阳性者9例,T/B均值为1.49±0.13。19例患者接受11C-METPET/CT及18F-FDG PET/CT脑显像,T/B均值分别为1.64±0.49及1.16±0.36(t=3.33,P<0.01)。11C-METPET/CT显像诊断脑肿瘤初诊患者灵敏度、特异性及准确性均为100%,其诊断脑肿瘤复发的灵敏度、特异性及准确性分别为94.7%(18/19)、100%(5/5)、95.8%(23/24)。结论:单独行11C-MET PET/CT脑...     

11C-蛋氨酸的快速自动化合成及显像

目的 利用新型CFN-MPS-200多功能合成模块快速合成11C 蛋氨酸(MET)并在脑胶质瘤患者体内对比显像。方法 利用新型CFN-MPS-200多功能合成模块快速合成11C-MET,用HPLC和TLC测定其放化纯,并在脑胶质瘤患者体内对比显像。结果 基于CFN-MPS-200多功能合成模块自动化合成11C-MET的时间约为11 min,合成产率为82±5％(衰减校正后,n=3),放化纯大于99％。产品为无色透明溶液,pH值在70~80之间,产品热源和细菌试验均合格。11C-MET在脑胶质瘤患者脑部显像具有较高的靶本比。结论 利用CFN-MPS-200多功能合成模块制备11C-MET时间短,方法稳定,制备得到的11C-MET放化纯高,在脑胶质瘤患者体内显像具有较高的靶本比,能够较好的区分正常组织与病灶部位。     

11C-胆碱的体内生物分布和PET显像

目的研究新型肿瘤显像剂^11C-胆碱的体内生物学分布，探讨^11C-胆碱的临床显像方法及其在脑肿瘤显像中的应用。方法将24只Wistar大鼠按每组4只分为6组，分别由尾静脉注入^11C-胆碱，在5、10、20、30、40、60分钟时断头放血处死，取肝、脑、血、心、肺、肾、脾等脏器和组织测定放射性计数，测定^11C-胆碱在小鼠体内的分布，对健康志愿者和病理证实胶质瘤志愿者进行正电子发射计算机断层显像的脑显像。结果^11C-胆碱在脑肿瘤内有较长的滞留时间。^11C-胆碱有较高的肿瘤／脑比值，是理想的脑肿瘤显像剂。     

医用回旋加速器生产正电子核素的质量控制

正电子显像剂是实施PET显像的先决条件之一．这些正电子显像剂大多使用11C，13N，15O和18F等正电子核素进行标记，由于它们的半衰期较短，因此这些核素必须由回旋加速器适时生产，并在较短的时间内标记合成为适宜的正电子显像剂供临床PET显像。在这个过程中，回旋加速器生产的放射性核素决定了正电子显像剂的产量。而要提供足额、符合要求的放射性核素，就需要做好回旋加速器的质量控制。     

正电子发射计算机断层显像的临床应用进展

一、脑正电子发射计算机断层(PET)显像 1.脑血流灌注显像:早期以150-H20为显像剂,其初始分布与局部血流量成正比;随着锝标记的显像剂在临床的应用,PET脑灌注显像的应用明显减少。 2.脑代谢显像:18FDG进入脑内后,经脑己糖激酶磷酸化产生6-磷酸FDG滞留于脑细胞内,不参与进一步代谢。局部脑组织FDG利用率是PET-FDG     

11C-MET PET与MRI异机融合对胶质瘤术后残留复发的诊断价值

目的 探讨11C-蛋氨酸-正电子发射断层显像(11C-MET PET)与MRI异机融合在胶质瘤术后残留复发评估中的应用价值.方法 纳入2018年1月至2020年1月该院22例行11C-MET PET及MRI检查的胶质瘤术后患者,将MRI与PET图像融合.最终诊断依据为病理检查或临床随访,计算融合图像、MRI诊断残留复发的诊断效能,并用x2检验和Fisher精确概率法进行对比,将两者诊断效能与最终诊断结果行Kappa一致性分析.结果 MRI、11 C-MET PET与MRI异机融合诊断的灵敏度分别为55.56％(10/18)、100％(18/18),特异度分别为100％(4/4)、50.00％(2/4),准确度分别为63.64％(14/22)、90.91％(20/22),融合图像灵敏度、准确度高于MRI(P =0.003、0.031),特异度差异无统计学意义(P =0.429).MRI诊断结果与最终诊断结果一致性一般(Kappa=0.313);融合图像诊断结果与最终诊断结果一致性较强(Kappa=0.621).结论 11 C-MET PET与MRI异机融合在胶质瘤术后残留复发的评估中灵敏度及准确度高,具有很高的应用价值.     

18F-FDG PET/CT胃癌术前诊断价值探讨

目的探讨PET／CT显像在胃癌术前诊断中的临床应用价值。方法18例术前考虑为胃癌的患者行PET／CT全身显像，并将结果与术后病理对照。结果PET／CT考虑为胃癌18例，术后病理结果均为胃癌。PET／CT诊断胃癌准确度100％．灵敏度100％。淋巴结转移灶的准确率为78．4％，淋巴结外远处转移灶的准确率为100％；灵敏度为93.2％，特异性为28．5％。结论PET／CT对胃癌原发灶及远处转移灶的诊断有较高的临床价值，对手术有较大的指导作用。     

全自动合成3-~(18)F-2-羟基丙烷-2-硝基咪唑及临床前研究

目的研究一种全自动合成肿瘤乏氧显像剂3-18F-2-羟基丙烷-2-硝基咪唑(18F-FMISO)的方法。方法采用改良的FDG(氟代脱氧葡萄糖)模块,在密闭体系下4～6mg前体与F-18离子在110℃反应300s,1mol/LHCl120℃下水解180s,经柱色层纯化得18F-FMISO。检测正常小鼠、荷瘤鼠的生物学分布及PET显像。结果采用FDG模块自动化合成18F-FMISO,合成效率为67%,时间为25min,放化纯度>99%,体外稳定性良好。生物学分布及PET显像表明,肿瘤明显摄取18F-FMISO,120min时瘤/肌比为2.99,但肝、肾、肠的放射性较高。结论改良的FDG模块可高效、快速合成18F-FMISO,其产品质量符合临床要求。18F-FMISO适于胸、颈部肿瘤的乏氧评价。     

PET／CT的原理

PET全称为正电子发射计算机断层显像（positron emission tomography，PET），是反映病变的基因、分子、代谢及功能状态的显像设备。它是利用正电子核素标记葡萄糖等人体代谢物作为显像剂，通过病灶对显像剂的摄取来反映其代谢变化，从而为临床提供疾病的生物代谢信息，是当今生命科学、医学影像技术发展的新里程碑。PET／CT是将PET和CT整合在一台仪器上，     

软组织移植瘤^18F-FDG PET/CT最佳显像时研究

目的研究兔VX2软组织移植瘤的^18F-FDG PET/CT显像及其应用前景。方法36只日本大白兔腿部肌肉种植VX2肿瘤,随机分为4组,分别于2周、4周、6周、8周进行PET/CT显像,获得肿瘤组织和正常组织的标准摄取值（standard uptake value,SUV）。结果VX2移植瘤总成活率为75%;注射18F-FDG后40-100min的SUVmax与20和120min的SUVmax相比有显著差异,P〈0.05。种植VX2肿瘤细胞后2周、4周、6周和8周的肿瘤组织和正常组织的SUV均有显著差异（P=0.005,0.002,0.001,0.007）。结论VX2种植后肿瘤容易成活,PET/CT可以清楚地显示肿瘤的解剖部位、形态、大小和肿瘤细胞的代谢状况,利于及时发现转移,准确的进行肿瘤分期,尽早从分子水平获得对肿瘤恶性程度及预后更准确的把握。     

11C-methionine and 18F-fluorodeoxyglucose positron emission tomography/CT in the evaluation of patients with suspected primary and residual/recurrent gliomas

Background  ¹⁸F-fluorodeoxyglucose (FDG) is the most widely used radiotracer in tumor imaging, but its use for brain gliomas and recurrence is limited by the high ¹⁸F-FDG uptake in normal brain tissue. ¹¹C-methionine (MET) has low uptake in the normal brain tissue, providing potential advantages over ¹⁸F-FDG. The aim of the study was to investigate the diagnostic value of ¹¹C-MET compared to ¹⁸F-FDG positron emission tomography and computed tomography (PET/CT) in patients with suspected primary and residual/recurrent gliomas.

Methods  Eighty paired PET/CT scans using ¹¹C-MET and ¹⁸F-FDG were performed on 44 newly diagnosed patients with suspected gliomas and 36 post-operative patients with suspected residual/recurrent tumors. PET/CT results were evaluated by visual and semiquantitative analysis. The sensitivity, specificity and accuracy for detection of gliomas and residual/recurrent tumors were calculated using visual analysis. Tumor to contralateral normal gray matter (T/G) ratio was calculated for semiquantitative analysis.

Results  Final pathology of the 44 newly diagnosed patients included 26 gliomas (14 high-grade and 12 low-grade tumors) and 18 non-glioma benign lesions. Residual/recurrent gliomas were verified in 28 patients and excluded in 8/36 post-operative patients by subsequent histopathologic examination and/or clinical follow-up for more than six months. The sensitivity, specificity and accuracy of ¹¹C-MET PET/CT were 88.5%, 83.3% and 86.4% for gliomas and 96.4%, 87.5% and 94.4% for residual/recurrent gliomas, respectively. The sensitivity, specificity and accuracy of ¹⁸F-FDG PET/CT were 50.0%, 88.9% and 65.9% for gliomas and 46.4%, 100.0% and 58.3% for residual/recurrent gliomas, respectively. ¹¹C-MET had a higher sensitivity than ¹⁸F-FDG (83.3% vs. 33.3%, P=0.031) in low-grade gliomas, but had no significant difference in sensitivity from ¹⁸F-FDG for high-grade gliomas (92.9% vs. 64.3%, P=0.219). ¹¹C-MET T/G uptake ratios in high-grade gliomas, low-grade gliomas and benign lesions were 1.94±0.53, 1.78±0.61 and 1.06±0.34, respectively. ¹⁸F-FDG T/G uptake ratios in high-grade gliomas, low-grade gliomas and benign lesions were 1.05±0.37, 0.66±0.14 and 0.63±0.17, respectively.

Conclusions  ¹¹C-MET PET/CT is superior to ¹⁸F-FDG PET/CT in detecting and delineating gliomas and residual/recurrent tumors, especially low-grade gliomas and residual/recurrent lesions present in gray matter, but its role in non-invasive grading of the tumors is limited.

     

Further characterization of the epidermal growth factor receptor ligand 11C-PD153035

Background ^11C-4-N-（3-bromoanilino）-6,7-dimethoxyquinazoline （1^11C-PD153035） has been reported as a tracer for imaging human tumors that overexpress epidermal growth factor receptor （EGFR）. However it is still unclear whether ^11C-PD153035 uptake correlates with EGFR expression levels. The objective of this study was to investigate the relationship between ^11C-PD153035 accumulation and EGFR expression levels. Methods Synthesis of ^11C-PD153035 was performed in the Tracerlab FXc system. Accumulation of ^11C-PD153035 by MDA-MB-468, A549 and MDA-MB-231 cells was measured in vitro. There were six tumor-bearing mice in each group. ^11C-PD153035 uptake in tumors was determined by positron emission tomography/computed tomography （PET/CT）. Tumor/normal muscle tissue （TINT） analysis in PET images was applied to quantify the PET data. Sixty minutes after PET/CT scanning, the nude mice were sacrificed and the tumors were excised. The ^11C-PD153035 accumulation in different tumors was determined by a gamma counter. Results Close correlation existed between the uptake and the level of EGFR expression both in vitro and ex vivo （r^2=0.72, P〈0.001; r^2=0.63, P=0.003）. When the static TINT analysis method was applied to analyze the PET data, the observed correlation was again excellent （^2=0.70, P=-0.001）. Conclusions The uptake of PET tracer ^11C-PD153035 closely correlates with the EGFR expression levels in tumor cells. ^11C-PD153035 has the potential to yield useful information for both cancer diagnosis and therapy.     

18F-FDG PET/CT在肝癌患者接受肝脏器官移植术前、后的临床应用价值

目的 评价^18F-FDG PET—CT在肝癌患者肝移植术前评估和在术后早期发现小复发病灶中的价值。方法 回顾性分析19例肝癌患者拟行或已行肝移植手术患者的临床和^18F—FDG PET—CT影像学资料。肝移植术前进行^18FDG PET-CT扫描8例10次,肝移植术后进行^18F-FDG PET—CT扫描者22次（11例患者）。结果 8例肝移植术前评估的患者中有2例PET显像全身各部位均未发现转移性病灶．均按期接受了肝移植手术;有2例PET显示转移灶位于拟手术野区域内,故也按期进行了移植手术（术中对局部的转移灶做了外科清扫）;有4例患者因已有不同程度的远处转移,与家属讲明原因后放弃肝移植手术,而改用介入或其他内科治疗。肝移植术后进行扫描者22次（11例患者）,其中2例患者术后行PET检查未发现肿瘤复发及全身其他部位的转移灶：1例患者术后发现霉菌性脑脓肿：在其余19次（8例患者）PET检查中发现移植的肝内出现复发病灶者4例．另外还发现肝左右静脉和下腔静脉内癌栓、肺内、多部位多发淋巴结、骨、脾脏内、胸壁胸膜、胸椎椎间孔等处转移征象。结论 ^18F—FDG PET—CT全身性扫描兼有对肿瘤显示高度敏感性的两个优势,在肝移植术前评估和术后早期发现复发病灶的临床应用中均起着重要和不可替代的作用。     

18FDG PET/CT在肺癌致异位ACTH综合征诊断中的应用

目的:探讨¹⁸F-脱氧葡萄糖(¹⁸FDG)正电子发射计算机断层显像(PET)/计算机断层显像(CT)在肺癌致异位促肾上腺皮质激素(ACTH)综合征(EAS)中的图像特点,提高EAS诊断的准确率。 方法:8例经手术病理证实为肺癌的EAS患者,术前行¹⁸FDG PET/CT躯干和脑显像,同期行鞍区脑核磁共振成像(MRI)、胸部高分辨CT显像、奥曲肽(OCT)全身显像和岩下窦静脉取血(IPSS)。对¹⁸FDG PET/CT图像所示肺部病变行半定量分析,计算病变最大标准摄取值(SUV_max)及病变/正常肺组织SUV_max比值。 结果:18例EAS包括2例类癌,4例不典型类癌,2例小细胞肺癌。8例IPSS患者ACTH水平中央与外周比较无明显差别。26例(75%)患者初诊时胸部CT示肺内结节,2例为不典型病变。5例同期MRI示垂体微腺瘤,2例(25%)OCT显像为阳性。38例(100%)肺部病变¹⁸FDG PET/CT表现为结节样、团块样或斑片样代谢增高,肿瘤的SUV_max为0.72~14.05(3.67±4.68),病变/正常肺组织SUV_max比值为1.69~27.54(8.14±9.63);8例双侧肾上腺均为团状代谢异常增高,同时4例提示垂体瘤。 结论:肺癌是EAS的常见原因,其中以类癌多见,在¹⁸FDG PET中代谢多轻度增高,PET可以作为有效的定位辅助诊断方法。     

PET显像剂18F-AlF-NOTA-PRGD2的肿瘤靶向性

目的研究新型PET受体靶向显像剂18F-AlF-NOTA-PRGD2用于肿瘤显像的可行性。方法18F-AlF-NOTA-PRGD2采用
18 氟-氟化铝（18F-AlF）与NOTA-PRGD2在100 ℃下通过鳌合反应标记制备而得。荷脑胶质瘤U87MG裸鼠经尾静脉注射
18F-AlF-NOTA-PRGD2后行体内放射性生物学分布和PET/CT、microPET/CT显像研究。结果18F-AlF-NOTA-PRGD2采用一步
法成功标记,反应时间15~20 min,标记产率为17%~25%。体内放射性生物学研究显示该显像剂能靶向肿瘤病灶,静脉注射后
1 h和2 h肿瘤摄取量分别达4.14±1.44、2.80±1.18% ID/g（t=1.910,P=0.070）,肿瘤/脑比值分别达2.95±0.61、5.21±2.62（t=-1.686,
P=0.167）。PET/CT和microPET/CT显像均可清楚显示该显像剂在荷瘤鼠体内的放射性分布情况,肿瘤显像清楚,体内分布良
好,但microPET/CT图像质量明显优于PET/CT。结论18F-AlF-NOTA-PRGD2标记简单、易行,在荷瘤鼠体内具有优良的肿瘤靶
向性,可发展成为PET肿瘤显像剂。     

Whole-body MRI including diffusion-weighted MRI compared with 5-HTP PET/CT in the detection of neuroendocrine tumors

Aim: We wanted to explore if whole-body magnetic resonance imaging (MRI) including diffusion-weighted (DW) and liver-specific contrast agent-enhanced imaging could be valuable in lesion detection of neuroendocrine tumors (NET). [11C]-5-Hydroxytryptophan positron emission tomography/computed tomography (5-HTP PET/CT) was used for comparison.

Materials and methods: Twenty-one patients with NET were investigated with whole-body MRI, including DW imaging (DWI) and contrast-enhanced imaging of the liver, and whole-body 5-HTP PET/CT. Seven additional patients underwent upper abdomen MRI including DWI, liver-specific contrast agent-enhanced imaging, and 5-HTP PET/CT.

Results: There was a patient-based concordance of 61% and a lesion-based concordance of 53% between the modalities. MRI showed good concordance with PET in detecting bone metastases but was less sensitive in detecting metastases in mediastinal lymph nodes. MRI detected more liver metastases than 5-HTP PET/CT.

Conclusion: Whole-body MRI with DWI did not detect all NET lesions found with whole-body 5-HTP PET/CT. Our findings indicate that MRI of the liver including liver-specific contrast agent-enhanced imaging and DWI could be a useful complement to whole-body 5-HTP PET/CT.     

18F-FDG PET/CT显像在诊断乳腺癌中的价值

目的探讨18F-脱氧葡萄糖（Fluorine-18 fluorodeoxyglucose,FDG）正电子发射计算机断层显像（positrone mission computer tomography,PET/CT）在乳腺癌术前诊断中的价值。方法 27例乳腺包块的女性患者,PET/CT全身显像行鉴别诊断和分期。PET/CT结果由手术病理证实。结果病理证实15例为乳腺癌,12例为良性包块。15例中PET/CT诊断阳性14例,漏诊1例,其它影像学方法（CT、乳腺钼靶、超声）诊断11例;12例中PET/CT诊断阴性10例,误诊2例,其它影像学方法诊断阴性7例。PET/CT在诊断乳腺癌的灵敏度、特异性、准确性、阳性预测值和阴性预测值分别为14/15（93.3%）、10/12（83.3%）、24/27（88.8%）、14/16（87.5%）、10/11（90.1%）。病理证实15例乳腺癌中的12例有同侧腋窝淋巴结转移,18F-FDGPET/CT诊断阳性10例,假阴性2例。结论 18F-FDGPET/CT显像是鉴别诊断乳腺癌的较准确方法。