Comparison of (11)C-choline PET/CT and enhanced CT in the evaluation of patients with pulmonary abnormalities and locoregional lymph node involvement in lung cancer

BackgroundThis study compares the diagnostic abilities of integrated ¹¹C-choline PET/CT imaging and contrast-enhanced helical CT imaging in pulmonary lesions and locoregional lymph node metastases in patients with lung cancer.Patients and MethodsOne hundred eight patients with proven or suspected lung cancer underwent integrated ¹¹C-choline PET/CT and contrast-enhanced CT, followed by surgical resection and nodal staging.ResultsThe ¹¹C-choline PET/CT and CT diagnoses of pulmonary lesions and locoregional lymph node metastases were compared with pathologic findings, which revealed benign lesions in 26 patients (tuberculoma [8 patients], inflammatory pseudotumor [7 patients], hamartoma [6 patients], sclerosing hemangioma [4 patients], and pulmonary sequestration [1 patient]) and lung cancers in 82 patients (adenocarcinoma [39 patients], squamous cell carcinoma [23 patients], carcinoid [7 patients], small-cell lung cancer [5 patients], adenosquamous carcinoma [5 patients], and large-cell lung cancer [3 patients]). The accuracy, sensitivity, and specificity of ¹¹C-choline PET/CT for diagnosing lung cancer were 82.4%, 85.4%, and 73.1%, respectively, compared with 73.1%, 76.8%, and 61.5%, respectively, for CT. Differences between ¹¹C-choline PET/CT and CT in diagnosing lung cancer were not statistically significant (p = .503, .118, and .375, respectively). We used receiver operating characteristic (ROC) curve for analysis, finding the ROC of standard uptake value (SUV_max) for diagnosing lung cancer. The cutoff value of SUV_max was 3.54. Preoperative nodal staging was compared with postoperative histopathologic staging. ¹¹C-choline PET/CT correctly staged 80.5% of patients, 12.2% were overstaged, and 7.3% were understaged; for CT these values were 58.5%, 24.4%, and 17.1%, respectively. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ¹¹C-choline PET/CT for lymph nodes were 83.8%, 82.4%, 84.1%, 50.3%, and 96.1%, respectively, compared with 69.3%, 63.7%, 71.2%, 30.2%, 91.0%, respectively, for CT.ConclusionDifferences in the accuracy, sensitivity, specificity, PPV, and NPV between ¹¹C-choline PET/CT and CT are thus statistically significant for nodal staging (p = .003, .007, .000, .000, and .004, respectively). Although ¹¹C-choline PET/CT is not significantly better at diagnosing pulmonary lesions than is enhanced CT, ¹¹C-choline PET/CT has improved sensitivity, specificity, accuracy, PPV, and NPV relative to enhanced CT in the evaluation of locoregional lymph nodes.     

~(18)F-FDG PET-CT与强化CT对非小细胞肺癌区域淋巴结诊断价值的评价

目的 探讨~(18)F-脱氧葡萄糖(FDG)PET-CT与强化CT对非小细胞肺癌(NSCLC)区域淋巴结的诊断价值.方法 随机选择手术治疗的NSCLC患者122例,术前2周内行PET-CT检查,同期行CT强化扫描,根据术后病理检查结果,评价PET-CT和CT诊断NSCLC区域淋巴结的价值.结果 PET-CT能对80.3%NSCLC患者的区域淋巴结正确分期,13.1%的患者分期过度,6.6%的患者分期过低,而CT分别为55.8%、26.2%和18.0%.PET-CT对NSCLC区域淋巴结诊断的敏感度、特异度和准确率分别为86.3%、85.0%和85.3%,CT分别为68.6%、71.0%和70.4%,二者差异有统计学意义(P<0.01).PET-CT能纠正CT出现的81.3%的假阴性和71.6%的假阳性淋巴结,CT能纠正PET-CT出现的57.1%的假阴性和45.2%的假阳性淋巴结.5.9%的病理阳性淋巴结内存在微小的癌灶且短径<10 mm,被PET-CT和CT均诊断为假阴性;8.2%的病理阴性淋巴结短径>10 mm(隆突下淋巴结>15 mm),存在炎症及高的FDG摄取,被PET-CT和CT均诊断为假阳性,这些淋巴结是二者共同的盲点.结论 与强化CT相比,PET-CT能提高NSCLC区域淋巴结诊断的准确率,并能纠正CT出现的假阳性和假阴性错误.CT对PET-CT也是一个有益的补充,二者联合应用能相互弥补在NSCLC区域淋巴结诊断中的不足.     

Accuracy of positron emission tomography in mediastinal node assessment in coal workers with lung cancer

The purpose of this study was to explore the accuracy of ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) in the assessment of mediastinal lymph node in coal workers who had non-small cell lung cancer. We retrospectively reviewed 42 retired coal workers who had lung cancer without distant metastasis, between May 2007 and May 2010. Regarding the mediastinal lymph nodes, when the standard uptake value was greater than 2.5, it was considered “malignancy positive.” After histological examination of the mediastinal lymph nodes, anthracotic and metastatic ones were detected. The results of PET/CT were analyzed to determine its accuracy. Of these 42 patients, PET/CT detected 47 positive mediastinal lymph nodes in 24 patients with a mean SUV maximum of 6.2 (2.6–13.8). One hundred and thirty-one mediastinal lymph node foci were dissected. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG-PET/CT in detecting nodal metastases were 84% (16/19), 65% (15/23), 66% (16/24), 83% (15/18), and 74% (31/42) on a per-patient basis, respectively. Mediastinal node staging with FDG-PET/CT in coal workers is insufficient due to the high false-positive rates due to the presence of pneumoconiosis. In these patients, an invasive technique such as mediastinoscopy seems mandatory for confirmation of ipsilateral or contralateral mediastinal lymph node metastasis.     

The role of PET scan in diagnosis, staging, and management of non-small cell lung cancer

Positron emission tomography (PET) is now an important cancer imaging tool, both for diagnosis and staging, as well as offering prognostic information based on response. This report attempts to comprehensively review the value of PET in the locoregional and distant staging of non-small cell lung cancer (NSCLC), illustrate the potential effects on patient management, and give a short overview of newer applications. PET sets the gold standard in the evaluation of an indeterminate solitary pulmonary nodule or mass, where PET has proven to be significantly more accurate than computed tomography (CT) in the distinction between benign and malignant lesions. In the evaluation of metastatic spread to locoregional lymph nodes, PET is significantly more accurate than CT, so that invasive surgical staging may be omitted in many patients with negative mediastinal PET images. In patients with positive mediastinal PET images, invasive surgical staging remains mandatory because of the possibility of false-positive findings due to inflammatory nodes or granulomatous disorders. In the search for metastatic spread, PET is a useful adjunct to conventional imaging. This may be due to the finding of unexpected metastatic lesions or due to exclusion of malignancy in lesions that are equivocal on standard imaging. However, at this time, PET does not replace conventional imaging. Large-scale randomized studies are currently examining whether PET staging will actually improve the appearance of lung cancer outcome.     

18F-FDG PET/CT在鼻咽癌诊断及分期中的临床价值

背景与目的:PET/CT能够通过准确显示肿瘤形态、大小及相邻关系从而对鼻咽癌(NPC)进行诊断及分期研究.本研究结合PET/CT、MRI结果及部分颈部小淋巴结病理结果,探讨18SF-FDG PET/CT在鼻咽癌TNM分期中的价值.方法:从2005年9月至2007年3月.选取行PET/CT和MRI检查的鼻咽癌患者68例.PET数据采用2D采集模式,CT扫描电压140 kV,采用自动毫安量跟踪扫描加血管增强的扫描方案,18F-FDG按3.7～5.5 MBq/kg剂量静脉注射.MRI检查采用T1W和T2W成像及T1W增强扫描成像.并对其中10例患者颈部小淋巴结切除和穿刺组织病理检查,进行图像与病理对照.结果:68例鼻咽癌患者所有鼻咽区域的病灶PET/CT均可以清晰显示,MRI和PET/CT显示病灶一致:对于直径≤1 cm的138枚PET/CT示阳性小淋巴结,MRI仅有约28%可作不肯定提示.10例鼻咽癌患者颈部16枚PET/CT显示阳性小淋巴结与病理结果相符14枚,符合率达87.5%.对于颈部肿大淋巴结PET/CT.和MRI均能显示,对部分放疗过程PET/CT示增殖活性明显受抑制的肿大淋巴结,MRI和PET/CT增强扫描可见强化.对于其中8例Ⅳb期鼻咽癌患者肺、骨、肝脏等转移灶,PET/CT全身扫描可清晰显示病灶,而MRI具有较多限制.由于18F-FDG PET/CT检查使其中24例的分期进行调整.结论:18F-FDG-PET/CT扫描采用自动毫安量跟踪扫描加血管增强的扫描方案,充分利用PET/CT信息进行鼻咽癌的临床分期,其结果较MRI全面、可靠.     

Pitfalls in lymph node staging with positron emission tomography in non-small cell lung cancer patients

BACKGROUND: The evidence of clinical value of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in lymph node (LN) staging in non-small cell lung cancer (NSCLC) has been shown in numerous papers. However, few studies have assessed its limitations. The aim of the present study is to clarify clinico-pathologic factors responsible for false PET results. METHODS: From July 2000 through December 2001, 71 NSCLC patients underwent both FDG PET and surgical intervention at the National Cancer Center Hospital East, Chiba. Clinical records, computed tomographic (CT) scan findings, PET findings, and histologic findings were retrospectively reviewed. RESULTS: Sensitivity, specificity, accuracy in nodal staging for CT were 29, 83, and 65% and for PET were 39, 79, and 66%, respectively. There were 10 (14%) false-positive PET scans and 14 (20%) false-negative PET scans. The causative factors for false-positive PET scan were: (1) inflammatory conditions in seven patients; (2) PET mis-localization of an interlobar LN as a mediastinal LN in one patient; (3) inability to distinguish the endobronchial polypoid growth of a primary tumor from a lobar LN in one patient; (4) unknown in one patient. All false-positive LNs due to inflammatory conditions showed reactive lymphoid hyperplasia histologically. The causative factors for false-negative PET scan were: (1) limitation of spatial resolution of the PET scanner in 12 patients (maximum tumor focus dimensions in false-negative LNs ranging from 1 to 7.5 mm, with an average of 3.4 mm); (2) PET mis-localization of a mediastinal LN as a hilar LN in one patient; (3) weak FDG uptake by microscopic tumor foci due to necrosis with massive bleeding in a metastatic LN in one patient. CONCLUSIONS: Inflammatory conditions were most responsible for false-positive PET scans, and spatial resolution limitation of FDG PET was the causative factor of false-negative PET scans. Recognizing these factors in advance would be clinically helpful in accurate nodal staging with FDG PET.     

Locoregional lymph node involvement on 18F-FDG PET/CT in breast cancer patients scheduled for neoadjuvant chemotherapy

The optimal method for locoregional staging in patients treated with neoadjuvant chemotherapy (NAC), usually ultrasound (US) and pre- or post-chemotherapy sentinel lymph node biopsy (SLNB), remains subject of debate. The aim of this study was to assess the value of 18F-FDG PET/CT for detecting locoregional lymph node metastases in primary breast cancer patients scheduled for NAC. 311 breast cancer patients, scheduled for NAC, underwent PET/CT of the thorax in prone position with hanging breasts. A panel of four experienced reviewers examined PET/CT images, blinded for other diagnostic procedures. FDG uptake in locoregional nodes was determined qualitatively using a 4-point scale (0 = negative, 1 = questionable, 2 = moderately intense, and 3 = very intense). Results were compared with pathology obtained by US-guided fine needle aspiration or SLNB prior to NAC. All FDG-avid extra-axillary nodes were considered metastatic, based on the previously reported high positive predictive value of the technique. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG-avid nodes for the detection of axillary metastases (score 2 or 3) were 82, 92, 98, 53, and 84 %, respectively. Of 28 patients with questionable axillary FDG uptake (score 1), 23 (82 %) were node-positive. Occult lymph node metastases in the internal mammary chain and periclavicular area were detected in 26 (8 %) and 32 (10 %) patients, respectively, resulting in changed regional radiotherapy planning in 50 (16 %) patients. In breast cancer patients scheduled for NAC, PET/CT renders pre-chemotherapy SLNB unnecessary in case of an FDG-avid axillary node, enables axillary response monitoring during or after NAC, and leads to changes in radiotherapy for a substantial number of patients because of detection of occult N3-disease. Based on these results, we recommend a PET/CT as a standard staging procedure in breast cancer patients scheduled for NAC.     

The additional value of integrated PET/CT over PET in initial lymph node staging of esophageal cancer

The purpose of the present study was to assess the contribution of simultaneous functional/anatomical imaging using integrated 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT), compared with PET alone for the evaluation of initial lymph node staging in esophageal cancer. We studied 167 consecutive patients with thoracic esophageal squamous cell carcinoma (SCC) who had radical esophagectomy performed between January 1999 and April 2007. For individual nodal group evaluation, PET/CT showed 46.0% sensitivity (p<0.05 vs. PET), 99.4% specificity, 95.1% accuracy (p<0.05 vs. PET), 87.0% positive and 95.5% negative predictive values. PET showed 32.9% sensitivity, 98.9% specificity, 93.1% accuracy, 74.7% positive predictive value and 93.9% negative predictive value. Thus, the sensitivity and accuracy of PET/CT were significantly higher than those of PET. Comparisons between CT, PET and PET/CT in detecting lymph node metastasis by each region showed that PET/CT had a higher sensitivity in lower thoracic regions than PET and CT (p<0.05 vs. CT and PET). Lymph node staging (N0 vs. N1) was not significantly different, but staging per lymph nodal group was significantly better with PET/CT. Integrated PET/CT imaging with co-registration of anatomic and functional imaging data is useful in the initial lymph node staging of patients with operable esophageal cancer compared with PET alone.     

PET/CT与MRI在鼻咽癌淋巴结转移诊断和N分期中的比较研究

目的 比较PET／CT与MRI在鼻咽癌淋巴结转移诊断和N分期中的作用。方法116例鼻咽癌患者于治疗前行PET／CT和MRI检查。依据随访结果比较PET／CT和MRI在淋巴结转移诊断和N分期中的作用。结果116例患者的614个淋巴结的随访结果显示,阳性340个,阴性274个。PET／CT诊断转移淋巴结的敏感性、特异性及准确性分别为93．2％、98．2％和95．4％,而MRI分别为88．8％、91．2％和89．9％,两者各指标比较,差异有统计学意义（P〈0．05）。按1992年福州分期,109例（94．0％）的PET／CT分期正确,103例（88．8％）的MRI分期正确;按UICC分期,108例（93．1％）的PET／CT分期正确,100例（86．2％）的MRI分期正确。结论PET／CT判断鼻咽癌淋巴结转移和N分期较MRI准确,但对炎性增生、大面积坏死淋巴结,或直径小于PET空间分辨率的转移淋巴结应警惕其假阳性和假阴性判断。     

18F-FDG PET/CT显像在食管癌分期中的应用

目的:探讨18F-FDG PET/CT显像在食管癌分期中的应用价值.方法:对23例病理学确诊的食管癌患者,术前1周行全身PET/CT显像,根据病理结果评价PET/CT显像在食管癌分期中的应用价值.结果:19例患者进行了食管癌切除和淋巴结清除术,PET/CT显像发现50处病灶,与病理结果相比较,假阳性5处,假阴性3处,PET/CT诊断灵敏性为94%,特异性为76%;另4例患者因PET/CT发现多发转移而改变了治疗方案.结论:应用18F-FDG PET/CT进行食管癌检查能显著提高分期的敏感性和准确性,具有较好的临床应用前景.     

^18F-FDG PET/CT显像在食管癌分期中的应用

目的：探讨^18F-FDG PET/CT显像在食管癌分期中的应用价值。方法：对23例病理学确诊的食管癌患者,术前1周行全身PET/CT显像,根据病理结果评价PET/CT显像在食管癌分期中的应用价值。结果：19例患者进行了食管癌切除和淋巴结清除术,PET/CT显像发现50处病灶,与病理结果相比较,假阳性5处,假阴性3处,PET/CT诊断灵敏性为94%,特异性为76%;另4例患者因PET/CT发现多发转移而改变了治疗方案。结论：应用^18F-FDG PET/CT进行食管癌检查能显著提高分期的敏感性和准确性,具有较好的临床应用前景。     

^18F—FDGPET／CT诊断非小细胞肺癌纵隔淋巴结转移的方法和价值

目的本研究通过目测法、测量法以及模式识别方法对非小细胞肺癌（non—small cell lungcancer,NSCLC）患者纵隔淋巴结的PET／CT图像进行诊断分析,并与病理结果比较,探索各种诊断方法的诊断效能,为临床医生提供有关NSCLC区域淋巴结转移的准确信息。方法选择术前行全身PET／CT检查且经手术根治切除的NSCLC患者28例作为研究对象,由3名有经验的医生分别应用目测法及测量法对淋巴结的CT、PET以及PET／CT图像进行分析,并与病理结果进行对比;同时通过对淋巴结的PET和CT图像的提取,应用工程学一种新的模式识别方法进行分类诊断。结果CT、PET、PET／CT测量法对NSCLC淋巴结诊断的灵敏性分别为53．6％、80．4％、82．1％;特异度分别为92．2％、83．3％、90．6％;阳性预测值分别为68．2％、60．0％、73．0％;阴性预测值分别为86．5％、93．2％、94．2％;诊断符合率分别为83．1％、82．6％、88．6％;CT、PET、PET／CT目测法对NSCLC淋巴结诊断的灵敏性分别为53．6％、71．4％、69．6％;特异度分别为85．0％、82．2％、88．9％;阳性预测值分别为52．6％、55．6％、66．7％;阴性预测值分别为85．5％、90．2％、90．4％;诊断符合率分别为77．5％、79．7％、84．3％。模式识别法计算得出PET的灵敏度为88％,特异度为76％;CT的灵敏度为84％,特异度为66％。结论PET／CT测量法以及目测法对NSCLC淋巴结转移的诊断明显优于单独的CT或单独的PET;PET／CT测量法对NSCLC淋巴结转移的诊断明显优于目测法。初步探索了通过构建多分辨率直方图及支持向量机（SVM）分类判别的工程学方法对淋巴结图像进行分析,为今后多学科联合以及探索更准确的无创检查手段奠定了基础。     

CT横断面上肺癌淋巴引流区域的界定及勾画

背景与目的：肺癌常有肺门和纵隔淋巴结转移，在三维适形放疗（3 dimensional conformal radiation therapy，3-DCRT）中，不同医师基于CT图像勾画的淋巴引流区域有明显差别。本研究在CT横断面上定义肺门和纵隔淋巴引流区界线，以减少靶区勾画的差异。方法：收集2004年11月-2005年11月中山大学附属肿瘤医院非小细胞肺癌（non-small-cell lung cancer，NSCLC）患者治疗前CT、PET／CT，选择一中等身材女性胸部CT增强扫描图像（Dicom格式）作为模板，将肺门和纵隔阳性淋巴结标注在模板CT相应位置，根据淋巴引流区域的定义和转移淋巴结的实际情况用Adobe photoshop CS软件标出界线，并在Exomio 2．0系统上进行各淋巴结区的勾画。结果：收集40位NSCLC患者胸部CT增强扫描资料（其中10位行PET／CT），在CT模板上标注了278枚淋巴结。确定了1．2R、1-2L、3A、3P、4R、4L、5、6、7、8、10-11R、10-11L组淋巴结区域的界线，在模板CT上根据标注淋巴结勾画出以上淋巴结区域。结论：在CT横断面上对肺门和纵隔淋巴区域界线的准确定义有助于肺癌转移淋巴结的分组和分期诊断，有助于提高淋巴引流区勾画的一致性和可重复性。     

18F-FDG PET-CT在非小细胞肺癌术前区域淋巴结分期中的价值

目的 探讨18F-FDG PET-CT在非小细胞肺癌(NSCLC)患者术前区域淋巴结(N)分期方面的价值,以及CT密度和双时相扫描在淋巴结性质判定方面的作用.方法 43例手术病理证实的NSCLC患者均于术前行18F-FDG PET-CT扫描,对常规扫描图像采用PET法(单纯根据18F-FDG摄取水平判断淋巴结性质)和PET+CT密度法(结合CT密度和摄取水平判断淋巴结性质)分析.摄取水平通过目测法和半定量分析法结合判定.双时相扫描的储留指数(RI)>10%为摄取升高.以病理检查作为金标准对所得结果进行分析.结果 以区域淋巴结组为单位,PET法的诊断敏感度、特异度、准确度、阳性预测值和阴性预测值分别为88.0%、88.4%、88.3%、59.5%和97.4%,PET+CT密度法的相应值分别为84.0%、94.6%、92.9%、75.0%和96.8%,其中2种方法的特异度和准确度之间差异有统计学意义(P<0.05).28组淋巴结行双时相扫描,良恶性组摄取变化值(△SUVmax)之间和砒之间差异无统计学意义(P>0.05);在23组延迟相摄取升高的淋巴结中,11组为转移;在5组无摄取升高的淋巴结中,1组为转移.结论 18F-FDG PET-CT在肺癌患者术前N分期方面有较高的诊断价值,结合淋巴结CT密度和18F-FDG摄取水平可进一步提高诊断的特异度和准确度.对于常规相摄取增高的淋巴结,延迟相摄取升高对判断淋巴结性质的价值有限,但无摄取升高则更支持良性诊断.     

Additional value of MR/PET fusion compared with PET/CT in the detection of lymph node metastases in cervical cancer patients

We evaluated the additional diagnostic value of magnetic resonance/positron emission tomography (MR/PET) fusion in the detection of metastatic lymph nodes in cervical cancer patients.Seventy nine patients with FIGO stage IB-IVA cervical cancer who had undergone both magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) before lymphadenectomy were included in this study. Image analysis was first performed with PET/CT images only. A second analysis was then performed with MR/PET fused images that focused on the additional information obtained from the MR images. Lymphadenectomy involved removing all visible lymph nodes in the surgical field. To enable nodal group-specific comparisons, para-aortic and pelvic lymph nodes were divided into seven nodal groups: para-aortic, both common iliac, both external iliac and both internal iliac/obturator areas. Histopathological evaluation of lymph nodes has been the diagnostic standard. The value of the additional information from the MR images was evaluated by means of receiver operating characteristic (ROC) analysis.Fused MR/PET rendered readers to detect six more metastatic lymph node groups. The sensitivity and specificity of PET/CT and fused MR/PET were 44.1%, 93.9% and 54.2%, 92.7% respectively. The ROC analysis demonstrated a higher diagnostic performance of fused MR/PET compared to PET/CT alone for detecting lymph node metastases (p = 0.0259).The findings of this study demonstrate the additional diagnostic value of fused MR/PET images compared with PET/CT in the detection of metastatic lymph nodes in patients with uterine cervical cancer.     

Metastatic incidence of (PET)CT positive lung hilar and retroperitoneal lymph nodes in esophageal cancer patients

BackgroundExtra-regional lymph node metastases strongly determine treatment options in patients with esophageal cancer. Staging modalities such as (FDG-PET) CT scanning frequently show activity in retroperitoneal and lung hilar lymph nodes. This study evaluated the incidence of histologically confirmed metastases, treatment approach and recurrence patterns in patients with (FDG-PET) CT positivity in these regions.MethodsAll patients with (FDG-PET-) CT positive hilar and/or retroperitoneal lymph nodes at primary staging or restaging discussed at a multidisciplinary tumor board meeting for staging of esophageal cancer between January 2012–December 2017 were included. Biopsies and follow-up were evaluated to determine the presence of metastases and progression rates.ResultsFrom 2012 to 2017, 65 of 857 patients (7.6%) were selected with positive retroperitoneal and/or hilar lymph nodes. A total of 47/65 (72.3%) patients had positive retroperitoneal lymph nodes, which contained metastases in 19 (29.2%). When no biopsy was performed and curative treatment was given (n = 14), 9 patients had progression or locoregional and distant recurrence. Positive hilar lymph nodes were identified in 21 (32.3%) patients; 4 were biopsied and none contained metastases. In these patients no recurrence of disease was seen during follow-up.ConclusionsThe majority of biopsied (PET)CT-positive retroperitoneal lymph nodes at staging contained metastases, while biopsied (PET)CT-positive hilar nodes did not. Histological evaluation of (PET)CT -positive retroperitoneal lymph nodes at staging imaging is recommended, while based on this small series, (PET)CT-positive hilar lymph nodes most likely represent reactive lymphadenopathy.     

Characteristics of advantages of positron emission tomography over computed tomography for N-staging in lung cancer patients

OBJECTIVE: We analyzed the characteristics of advantages of positron emission tomography (PET) over computed tomography (CT) for N-staging in lung cancer patients. METHODS: Preoperative PET and CT scans were performed for 2057 lymph node stations in 205 patients with peripheral-type lung cancer. The advantages of PET over CT for N-staging were analyzed among lymph node locations and histological subtypes. RESULTS: The pathological N-stages were N0 in 143 patients, N1 in 31, N2 in 24 and N3 in 7. PET was able to diagnose N0, N2 and N3 diseases more accurately than CT (P=0.03, 0.01 and 0.02, respectively), but there was no significant difference between the two modalities for N1 disease. In the upper mediastinal lymph node stations, both false-negative and false-positive were significantly less frequent with PET than with CT (P=0.001). In the lower mediastinal and supra clavicle lymph nodes, PET showed a lower frequency of false-negative than CT (P=0.04 and 0.003, respectively), but there was no significant difference in the frequency of false-positive between the two modalities. Among histological types, PET could stage adenocarcinoma with less frequent false-negative and squamous cell carcinoma with less frequent false-positive than CT (P=0.02 and 0.005, respectively). CONCLUSION: For N-staging, PET was superior to CT for the following: (1) more accurate for N0, N2 and N3 diseases but not for N1; (2) lower frequency of false-positive in the upper mediastinal nodes; and (3) lower frequencies of false-negative in adenocarcinoma and false-positive in squamous cell carcinoma. Recognizing these advantages of PET could make the N-staging of lung cancer more accurate.     

PET在肺癌临床中的应用

目的探讨18氟脱氧葡萄糖正电子发射计算机断层扫描(18F-FDG PET)对肺癌诊断、分期、疗效评价及随访等方面的临床意义.方法对56例肺癌患者18F-FDG PET显像的临床资料进行回顾性分析,所有病灶的标准摄取值(SV)均以2.5界定为肺癌病灶.结果PET用于肺癌临床:①敏感性92.8%;②特异性89.3%;③对肺癌诊断的准确率91.O%;④假阳性率5.4%,假阴性率3.6%;⑤对肺癌纵隔淋巴结转移诊断的准确性稍高于CT,分别为85.0%和70.0%;⑥PET在评价传统的三维定位适形放射治疗及局部病灶消融疗法的疗效以及随访等方面发挥重要作用.结论18F-FDG PET可用于肺癌的诊断、分期、评价疗效及随访.     

[18F]-FDG–PET in clinical stage I/II non-seminomatous germ cell tumours: results of the German multicentre trial

PurposeThe aim of this study was to determine the predictive values of 2-[fluorine-18]fluoro-2-deoxy-D-glucose–positron emission tomography (FDG–PET) in primary staging in patients with newly diagnosed non-seminomatous germ cell tumour (NSGCT) clinical stage I/II.Patients and methodsThe hypothesis was that FDG–PET would improve the negative predictive value (NPV) from 70% to 90%, thus requiring a total of 169 patients. All scans underwent visual analysis by a reference team of nuclear medicine physicians. Results were validated by histology following retroperitoneal lymph node dissection.ResultsOnly 72 of the planned 169 patients were included, due to poor accrual. The prevalence of nodal involvement was 26%. Correct nodal staging by FDG–PET was achieved in 83% compared with correct computed tomography (CT) staging in 71%. CT had a sensitivity and specificity of 41% and 95%, respectively. Positive predictive value (PPV) and NPV were 87% and 67%, respectively. FDG–PET had a sensitivity and specificity of 66% and 98%, respectively. PPV was 95%. The primary end point was not reached, with an NPV of 78%.ConclusionFDG–PET as a primary staging tool for NSGCT yielded only slightly better results than CT. Both methods had a high specificity while false-negative findings were more frequent with CT. FDG–PET is mostly useful as a diagnostic tool in case of questionable CT scan.     

PET/CT双定量分析在良恶性颈部淋巴结鉴别诊断中的价值

  目的  探讨18F-FDG PET/CT SUVmax及CT短径双定量分析在良恶性颈部淋巴结鉴别诊断中的价值。  方法  回顾性分析本院2005年4月~2011年9月期间以颈部淋巴结肿大为首发症状行18F-FDG PET/CT检查的82例患者的显像情况。以病理诊断为金标准, 对CT、PET、PET/CT图像结果进行定量分析, 绘制SUVmax值及CT短径的ROC曲线, 找到最佳诊断界点, 分别计算单纯CT、单纯PET以及PET/CT双定量分析的敏感度、特异度、阳性预测值、阴性预测值、准确度等指标, 并对其结果进行统计学分析。  结果  当CT短径≥0.65cm且SUVmax≥1.95, 18F-FDG PET/CT显像诊断良恶性颈部淋巴结的灵敏度、特异度、阳性预测值、阴性预测值、准确度分别为79.30%、94.52%、95.15%、77.09%、85.76%, 其准确度高于单纯PET或单纯CT。  结论  18F-FDG PET/CT双定量分析对良恶性颈部淋巴结的鉴别诊断具有较高的临床价值, 其准确性优于单纯PET或单纯CT: 当CT短径≥0.65cm且SUV-max≥1.95.提示颈部淋巴结恶性可能性大。