^18F-FDG PET／CT在胰腺癌诊断中的价值

目的评价^18F-脱氧葡萄糖（FDG）PET／CT鉴别诊断胰腺良恶性病变及检测淋巴结和（或）远处转移的价值。方法回顾性分析上海交通大学医学院附属仁济医院行^18F—FDGPET／CT检查的46例临床疑胰腺肿瘤患者的影像学检查资料和临床资料,其中胰腺癌患者26例,良性病变者20例,比较分析PET和CT的特征。结果当选择最大标准摄取值（SUVmax）=2．95为判断良恶性的界值时,对胰腺癌诊断的灵敏度是88．5％（23／26）,特异性是85．0％（17／20）。^18F—FDGPET／CT显像假阳性3例,假阴性3例。同时发现16例检查前未确定的肝、肺、骨及淋巴结转移患者。根据显像结果,11例患者治疗方案得以修正。结论根据现有资料分析,^18F—FDGPET／CT是鉴别诊断胰腺良恶性病变及检测胰腺癌患者淋巴结和（或）远处转移一种较好的方法。     

FDG PET对肿瘤的评估价值

正电子发射体层(PET)是一种能够识别肿瘤内生化、生理变化的诊断影像技术，FDGPET可明显提高肿瘤诊断的准确性。肿瘤的FDG摄入量是与其内对葡萄糖需求量增加的有增殖能力的肿瘤细胞的代谢率呈正比的。FDG PET在肿瘤应用方面，对肿瘤的分期、分型，复发、转移的早期诊断，坏死与存活组织的鉴别，肿瘤生物特征的预测，及治疗反应的监测作用都得到了广泛承认。     

18F-FDG PET-CT显像在肺癌诊断分期与定位中应用的初步研究

目的 :探讨18F 脱氧葡萄糖 (FDG)进行正电子发射计算机扫描与CT扫描融合显像 (PET CT)对肺癌诊断、定位与分期的价值。方法 :对经临床或其他显像等相关方法证实的 2 6例患者进行18F FDGPET CT显像 ,其中肺恶性病变 15例 ;良性病变 11例 (肺结核 6例 ,肺炎 5例 )。分析其CT影像学特点 ,包括病灶大小、形态、密度、CT值、与周围组织的关系。利用CT对PET进行衰减校正 ,并对相应位置PET影像的代谢情况分析 ,测定其标准摄取值SUV值。对良、恶性病变的SUV值进行比较。通过CT与PET图像融合 ,对病灶进行准确地诊断与定位。结果 :15例恶性肿瘤中 14例PET CT阳性 ,其中纵膈淋巴结转移者 6例 ,最小淋巴结大小为 0 .7cm× 0 .5cm ,骨转移者 3例。 11例良性肺显像中 8例为阴性 ,3例放射性摄取轻度增高。结论 :18F FDGPET CT显像对肺良、恶性病变的诊断有一定的临床价值 ,对病灶的形态学特点及准确定位更为突出。     

~(18)F-FDG PET显像在胰腺癌诊断中的临床应用

目的 :探讨18F FDGPET显像在胰腺癌诊断中的应用价值。方法 :5 4例临床怀疑为胰腺癌的患者均行18F FDGPET显像 ,对显像结果进行目测法及半定量分析 ,并与CT、手术、腹腔镜取病理等进行对比研究。结果 :18F FDGPET显像对胰腺癌诊断的敏感度为 93 % ( 3 8/4 1) ,特异度为 85 % ( 11/13 )。CT对胰腺癌诊断的敏感度为 76% ( 3 1/4 1) ,特异度为 69% ( 9/13 )。18F FDGPET显像发现 7例CT检查未能确定的肝、肺及淋巴结转移 ,同时PET诊断结果使 15例( 2 8% )患者的临床治疗方案得到修正。结论 :18F FDGPET显像对胰腺癌的诊断及临床分期具有较好的临床应用价值。     

双时相18F-FDG PET/CT显像在胰腺良恶性病变鉴别诊断中的应用

目的 探讨双时相18F-FDG PET/CT对胰腺良恶性病变鉴别诊断的价值.方法 回顾性分析2011年9月～2012年6月在我院行双时相18F-FDG PET/CT全身检查的胰腺病变患者41例,分别测定病灶早期及延迟标准摄取值（SUVmax）,计算18F-FDG的滞留指数（retention index,RI）;以病理及临床随访结果作为诊断标准,绘制SUVmax早期及RI的ROC曲线,寻找最佳诊断界值,分别计算SUVmax早期、RI为标准诊断胰腺癌敏感性、特异性及准确性.结果 41例胰腺病变患者中,恶性组（26例）SUVmax早期、SUVmax延迟、RI分别为8.2±2.7、10.5±4.1、（24.1±22.6）％,良性组（15例）SUVmax早期、SUVmax延迟、RI分别为4.0±3.7、4.3±3.8、（8.5±14.1）％;胰腺恶性病变SUVmax延迟较SUVmax早期明显升高（P＜0.001）,胰腺良性病灶延迟显像前后SUVmax差异无统计学意义（P=0.068）,胰腺良恶性组间RI差异有统计学意义（P=0.004）.本试验根据ROC曲线观察发现以SUV max=3.4为界值,诊断胰腺癌的敏感性、特异性及准确性分别为92.3％、66.7％、82.9％;以RI=9.1％为界值,诊断胰腺癌的敏感性、特异性及准确性分别为76.9％、73.3％及73.2％;SUVmax≥3.4结合RI≥9.1％诊断胰腺癌敏感性、特异性及准确性分别为88.5％、86.7％及87.8％.结论 应用双时相18F-FDG PET/CT显像能提高胰腺癌诊断特异性及准确性,但炎性（包括肿块型胰腺炎、自身免疫性胰腺炎、结核）延迟显像也可明显升高.     

PET/CT对胰腺癌诊断现状及进展

胰腺癌是一种常见的消化系统恶性肿瘤,其预后差,早期诊断具有重要的意义。18F-FDG PET/CT集功能影像与解剖成像于一体,能够反映肿瘤组织的代谢和细胞增生水平,以及肿瘤组织与周围结构的毗邻关系,因此在胰腺癌患者的诊断、分期、指导治疗、疗效监控和预后评价等方面具有较为明显的优势。本文就18F-FDG PET/CT在胰腺癌临床应用中的价值进行综述。     

18F-FDG PET-CT与增强CT在胰腺病变良恶性鉴别及胰腺癌分期中的价值对比研究

目的 探讨18 F-FDG PET/CT与增强CT(CECT)在胰腺良恶性病变鉴别及胰腺癌分期中的价值.方法 回顾性分析治疗前在我院行CECT和PET/CT检查的胰腺病例(时间间隔≤2周),并以病理及临床影像随访结果作为金标准,比较CECT、PET/CT对胰腺病变良恶性鉴别诊断以及胰腺癌TNM分期的灵敏度、特异度及准确率.结果 共入选病例68例,其中男43例,女25例,恶性48例,良性20例.良性病变组SUVmax平均5.06(范围1.10～29.10),恶性病变组SUVmax平均7.80(范围1.60～17.60).CECT与最终诊断有中度一致(κ=0.414,P＜0.05);PET/CT与最终诊断有较高度的一致性(κ=0.677,P ＜0.05).术前CECT和PET/CT诊断胰周血管侵犯的灵敏度、特异度、准确率分别为(92.9％、93.3％、93.1％)vs(21.4％、93.3％、58.6％).CECT和PET/CT诊断区域淋巴结转移的灵敏度、特异度、准确率分别为(64.7％、91.7％、75.9％)vs(76.5％、83.3％、79.3％).CECT和PET/ CT诊断远处转移的灵敏度、特异度、准确率分别为(58.8％,100％,85.4％)vs(88.2％,96.8％,93.7％).结论 PET/CT在胰腺恶变的诊断中具有更高的敏感性和特异性,对远处转移的有更高的敏感性;而CECT可以精确地显示肿瘤与血管的关系、对远处转移的有更高的特异性,两者各有优势不能相互取代,临床工作中需要我们根据患者的实际情况合理选择,必要时联合应用,更好地发挥它们的优势.     

18F-FDGPET／CT联合腹部增强CT对诊断胰腺癌及评估肿瘤可切除性的临床应用

目的评价18F-脱氧葡萄糖（FDG）PET／CT联合腹部增强CT对诊断胰腺癌、鉴别诊断胰腺良恶性病变以及评估肿瘤可切除性的临床应用价值。方法回顾性分析行18F—FDGPET／CT和腹部增强CT检查并经病理检查或临床等方法证实的48例原发性胰腺病变患者的资料,其中胰腺癌34例,胰腺良性病变14例。对胰腺癌和胰腺良性病变患者最大标准摄取值（SUVmax）进行t检验;比较分析单独PET、腹部增强CT、PET／CT、PET／CT联合腹部增强CT4种方法的图像特征和诊断价值,对灵敏度和准确性进行x2检验,对特异性进行Fisher确切概率法检验。结果34例胰腺癌患者与14例胰腺良性病变患者的SUVmax（5．91±2．90和2．24±1．13）差异有统计学意义（t=4．56,P〈0．01）。PET／CT联合腹部增强CT诊断胰腺癌的灵敏度、特异性和准确性分别为97．1％（33／34）、92．9％（13／14）和95．8％（46／48）,与单纯PET的88．2％（30／34）、64．3％（9／14）和81．2％（39／48）相比,x2=0．863和P=0．352,P=0．038,X2=5．031和P=0．024;与腹部增强CT的76．5％（26／34）、71．4％（10／14）和75．0％（36／48）相比,x2=6．274和P=0．012,P=0．042,x2=8．362和P=0．003;与PET／CT的88．2％（30／34）、78．6％（11／14）和85．4％（41／48）相比,x2=0．863和P=0．352,P=0．048,x2=3．928和P=0．047。PET／CT全身显像几乎发现了全部转移灶,使14例胰腺癌患者避免了不必要的外科手术;PET／CT可对单独PET显像诊断的胰腺癌患者胰腺外假阳性病灶进行正确诊断,使1例胰头癌患者分期下调,进行了外科手术。腹部增强CT通过多期显像,可以准确判断肿瘤对胰腺周围主要血管的侵犯程度,腹部增强CT按血管受侵程度评估肿瘤可切除性的准确性为83．3％（15／18）,不可切除的准确性为9／9。结论PET／CT联合增强CT对于诊断胰腺癌、鉴别胰腺良恶性病变及评估肿瘤的可切除性准确性有一定临床价值。     

18F-FDG PET/CT结合高分辨率CT对孤立性肺结节的诊断价值

目的探讨^18F-脱氧葡萄糖（FDG）PET／CT结合高分辨率CT（HRCT）对孤立性肺结节（SPN）的鉴别诊断价值。方法25例经手术病理检查或治疗随访证实的SPN（共27个）患者，同期行^18F—FDGPET／CT显像和病灶部位HRCT检查。^18F—FDGPET／CT用目测法结合半定量法判断良恶性。HRCT则根据病灶形态学特征判断良恶性。所得^18F—FDGPET／CT结果和^18F—FDGPET／CT与HRCT相结合结果分别与病理检查结果对照比较。结果27个SPN中15个恶性，12个良性。PET／CT正确诊断14个恶性和9个良性SPN。3个良性SPNPET／CT显像为阳性，其中2个经PET／CT和HRCT联合诊断为良性。联合诊断灵敏度和单纯PET／CT相同（93．3％），但特异性、阳性预测值、阴性预测值、准确性分别高于PET／CT（91．7％、93．3％、91．7％和93．7％对75．0％、82．4％、90．0％和85．2％）。结论^18F—FDGPET／CT结合HRCT是有效的无创性鉴别SPN良恶性的方法。     

18F-FDG PET显像在鉴别胰腺良恶性肿块中的应用价值

18F-氟代脱氧葡萄糖(18F-FDG)PET显像诊断和鉴别诊断胰腺良恶性肿块有较高的特异性、敏感性、阳性预测率和阴性预测率,并对胰腺癌有无肝、肺等远处和淋巴转移、治疗方案的确定和肿块切除后随访等有着重要的实际应用价值。     

18F-FDG PET/MRI在胰腺癌中的临床应用及新进展

胰腺癌是一种恶性程度高、易转移、进展快、预后差的恶性肿瘤,早期诊断、准确分期和及时的疗效评估对胰腺癌患者至关重要。一体化的PET/MRI作为一种新型的多模态成像技术,集合了MRI对软组织分辨率高、多序列、多参数和PET代谢显像的高灵敏度等优势,在胰腺癌患者的肿瘤分期、疗效评估、预后预测、复发监测等方面具有潜在的应用价值。因此,笔者就18F-氟脱氧葡萄糖（FDG）PET/MRI的优势及其在胰腺癌中的临床应用及新进展进行综述。     

Diagnosis of pancreatic cancer using fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) —Usefulness and limitations in “clinical reality”—

The present review will provide an overview of the literature concerning the FDG PET diagnosis of pancreatic cancer and a summary from our experience of 231 cases of pancreatic lesions. FDG PET can effectively differentiate pancreatic cancer from benign lesion with high accuracy. Newly-developed PET scanners can detect small pancreatic cancers, up to 7 mm in diameter, by their high resolution, which could make a great contribution to the early detection of resectable and potentially curable pancreatic cancers. FDG PET is useful and cost-beneficial in the pre-operative staging of pancreatic cancer because an unexpected distant metastasis can be detected by whole-body PET in about 40% of the cases, which results in avoidance of unnecessary surgical procedures. FDG PET is also useful in evaluation of the treatment effect, monitoring after the operation and detection of recurrent pancreatic cancers. However, there are some drawbacks in PET diagnosis. A relatively wide overlap has been reported between semiquantitative uptake values obtained in cancers and those in inflammatory lesions. As for false-positive cases, active and chronic pancreatitis and autoimmune pancreatitis sometimes show high FDG accumulation and mimic pancreatic cancer with a shape of focal uptake. There were 8 false negative cases in the detection of pancreatic cancer by FDG PET, up to 33 mm in diameter, mainly because of their poor cellularity in cancer tissues. In addition, there are 19% of cancer cases with a decline in FDG uptake from 1 hr to 2 hr scan. FDG PET was recently applied to and was shown to be feasible in the differential diagnosis of cystic pancreatic lesions, such as intraductal papillary mucinous tumor of the pancreas. Further investigations are required to clarify the clinical value of FDG PET in predicting prognosis of the pancreatic patients.     

Fluorodeoxyglucose positron emission tomography excludes pericardial metastasis by recurrent lung cancer

Fluorodeoxyglucose (FDG) positron emission tomography (PET) has been shown to be useful in the diagnosis and staging of a variety of malignancies. Because of its high sensitivity, FDG PET frequently detects malignant lesions that are not demonstrated clearly by anatomic imaging modalities. FDG PET usually has high negative predictive value and, therefore, negative studies are highly suggestive of a benign process. The authors present a patient in whom transesophageal echocardiography and magnetic resonance imaging described pericardial metastasis from a recurrent lung cancer, which on FDG PET was shown correctly to suggest benign scar tissue.     

Pancreatic metastasis detected by F-18 FDG PET/CT in a patient with breast cancer

Pancreatic involvement by metastasis from other primaries is rare and accounts for approximately 2% to 4% of pancreatic tumors. In this article, we describe FDG-avid pancreatic involvement in a patient with diagnosis of breast cancer. We conclude that FDG PET can be a convenient noninvasive method of early detection of recurrence and in monitoring metastatic disease during follow-up in such patients. A positive FDG PET warrants histopathologic correlation for appropriate treatment.     

Ki-67 immunostaining in pancreatic cancer and chronic active pancreatitis: does in vivo FDG uptake correlate with proliferative activity?

PET with 18F-FDG has been shown to be useful in the detection and staging of pancreatic cancer. However, whether FDG uptake is dependent on proliferative activity is still unclear. The aim of this prospective study was to evaluate a probable correlation between FDG uptake and proliferative activity in benign and malignant pancreatic tumors. METHODS: Our series consisted of 23 patients with pancreatic cancer and 9 patients with chronic active pancreatitis (CAP). FDG PET was performed within 2 wk before surgery, and standardized uptake values (SUVs) were calculated for benign and malignant pancreatic tumors. Patients were selected when focally increased FDG uptake in previously known pancreatic tumors was present. Proliferation fraction was measured in tissue specimens using the anti-Ki-67 antibody MIB-1. A computer-assisted imaging system was used for quantification of nuclear Ki-67 immunostaining. Immunohistochemical findings were correlated to SUVS: RESULTS: Pancreatic cancer showed both intense nuclear staining of Ki-67 (39% +/- 16%) and high FDG uptake (SUV = 3.6 +/- 1.6). However, no significant correlation was found between in vivo FDG uptake and Ki-67 immunoreactivity (P = 0.65). By contrast, Ki-67 nuclear staining was significantly lower (3.8% +/- 2.7%, P < 0.05) in CAP, whereas FDG uptake was in the same range as for pancreatic cancer (SUV = 3.5 +/- 1.8). CONCLUSION: FDG uptake did not correlate with proliferative activity in pancreatic cancer. Proliferative activity was tenfold higher in malignant pancreatic tumors than in benign tumors associated with CAP, whereas FDG uptake in vivo did not differ significantly. Thus, a PET tracer indicating cellular proliferation should better differentiate between cancer and inflammatory lesions than do metabolic markers such as FDG.     

Present status of PET images: clinical FDG PET in oncology

The clinical application of positron emission tomography with fluorodeoxyglucose (FDG PET) in the field of cancer diagnosis is expanding rapidly. FDG PET has been proven to be a clinically useful tool for the detection and staging of malignant tumors, differentiation of mass lesions, and follow-up and monitoring of malignant diseases after treatment. Several factors relating to the clinical spread of FDG PET, including the simplification of FDG production, establishment of an FDG delivery system, shortening of the data acquisition time for whole body imaging, development of a coincidence gamma camera, and reimbursement from medical insurance, are reviewed and discussed in this article. PET oncology currently has greater potential as a result of the development of new radiopharmaceuticals based on the tumor characteristics of biochemical and genetic processes. The recent development of clinical FDG PET might be simply a stepping stone for the development of more advanced PET oncology in the near future.     

Evaluation of delayed additional FDG PET imaging in patients with pancreatic tumour

AIM: To evaluate whether delayed fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging is more helpful in differentiating between malignant and benign lesions and whether delayed FDG PET imaging can identify more lesions in patients in whom pancreatic cancer is suspected. METHODS: The study evaluated 86 patients who were suspected of having pancreatic tumours. FDG PET imaging (whole body) was performed at 1 h (early) post-injection and repeated 2 h (delayed) after injection only in the abdominal region. Qualitative and semi-quantitative evaluation was performed. The semi-quantitative analysis was performed using the standardized uptake value (SUV), obtained from early and delayed images (SUVearly and SUVdelayed, respectively). Retention index (RI) was calculated according to the equation: (SUVdelayed-SUVearly)x100/SUVearly. RESULTS: The final diagnosis was pancreatic cancer in 55 and benign disease in 31 patients. On visual and semi-quantitative analysis, the diagnostic accuracy of RI was the highest (88%). The differences between the SUVearly, SUVdelayed and RI value in both pancreatic cancer and benign disease were significant (P<0.01). The mean value of SUVdelayed was significantly higher than that of SUVearly (P<0.01) in pancreatic cancer. Furthermore, new foci of metastasis were seen in the liver in two patients and in the lymph node in one patient only on delayed images. CONCLUSIONS: The RI values obtained using early and delayed FDG PET may help in evaluating pancreatic cancer. Furthermore, addition of delayed FDG PET imaging is helpful to identify more lesions in patients with pancreatic cancer.     

Clinical PET in Oncology

The major utilization of clinical PET is in oncology, and oncologic PET utilizes FDG as the radiopharmaceutical. FDG imaging demonstrates the increased metabolism by malignant cells compared to normal cells. The initial clinical application of FDG-PET was demonstrated in brain tumors, and the gradation of accumulation of FDG related to the degree of malignancy. Subsequent studies have documented the accuracy of FDG-PET in detecting and staging several different malignancies. Whole-body imaging has made a major impact on the ability of PET to document the distribution of malignancy.FDG-PET imaging is very accurate in determining if an indeterminate solitary pulmonary nodule is malignant and in staging lung cancer. The cost-effectiveness of PET has been demonstrated for these indications. Third-party payers have policies for paying for PET scans performed in the evaluation of solitary pulmonary nodules and in staging lung cancer. The preliminary data on the use of FDG-PET imaging in other malignancies supports its use in detecting liver metastases from colorectal cancer and differentiating fibrosis from recurrent tumor after therapy for colorectal cancer; staging the axilla in primary breast cancer; staging melanoma and lymphoma; and staging and detecting recurrence of head and neck cancer. The initial reports on the use of FDG-PET are encouraging in its use in musculoskeletal malignancy, ovarian cancer, pancreatic cancer, and thyroid cancer.     

FDG PET positive lymph nodes are highly predictive of metastasis in breast cancer

AIM: To determine whether or not fluorodeoxyglucose positron emission tomography (FDG PET) imaging when positive could obviate the necessity for sentinel lymph node biopsy and for complete axillary node dissection in patients with breast cancer. METHODS: A total of 80 female patients with a histological diagnosis of breast cancer and clinically negative axillary nodes underwent an FDG PET and sentinel lymph node biopsy (SLNB) or total axillary dissection for staging of axilla. Both SLNB and axillary dissection were performed in 72 patients, while eight patients had total axillary dissection without SLN biopsy. RESULTS: Of the 80 patients, 36 had lymph node metastasis on histopathology. SLNB was positive for metastasis in 35 (97%) of 36 patients (29 macrometastasis and seven micrometastasis). In the patient with false negative SLNB, the lymph node was completely replaced by the tumour. The FDG PET was true positive in 16 of 36 patients (sensitivity, 44%). There were two false positive studies with FDG PET, resulting in a specificity of 95%. The positive predictive value and accuracy of FDG PET for the detection of axillary lymph node metastasis were 89% and 72%, respectively. Univariate analysis revealed that higher grade of tumour, increased size and number of axillary lymph nodes were significantly associated with positive FDG PET results for axillary staging. CONCLUSION: FDG PET cannot replace histological staging using SLNB in patients with breast cancer. However, FDG PET has a high specificity and positive predictive value for staging of the axilla in these patients. The patients with higher grade of tumour, larger size and higher number of axillary lymph nodes may be considered for FDG PET scan for axillary staging.     

Optimal interpretation of FDG PET in the diagnosis, staging and management of pancreatic carcinoma.

This study had two purposes: to optimize the semiquantitative interpretation of 18F-fluorodeoxyglucose (FDG) PET scans in the diagnosis of pancreatic carcinoma by analyzing different cutoff levels for the standardized uptake value (SUV), with and without correction for serum glucose level (SUV(gluc)); and to evaluate the usefulness of FDG PET when used in addition to CT for the staging and management of patients with pancreatic cancer. METHODS: Sixty-five patients who presented with suspected pancreatic carcinoma underwent whole-body FDG PET in addition to CT imaging. The PET images were analyzed visually and semiquantitatively using the SUV and SUV(gluc). The final diagnosis was obtained by pathologic (n = 56) or clinical and radiologic follow-up (n = 9). The performance of CT and PET at different cutoff levels of SUV was determined, and the impact of FDG PET in addition to CT on patient management was reviewed retrospectively. RESULTS: Fifty-two patients had proven pancreatic carcinoma, whereas 13 had benign lesions, including chronic pancreatitis (n = 10), benign biliary stricture (n = 1), pancreatic complex cyst (n = 1) and no pancreatic pathology (n = 1). Areas under receiver operating characteristic curves were not significantly different for SUV and SUV(gluc). Using a cutoff level of 3.0 for the SUV, FDG PET had higher sensitivity and specificity than CT in correctly diagnosing pancreatic carcinoma (92% and 85% versus 65% and 61%). There were 2 false-positive PET (chronic pancreatitis, also false-positive with CT) and 4 false-negative PET (all with true-positive CT, abnormal but nondiagnostic) examinations. There were 5 false-positive CT (4 chronic pancreatitis and 1 pancreatic cyst) and 18 false-negative CT (all with true-positive FDG PET scans) examinations. FDG PET clarified indeterminate hepatic lesions or identified additional distant metastases (or both) in 7 patients compared with CT. Overall, FDG PET altered the management of 28 of 65 patients (43%). CONCLUSION: FDG PET is more accurate than CT in the detection of primary tumors and in the clarification and identification of hepatic and distant metastases. The optimal cutoff value of FDG uptake to differentiate benign from malignant pancreatic lesions was 2.0. Correction for serum glucose did not significantly improve the accuracy of FDG PET. Although FDG PET cannot replace CT in defining local tumor extension, the application of FDG PET in addition to CT alters the management in up to 43% of patients with suspected pancreatic cancer.