18F-氟脱氧葡萄糖和11C-胆碱在孤立性肺结节诊断中的应用

^18F-．氟脱氧葡萄糖（^18F-FDG）和^11C-胆碱（^11C-choline）在孤立性肺结节（SPN）的定性诊断方面各有优势，两者联用可以互相弥补不足，效果较好。^18F-FDG对恶性SPN以及淋巴结转移判断的敏感性和特异性较高，^11C-胆碱可以降低炎性病变的假阳性率，有利于恶性SPN脑转移的诊断。但^11C-胆碱PET和^18F-FDGPET一样无法显示细支气管肺泡癌、小细胞肺癌等代谢较低的SPN。有报道，^18F-氟脱氧胸苷（^18F-FLT）可用于对肿瘤进行良恶性鉴别、疗效评估和预后判断，被认为是一种具有良好应用前景的PET显像剂。     

11C-胆碱与18F-FDG双时相PET显像在孤立性肺结节鉴别诊断中的应用

目的 比较^11C-胆碱、18F-脱氧葡萄糖（FDG）和^18F-FDG双时相PET显像对鉴别肺部孤立性结节良恶性的价值。方法16例临床疑为肺肿瘤的患者进行^18F-FDGPET显像（注药后1h显像，2h后行延迟显像）、^11C-胆碱PET显像（3d内，于注药后10min进行）。图像判断以标准摄取值（SUV）作为半定量指标，异常放射性浓聚灶以SUV〉2．5为葡萄糖代谢增高，^18F-FDG延迟显像SUV上升≥10％为恶性病变（阳性），如下降或升高〈10％为良性病变（阴性）；^11C-胆碱异常摄取灶以SUV〉2．0为阳性。所有病例进行随访，以显像诊断是否符合病理检查结果作为判断标准。结果病理检查结果证实12例肺癌，3例结核，1例结节病。^11C-胆碱PET显像确诊了12例肿瘤中的ll例，而^18F-FDG PET显像确诊10例（10／12例），双时相^18F-FDG PET显像确诊11例。4例良性病变者，^11C-胆碱PET显像能较好鉴别；而^18F-FDG PET显像2例假阳性，结合延迟显像仅1例假阳性。结论 ^11C-胆碱和^18F-FDG PET显像均能较好地鉴别肺部良恶性肿瘤。但^11C-胆碱和双时相^18F-FDGPET显像优于常规^18F-FDGPET显像，三者联合能提高对肺部病变的诊断效率。     

正电子药物在肿瘤诊断中的进展

正电子发射型体层显像(PET)在肿瘤的早期诊断、分期、良恶性鉴别以及复发监测中有着广泛的应用。18F-氟代脱氧葡萄糖(18F-FDG)是目前最成熟的正电子肿瘤显像剂,但是18F-FDG在部分肿瘤中的显像结果并不理想。11C-甲硫氨酸(11C-MET)、11C-乙酸(11C-acetate)、11C-胆碱(11C-choline)、18F-脱氧胸苷(18F-FLT)等各类非葡萄糖代谢的正电子显像剂逐渐投入临床使用,它们将和18F-FDG互补,提高各种肿瘤诊断的敏感性、特异性和准确率。     

多巴胺转运体显像剂^11C—CFT和^18F-CFT及其临床应用进展

使用^11C和^18F标记的托烷类衍生物的正电子显像剂是目前临床常规使用的正电子显像剂,^11C标记的显像剂^11C-2β-碳甲氧基-3β-（4-氟苯基）托烷（^11C—CFT）具有合成方法简单、比活度高、成本低等优点,但是^11C半衰期太短而限制了其临床使用;^18F—CFT具有半衰期长、临床使用方便而受到重视。^11C—CFT和^18F—CFT PET均被用于临床早期诊断帕金森病和对药物治疗疗效的监测。     

^11G—MET PET在脑肿瘤中的应用

^11G-NET（^11G-蛋氨酸）是目前用于肿瘤PET最多的氨基酸类显像剂之一，它能反映体内氨基酸的转运、肿瘤氨基酸的代谢及蛋白质的合成。^11G-MET PET能用于脑肿瘤的诊断、区分肿瘤复发及放射性坏死，早期评价治疗效果，尤其对肿瘤周边组织及低度恶性肿瘤的诊断要优于^18F-FDG PET、CT和MRI。     

除FDG以外的用于肿瘤PET显像的^18F标记物

综述了除FDG以外的用于肿瘤PET显像的^18F标记物的研究和应用。这些^18F标记物主要包括：与相应受体结合的^18F标记的蛋白质和多肽，^18F标记的乏氧显像剂，用于评价基因治疗的^18F标记物等。此外，还介绍了用于诊断不同恶性肿瘤的^18F标记的组织特异性PET显像剂。     

11C-胆碱PET在前列腺癌中的临床应用探讨

前列腺癌是老年男性的常见恶性肿瘤,但是常规显像困难.11C-胆碱是新近研究较多的一种正电子肿瘤阳性显像剂,因它不通过泌尿系统排泄而被用于前列腺癌的临床诊断中.通过11C-胆碱、18F-氟脱氧葡萄糖、11C-乙酸和11C-甲硫氨酸在前列腺癌PET结果的比较,总结了11C-胆碱PET在前列腺癌的临床应用近况.     

11C-乙酸盐在肿瘤PET或PET-CT中的应用

18F-FDG是临床上应用最多、范围最广的正电子显像剂,但其对于某些肿瘤的诊断缺乏敏感性和特异性.11C-乙酸盐与18F-FDG相比,有不同的体内分布方式及细胞摄取机制,是近年来众多研究证实很有希望在某些方面弥补 18F-FDG显像不足的正电子显像剂.该文综述了目前11C-乙酸盐PET或PET-CT的机制、研究领域及最...     

11C-乙酸盐PET显像在肾脏肿瘤诊断中的作用

目的探讨^11C-乙酸盐PET显像在肾脏肿瘤诊断中的作用及其与^18F-脱氧葡萄糖（FDG）肾肿瘤显像的关系。方法29例疑肾肿瘤患者行^11C-乙酸盐PET早期及延迟显像，其中22例1周内行^18F—FDG PET显像。所有患者均有手术病理检查或CT、随访结果。患者静脉注射^11C-乙酸盐后即刻采集肾脏部位早期图像，以反映肾皮质血流灌注；10min后采集延迟图像，以反映^11C-乙酸盐在肾皮质内的代谢。观察^11C-乙酸盐在人体内的分布，并比较^11C-乙酸盐与^18F—FDG肾肿瘤显像的阳性率及其与病理类型、分级的关系。结果^11C-乙酸盐在人体内以胰腺摄取最高，并可能经胰液分泌人肠道。肾皮质对^11C-乙酸盐摄取随时间而变化，延迟相大部分原发肾皮质肿瘤（13例中分级Ⅰ～Ⅱ为12例）对^11C-乙酸盐摄取高于正常肾皮质，阳性率为76．9％（10／13例）；而^18F—FDG显像仅为30．8％（4／13例）。6例肾盂输尿管移行细胞癌^11C-乙酸盐显像阳性仅2例；其中5例行^18F—FDG显像，均阳性。1例肾血管平滑肌脂肪瘤^11C-乙酸盐早期及延迟显像均清晰显示，2例输尿管炎症对^11C-乙酸盐无摄取。结论^11C-乙酸盐PET显像对恶性程度较低的肾皮质肿瘤显像阳性率较高，可弥补^18F—FDG显像的不足。     

PET在前列腺癌中的应用

前列腺癌是老年男性最常见的恶性肿瘤之一,PET在其早期诊断和准确分期方面具有重要价值。18F-氟代脱氧葡萄糖(18F-FDG)PET对前列腺癌的检出并不敏感,也不能可靠进行淋巴结分期,但18F-FDG摄取与疾病进展程度相关。11C-胆碱PET诊断前列腺癌的准确率高,在淋巴结及骨转移的检出方面也明显优于18F-FDGPET,但其半衰期短而限制了临床应用。18F-胆碱的肿瘤摄取与11C-胆碱相似,但在泌尿系统排泄较高。其他示踪剂如11C-乙酸、11C-甲硫氨酸、18F标记的雄激素等在前列腺癌的诊断、分期及疗效评价方面也具有一定价值。     

11C-acetate PET imaging of prostate cancer.

11C-Acetate can act as a probe of tissue metabolism through entry into catabolic or anabolic metabolic pathways as mediated by acetyl-coenzyme A. The uptake of (11)C-acetate in prostate cancer was investigated to determine whether this tracer has potential in tumor identification. METHODS: Twenty-two patients with prostate cancer underwent PET after intravenous administration of 740 MBq (11)C-acetate. Eighteen of the 22 patients were also investigated with (18)F-FDG PET. Standardized uptake values (SUVs) for each tumor were investigated for tracer activity at 10-20 min after (11)C-acetate and 40-60 min after (18)F-FDG administration. RESULTS: Adenocarcinoma of the prostate showed variable uptake of (11)C-acetate, with SUVs ranging from 3.27 to 9.87. In contrast, SUVs for (18)F-FDG ranged from 1.97 to 6.34. By visual inspection, (11)C-acetate accumulation in primary prostate tumors was positive in all patients, whereas (18)F-FDG accumulation was positive in only 15 of 18 patients. (11)C-Acetate PET in a patient with lymph node metastasis showed high intrapelvic accumulation corresponding to metastatic sites. Similarly, 2 patients with bone metastases were (11)C-acetate avid. CONCLUSION: (11)C-Acetate shows marked uptake in prostate cancer and is more sensitive in detection of prostate cancer than is (18)F-FDG PET. (11)C-Acetate represents a new tracer for detection of prostate cancer with PET, measuring radiopharmaceutical uptake pathways that are different from those measured by (18)F-FDG.     

Positron emission tomography with 11C-acetate and 18F-FDG in prostate cancer patients

Visualisation of primary prostate cancer, its relapse and its metastases is a clinically relevant problem despite the availability of state-of-the-art methods such as CT, MRI, transrectal ultrasound and fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET). The aim of this study was to evaluate the efficacy of carbon-11 acetate and (18)F-FDG PET in the detection of prostate cancer and its metastases. Twenty-five patients were investigated during the follow-up of primary prostate cancer, suspected relapse or metastatic disease using (11)C-acetate PET; 15 of these patients were additionally investigated using (18)F-FDG PET. Fourteen patients were receiving anti-androgen treatment at the time of the investigation. Lesions were detected in 20/24 (83%) patients using (11)C-acetate PET and in 10/15 (75%) patients using (18)F-FDG PET. Based on the results of both PET scans, one patient was diagnosed with recurrent lung cancer. Median (18)F-FDG uptake exceeded that of (11)C-acetate in distant metastases (SUV =3.2 vs 2.3). However, in local recurrence and in regional lymph node metastases, (11)C-acetate uptake (median SUVs =2.9 and 3.8, respectively) was higher than that of (18)F-FDG (median SUVs =1.0 and 1.1, respectively). A positive correlation was observed between serum PSA level and both (11)C-acetate uptake and (18)F-FDG uptake. (11)C-acetate seems more useful than (18)F-FDG in the detection of local recurrences and regional lymph node metastases. (18)F-FDG, however, appears to be more accurate in visualising distant metastases. There may be a role for combined (11)C-acetate/(18)F-FDG PET in the follow-up of patients with prostate cancer and persisting or increasing PSA.     

11C-乙酸盐PET/CT显像在中、高分化肝细胞肝癌复发与转移监测中的应用研究

目的探讨11C-乙酸盐PET/CT显像在中、高分化肝细胞肝癌（HCC）复发与转移监测中的应用价值。方法回顾性分析2015年1月至2016年12月行11C-乙酸盐和18F-FDG PET/CT躯干显像的10例中、高分化HCC男性患者,其中,中分化HCC 6例,高分化HCC 4例。患者经手术或介入治疗后,甲胎蛋白进行性升高,比较11C-乙酸盐和18F-FDG PET/CT的诊断价值。PET图像上代谢高于正常肝脏组织的病灶判定为阳性,低于或类似于正常肝脏组织的病灶判定为阴性。通过勾画感兴趣区计算病灶及本底最大标准化摄取值（SUV_max）及靶/本底比值（T/B）。所有患者最终通过病理或影像学检查确诊转移或复发。结果11C-乙酸盐显像发现18个阳性病灶,灵敏度为100%（18/18）;18F-FDG显像发现5个阳性病灶,灵敏度为27.8%（5/18）;两种示踪剂同时发现5个阳性病灶（在4例中分化HCC患者中）,11C-乙酸盐显像探测病灶的灵敏度与两种示踪剂联合显像相同。11C-乙酸盐显像病灶SUV_max为1.3~14.2,T/B为1.1~14.3;18F-FDG显像病灶SUV_max为0.5~3.4,T/B为0.6~1.1。8例患者（13个病灶）病理证实为肿瘤复发或转移,2例患者（5个病灶）3个月后复查PET/CT或CT证实为转移。结论11C-乙酸盐显像可显著提高中、高分化HCC复发与转移诊断的灵敏度;推荐使用11C-乙酸盐显像用于监测中、高分化HCC的复发与转移。     

11C-acetate PET imaging in hepatocellular carcinoma and other liver masses.

It is well known that (18)F-FDG PET has a high average false-negative rate of 40%-50% in the detection of hepatocellular carcinoma (HCC). This is not an acceptable accuracy, particularly in countries where this tumor is prevalent. In this study, we evaluated prospectively the characteristics of (11)C-acetate and (18)F-FDG metabolism in HCC and other liver masses. METHODS: Fifty-seven patients were recruited into this study, with masses consisting of 39 HCC; 3 cholangiocarcinomas; 10 hepatic metastases from lung, breast, colon, and carcinoid primary malignancies; and 5 benign pathologies, including focal nodular hyperplasia (FNH), adenoma, and hemangioma. All patients, except 2 with typical findings of hemangioma and 3 clinically obvious metastases, were confirmed histopathologically by liver biopsy or resection. All patients fasted for at least 6 h and blood glucose concentration was measured before they underwent dual PET radiopharmaceutical evaluation of the upper abdomen with (11)C-acetate and (18)F-FDG. RESULTS: In the subgroup of HCC patients with the number of lesions < or = 3 (32 patients; 55 lesions; mean size +/- SD, 3.5 +/- 1.9 cm), the sensitivity of detection by (11)C-acetate is 87.3% ((11)C-acetate maximum SUV [SUV(max)] = 7.32 +/- 2.02, with a lesion-to-normal liver ratio of 1.96 +/- 0.63), whereas the sensitivity of detection by (18)F-FDG is only 47.3%, and 34% lesions show uptake of both tracers. None of the lesions was negative for both tracers (100% sensitivity using both tracers). In some lesions and in the subgroup of HCC patients (n = 7) with multifocal or diffuse disease, dual-tracer uptake by different parts of the tumor is demonstrated. Histopathologic correlation suggests that the well-differentiated HCC tumors are detected by (11)C-acetate and the poorly differentiated types are detected by (18)F-FDG. All 16 non-HCC malignant (cholangiocarcinoma and metastatic) liver lesions do not show abnormal (11)C-acetate metabolism. Of the benign liver lesions, only FNH shows mildly increased (11)C-acetate activities ((11)C-acetate SUV(max) = 3.59, with a lesion-to-normal liver ratio of 1.25). CONCLUSION: (11)C-Acetate has a high sensitivity and specificity as a radiotracer complementary to (18)F-FDG in PET imaging of HCC and evaluation of other liver masses.     

18氟-脱氧葡萄糖和11碳-乙酸PET/CT显像在原发性肝癌及肝脏肿瘤样病变诊断中的初步研究

目的探讨18氟-脱氧葡萄糖(18 F-fluorodexyoxyglucose,18F-FDG)和11碳-乙酸(11 C-acetate,11 C-ACT)PET/CT显像在原发性肝癌及肝脏肿瘤样病变诊断中的作用。方法回顾性分析9例患者资料,其中男性7例,女性2例,平均年龄70.2岁,所有患者均为肝内单发病灶。治疗前均先行18 F-FDG PET/CT,后行11 C-ACT PET/CT检查,两次检查间隔时间不超过1周。其中有7例肝细胞肝癌(hepatocelluar carcinoma,HCC)、1例胆管细胞癌(cholangiocarcinoma,CCC)、1例肝内感染性病灶,均经病理学或临床随访证实。结果 7例HCC患者18 F-FDG PET/CT显像均为阴性,11 C-ACT PET/CT显像有6例为阳性。18F-FDG PET/CT和11 C-ACT PET/CT显像均未发现1例高分化胆管细胞癌。对于1例肝内炎性病灶,18F-FDG PET/CT显像为阳性,而11 C-ACT PET/CT显像为阴性。结论①11 C-ACT PET/CT显像可以用来探测那些呈18 F-FDG等或低摄取的HCC病灶;②对于高分化的CCC,18 F-FDG PET/CT显像有可能会表现为假阴性结果;③11 C-ACT PET/CT显像可以用来诊断肝内感染性病灶。     

Reduced oxidative metabolic response in dysfunctional myocardium with preserved glucose metabolism but with impaired contractile reserve.

The recovery of function in myocardium defined as viable by (18)F-FDG PET may differ from that defined by dobutamine stress echocardiography (DSE). The aim of this study was to investigate the difference in the oxidative metabolic response between myocardial segments with preserved contractile reserve (CR) and those without CR, in segments with and without preserved glucose metabolism (GM), using (11)C-acetate PET. METHODS: Twenty patients with previous myocardial infarction (left ventricular ejection fraction, 37.1% +/- 16.5%) underwent dynamic (11)C-acetate PET at rest and during dobutamine (7.5 microg/kg/min) infusion. GM was evaluated using (18)F-FDG PET and CR was evaluated using DSE. Dysfunctional segments were divided into 3 groups: group A (n = 26) with preserved CR and GM, group B (n = 15) without CR but with preserved GM, and group C (n = 41) without CR and without preserved GM. RESULTS: Resting oxidative metabolism (k mono = monoexponential clearance rate) was preserved in group A and group B (0.052 +/- 0.011/min vs. 0.051 +/- 0.012/min, P = not significant) but was reduced in group C (0.040 +/- 0.015/min) (P < 0.03 vs. group A and group B). The change in k mono, as a measure of the metabolic response to low-dose dobutamine, was significantly higher in group A (0.018 +/- 0.012) than that in group B (0.0075 +/- 0.0096, P < 0.03) and group C (0.0080 +/- 0.012, P < 0.005). CONCLUSION: Viable segments based on (18)F-FDG PET have preserved resting oxidative metabolism. However, segments without CR but with preserved GM show a reduction in the oxidative metabolic response to low-dose dobutamine infusion. The decrease in CR may be related to the reduction in the metabolic response to inotropic stimulation despite preservation of tissue viability on (18)F-FDG PET.     

Incidental finding of an <Superscript>11</Superscript>C-acetate PET-positive multiple myeloma

Multiple myeloma is a malignancy of plasma cells. The ¹⁸F-FDG PET findings of multiple myeloma have been reported previously. However, the ¹¹C-acetate PET findings have not been clarified. Here, we report a case of multiple myeloma detected with ¹¹C-acetate PET in a 51-year-old male patient with known hepatocellular carcinoma. The patient was admitted for management of a pathologic fracture of the right tibia. Imaging workup including X-ray, magnetic resonance image, bone scintigraphy; ¹⁸F-FDG led to a suspicion of metastatic bony lesions. Further, these lesions showed increased uptake on ¹¹C-acetate PET. Wide excision of the right tibia was performed, and histopathological examination of the lesion confirmed multiple myeloma. This case illustrates the characteristic ¹¹C-acetate PET findings of multiple myeloma.