多示踪剂PET/PET-CT 显像在肺癌诊断中的价值

肺癌是最常见的恶性肿瘤之一,早期诊断对病人预后及治疗方案的选择至关重要.PET-CT 目前已成为评价肺癌病人的重要影像检查方法,最常用的示踪剂为FDG.但FDG PET-CT 对于葡萄糖摄取低的肿瘤容易导致假阴性诊断,而在伴有感染性病变的病人则易导致假阳性诊断.近年来,新型的PET 示踪剂已广泛应用于临床,有效弥补了FDG PET-CT 对肺癌评价的不足.对多种示踪剂PET/PET-CT 在肺癌诊断和鉴别诊断方面的价值作一综述.     

多示踪剂PET/PET-CT显像在肺癌诊断中的价值

肺癌是最常见的恶性肿瘤之一,早期诊断对病人预后及治疗方案的选择至关重要。PET-CT目前已成为评价肺癌病人的重要影像检查方法,最常用的示踪剂为FDG。但FDGPET-CT对于葡萄糖摄取低的肿瘤容易导致假阴性诊断,而在伴有感染性病变的病人则易导致假阳性诊断。近年来,新型的PET示踪剂已广泛应用于临床,有效弥补了FDGPET-CT对肺癌评价的不足。对多种示踪剂PET/PET-CT在肺癌诊断和鉴别诊断方面的价值作一综述。     

双时相18F-FDG PET在肿瘤良恶性鉴别诊断中的应用

18F-FDG PET已较广泛地用于对恶性肿瘤的诊断和临床分期.常规显像一般用单次显像所测SUV(标准化摄取值)来鉴别良恶性病变,但两者SUV之间有一定交叉,存在一定局限性.而依据不同类型细胞18F-FDG摄取速率不同的机制,进行双时相18F-FDG PET(早期显像加延迟显像),简单而实用,具有较高的灵敏度、特异性和准确性.     

18F-FDG PET诊断肿瘤应考虑的几个问题

18F-FDG(18F-氟代脱氧葡萄糖)为非特异性肿瘤显像剂,熟悉与了解18F-FDG的正常分布与生理性变异、假阳性和假阴性、放疗和化疗对18F-FDG摄取的影响、血葡萄糖水平对肿瘤摄取18F-FDG的影响及肿瘤定位的局限性等,可提高18F-FDG诊断肿瘤的准确率,更好发挥18F-FDG在肿瘤应用中的独特优势。     

PET在头颈部肿瘤的应用

ET检查在头颈部肿瘤的原发和转移灶诊断中发挥重要的作用,尤其是在肿瘤治疗的评价方面,通过图像融合技术有助于其临床推广应用。     

18F氟代脱氧葡萄糖PET-CT在头颈部肿瘤中的应用价值

PET-CT能对恶性肿瘤病灶进行准确定位,在头颈部肿瘤的诊断、定位及指导临床治疗方面与单纯PET相比具有明显的优势.PET和CT优势互补,有助于进一步提高诊断及分期的准确性和可信度,有助于鉴别正常生理性摄取、炎症和恶性肿瘤,同时可以更好地指导临床精确放疗.18F-氟代脱氧葡萄糖（18F-FDG）PET-CT在大多数头颈部恶性肿瘤的诊断方面虽然有明显的优越性,但在甲状腺和腮腺病灶的良恶性鉴别、急性炎症与肿瘤的鉴别等方面仍有不足.     

胸腺上皮性肿瘤成像的研究现状及进展

胸腺上皮性肿瘤(TET)在临床工作中相对常见,尤其是自开展低剂量肺癌筛查以来,其发现越来越多。TET的生物学行为及病理学分型复杂,不同类型侵袭性程度不同,导致在制定临床治疗策略和预后评估上存在差异。因此,准确预测TET的侵袭性,甚至病理分型,对于临床有重要意义。多种影像检查手段能够发现TET,并各具优势,就其各自的诊断价值,尤其是新进展情况予以综述。     

骨骼和软组织肿瘤18F-FDG PET的应用进展

18F-FDG(18F-氟代脱氧葡萄糖)PET在肿瘤学领域已经得到了深入研究和广泛应用,尽管有关骨与软组织肿瘤的研究报告相对较少,但是近年来陆续发表的有关文献内容已涉及骨与软组织肿瘤病变良恶性鉴别、肿瘤恶性程度判断、治疗反应监测、肿瘤复发评价和骨转移肿瘤探测等诸多方面.     

PET-CT在卵巢癌中的临床应用价值

卵巢癌是妇科较常见的恶性肿瘤及致死原因,正电子发射体层显像（PET）对于卵巢癌的诊断、分期、复发及疗效监测及预后方面优于常规的检测手段（CT、MRI及肿瘤标志物检查）;PET-CT对指导手术有重要价值;特异性PET显像剂的研制已取得初步成果,124I-C6.5 diabody已经成功用于动物的PET-CT.     

放射性示踪剂正电子发射体层照相术在诊断淋巴瘤中的应用

淋巴瘤是原发于淋巴系统的恶性肿瘤,也称恶性淋巴瘤（malignant lymphoma ML）,分为霍奇金淋巴瘤（hodgkin’s lymphoma HL）和非霍奇金淋巴瘤（non-Hodgkin’s lymphoma NHL）两大类。ML多以进行性淋巴结肿大为特征,其治疗方法、疗效和预后等与肿瘤分型和分期等密切相关,因此,早期确诊对治疗和预后均有重要意义。放射性示踪剂正电子发射体层照相术（^18FDG—PET）对ML的诊断、分期及预后等均有较高价值。现综述如下。     

18F-氟脱氧葡萄糖PET在恶性淋巴瘤中的应用

CT是诊断恶性淋巴瘤常规影像学手段,核医学显像也是非常重要的检查方法,如67Ga显像.18F-氟脱氧葡萄糖(18SF-FDG)PET以其在淋巴瘤中应用的显著优势逐步替代了67Ga显像.18F-FDG PET在淋巴瘤的早期诊断、准确分期、疗效的评价、复发和预后的估计等方面显示出了非常重要的价值.随着PET-CT的广泛应用使得敏感性和特异性都有了进一步的提高.主要综述了18F-FDG PET在淋巴瘤诊断、分期、疗效评价中的应用.     

18F-FDG PET显像在胰腺恶性病变鉴别诊断及转移灶探查中的应用价值

目的研究18F-FDGPET显像在胰腺恶性肿瘤诊断与鉴别诊断中的应用价值。方法 40例临床疑为胰腺恶性病变的患者均行18F-FDGPET显像,对显像结果进行目测法及SUV值半定量分析,并结合CT,MRI等影像学检查进行综合诊断,最后诊断根据手术病理或经4个月以上随访证实。结果如果以SUV为2.5作为鉴别诊断胰腺病灶良恶性的阈值,24例证实为胰腺癌患者中18F-FDGPET显像正确诊断22例,16例胰腺良性病变患者18F-FDGPET检出13例,其灵敏度、特异度及准确性分别为91.7%（22/24）,81.3%（13/16）及87.5%（35/40）;而结合CT,MRI等其他检查结果进行综合诊断,其诊断灵敏度、特异度及准确性分别为91.7%（22/24）、87.5%（14/16）及90%（36/40）。恶性病变的SUV平均值为4.6±2.6,良性病变的SUV平均值为2.3±1.5,良恶性病变间SUV平均值差异有统计学意义（P〈0.01）。在转移灶的检出中,18F-FDGPET显像发现了全部38处转移灶,并发现6处CT,MRI未能发现的远处转移病灶,排除了1例CT认为是胰周转移性淋巴结肿大的病例。结论 18F-FDGPET对鉴别诊断胰腺良恶性肿瘤的灵敏度、特异性较高,尤其在远处转移灶的探查中有较高应用价值。     

放射性核素标记的胆碱在PET/CT肿瘤显像中的应用

18F-FDG PET/CT可明显提高恶性肿瘤诊断的准确性,指导恶性肿瘤的分期与再分期,对患者治疗方案的选择产生了重要影响。其在全身许多肿瘤中的应用价值已获得认可,但还存在一些不足。随着正电子标记药物的不断研发,放射性核素标记的胆碱逐渐应用于临床。胆碱是细胞膜的重要组成成分,恶性肿瘤的胆碱代谢增高。近年来的研究表明,胆碱PET/CT在胶质瘤、头颈部肿瘤、肺癌、肝细胞肝癌、前列腺癌、膀胱肿瘤等的诊断、分期及复发检测等方面具有很好的应用价值,特别是对颅内病变的观察、高分化肝细胞肝癌的诊断、生物靶区勾画、复发病灶的定位等,在一定程度上弥补了18F-FDG PET/CT的不足。笔者回顾了放射性核素标记的胆碱（11C-胆碱和18F-胆碱）在肿瘤显像中的应用。     

Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

Purpose

Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases.

Methods

Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85 ± 13 min after ¹⁸F-FDG injection of 403 ± 45 MBq) and then (125 ± 19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison.

Results

Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64 ± 0.70; in-phase, 1.29 ± 1.01; opposed-phase, 1.29 ± 1.15; water-weighted, 1.71 ± 1.07; fat weighted, 0.56 ± 1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63 ± 1.62; SUVmax, 4.30 ± 2.88) and contrast-enhanced PET/CT (SUVmean, 3.88 ± 2.30; SUVmax, 6.53 ± 4.04) in PET-positive lesions (SUVmean, ρ = 0.93; SUVmax, ρ = 0.95), although hybrid PET/MR presented a decrease of SUVs compared with contrast-enhanced PET/CT (mean reduction; SUVmean, 32.44 ± 15.64 %; SUVmax, 35.16 ± 12.59 %).

Conclusions

Despite different attenuation correction approaches, the SUV of PET-positive lesions correlated well between hybrid PET/MR and contrast-enhanced PET/CT. However Dixon MR images acquired for attenuation correction were insufficient to provide anatomic information of PET images because of low spatial resolution. Thus, additional MR sequence with fast and higher resolution may be necessary for anatomic information.     

FDG PET imaging for grading and prediction of outcome in chondrosarcoma patients

The aims of this study were to assess the potential of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) for tumor grading in chondrosarcoma patients and to evaluate the role of standardized uptake value (SUV) as a parameter for prediction of patient outcome. FDG PET imaging was performed in 31 patients with chondrosarcoma prior to therapy. SUV was calculated for each tumor and correlated to tumor grade and size, and to patient outcome in terms of local relapse or metastatic disease with a mean follow-up period of 48 months. Chondrosarcomas were detectable in all patients. Tumor SUV was 3.38±1.61 for grade I (n=15), 5.44±3.06 for grade II (n=13), and 7.10±2.61 for grade III (n=3). Significant differences were found between patients with and without disease progression: SUV was 6.42±2.70 (n=10) in patients developing recurrent or metastatic disease compared with 3.74±2.22 in patients without relapse (P=0.015). Using a cut-off of 4 for SUV, sensitivity, specificity, and positive and negative predictive values for a relapse were 90%, 76%, 64%, and 94%, respectively. Combining tumor grade and SUV, these parameters improved to 90%, 95%, 90%, and 95%, respectively. Pretherapeutic tumor SUV obtained by FDG PET imaging was a useful parameter for tumor grading and prediction of outcome in chondrosarcoma patients. The combination of SUV and histopathologic tumor grade further improved prediction of outcome substantially, allowing identification of patients at high risk for local relapse or metastatic disease.     

PET/MRI在肿瘤研究中的新进展

PET/MRI成像整合了PET提供的人体生理代谢、分子信息和MRI提供的功能、解剖形态信息,在肿瘤诊断、评估肿瘤生物学行为(包括分期、分级、浸润深度、远处转移)、评价治疗疗效及预后方面具有较高的准确性、敏感性、特异性,实现了PET及MR成像设备的优势互补。就PET/MRI在肿瘤中的应用现状及其发展前景进行回顾和展望。     

靶向CXCR4 PET/CT分子探针在肿瘤诊疗中的应用进展

趋化因子受体4（CXCR4）在许多肿瘤细胞表面高表达,它可以作为肿瘤干细胞的标志物,其表达与肿瘤的恶性程度及病人的预后直接相关。靶向CXCR4 PET/CT显像在疾病的诊断、CXCR4靶向治疗病例选择、疗效评价等方面具有很大的应用潜力。就靶向CXCR4 PET/CT分子探针及其在肿瘤诊疗中的应用研究进展进行综述,总结分析各种探针的特点及临床转化情况,为CXCR4临床应用转化提供帮助。     

Clinical usefulness of F-18 FDG PET in lymphoepithelioma-like gastric carcinoma

PurposeLymphoepithelioma-like carcinoma (LELC) is a rare type of gastric cancer. We evaluated the clinical usefulness of F-18 FDG positron emission tomography/computed tomography (PET/CT) in LELC of stomach.Materials and methodsA total of 28 patients (mean age = 59 years) who underwent preoperative F-18 FDG PET/CT were enrolled retrospectively. Nine patients underwent follow-up F-18 FDG PET/CT. Pathologic information was obtained through gastrectomy and the association with Epstein-Barr virus (EBV) was investigated in 26 patients.ResultsPET/CT detected 85.0% (17/20) of advanced gastric cancers (AGC) and 12.5% (1/8) of early gastric cancers (EGC). Most tumors (23/26, 88.5%) were EBV-associated. The maximum standardized uptake value of FDG-avid tumors was 7.5 ± 3.0. The sensitivity and specificity of PET/CT for the presence of lymph node metastasis was 47.8% (11/23) and 100.0% (13/13), respectively. PET/CT also detected a hepatic sarcomatoid carcinoma in one patient. The specificity of PET/CT for distant metastasis or second malignancy was 96.3%. Follow-up PET/CT detected malignant lesions in 3 of 9 patients; a liver metastasis, recurrent hepatic sarcomatoid carcinomas and a metachronous cholangiocarcinoma. PET/CT correctly excluded recurrence in the rest of the patients (6/6). The sensitivity and specificity of PET/CT for detecting recurrence or second malignancy was 100% and 100%, respectively.ConclusionF-18 FDG PET/CT would be a useful tool in evaluating distant metastasis or recurrence in patients with gastric LELC.     

创伤性脑损伤PET显像研究进展

创伤性脑损伤(TBI)是由外伤引起的脑组织损害,有着较高的发生率及病死率.传统医学影像学技术难以做出诊断.PET作为一种定量测定脑糖代谢及脑血流量变化的显像技术,可以比较精确地显示TBI所致的脑功能变化.目前,18F-FDG PET显像通过评价脑内葡萄糖代谢及脑血流量变化对TBI做出诊断.笔者对TBI18F-FDG PET显像及脑血流灌注显像进行综述.     

PET-CT在恶性肿瘤诊断中的初步应用

目的探讨PET-CT一体机在恶性肿瘤中的应用价值.方法收集已经明确诊断的全身不同部位的恶性肿瘤病例62例,经PET-CT检查后进行回顾性分析,采用目测和半定量分析方法.结果62例肿瘤病人共检出142个病灶,PET图像阳性率93.55%(58/62);PET图像阴性率6.45%(4/62);PET发现病灶而CT未完全发现病灶率19.4%(12/62);CT发现而PET未见浓聚率6.45%(4/62);原发灶未能找到率1.61%(1/62).标准化摄取值(SUV)大于2.5占78.2%(111/142);SUV2.5～2.0占14.8%(21/142);SUV小于2.0占7%(10/142).结论PET-CT与单纯PET,CT比较具有明显的优势,可以精确定位、定性,但PET-CT也有一定的局限性.