Assessment of cervical lymph node metastases using FDG-PET in patients with head and neck cancer

OBJECTIVE: To evaluate the diagnostic accuracy of fluorodeoxyglucose positron emission tomography (FDG-PET) relative to computed tomography (CT) for detecting metastatic cervical lymph nodes in patients with squamous cell carcinoma of the head and neck (HNSCC), and to ascertain the factors that affect this accuracy. METHODS: A total of 1076 lymph nodes obtained from 35 neck dissections in 26 HNSCC patients who preoperatively underwent both FDG-PET and CT were retrospectively analyzed. For pathological metastatic lymph nodes, the lymph node size (short-axis diameter), the ratio of intranodal tumor deposits, and the size of intranodal tumor deposits (maximum diameter of metastatic foci in each lymph node) were histologically recorded. RESULTS: Forty-six lymph nodes from 23 neck sides were pathologically diagnosed metastases. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET evaluated individually per neck side were 74%, 92%, 80%, 94%, and 65%, respectively, whereas those of CT were 78%, 58%, 71%, 78%, and 58%, respectively. FDG-PET detected 100% of metastatic lymph nodes > or =10 mm, intranodal tumor deposits > or =9 mm, and intranodal tumor deposits with a ratio >75%, whereas no nodes or tumor deposits smaller than 5 mm were detected. The spatial resolution limitations of FDG-PET were responsible for 16 of 20 (80%) false-negative PET results in lymph nodes. CONCLUSIONS: FDG-PET is a useful tool for preoperative evaluation of the neck because it accurately detects metastatic lymph nodes > or =10 mm and has fewer false-positive cases than CT. The high specificity of FDG-PET for lymph node metastases may play an important role in avoiding unnecessary neck dissection.     

Influence of different criteria for abnormal lymph node size on reliability of computed tomography in patients with non-seminomatous testicular tumor

The reliability of computed tomography (CT) using different criteria for abnormal size of retroperitoneal lymph nodes (5, 10, 15 mm in largest diameter) was evaluated prospectively in 90 consecutive patients with a non-seminomatous testicular tumor and lymph nodes less than 20 mm at CT. Correlation was made with histologic findings following retroperitoneal lymphadenectomy. Histologic examination revealed metastases in 38 patients (42%). Using a strict criterion of 15 mm for abnormal node size, sensitivity was 37%, specificity 98%, positive predictive value 93% and negative predictive value 68%. A relaxed criterion of 5 mm led to a sensitivity of 71%, specificity 67%, positive predictive value 61% and negative predictive value 76%. Overall accuracy was approximately 70% with the 5, 10 and 15 mm criteria for abnormal size. The inability of a normal scan to exclude metastases was the main limitation of CT.     

多层螺旋CT和正电子发射计算机体层成像-CT评价乳腺癌腋窝淋巴结状态的对照研究

目的探讨多层螺旋CT（MSCT）、正电子发射计算机体层成像-CT（PET-CT）评价乳腺癌腋窝淋巴结转移的价值。方法手术病理证实的乳腺癌患者40例均行MSCT增强扫描，其中的13例行^18F脱氧葡萄糖（^18F-FDG）PET—CT检查。3名医师分别采用5分评价法对CT图像中淋巴结进行综合评分，≥3分时该淋巴结记录为阳性（淋巴结有转移），〈3分时记录为阴性。采用目测法和半定量分析法相结合分析PET—CT图像所显示的淋巴结，分别作阴、阳性记数。将PET-CT、增强MSCT对腋窝淋巴结的检出结果与手术病理结果进行对照。用精确概率法对结果进行统计学分析。结果40例患者行MSCT检查共检出腋窝淋巴结158枚，其中CT阳性计数91枚，阴性计数67枚；术后病理阳性99枚，阴性59枚。13例行PET-CT检查者共检出腋窝淋巴57枚，PET-CT显像阳性39枚，阴性18枚；术后病理阳性39枚，阴性18枚。CT对腋窝淋巴结转移定性的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为88．89％、94．91％、91．14％、96．70％和83．58％；PET-CT分别为97．44％、94．44％、96．49％、97．44％和94．44％。CT与PET-CT对腋窝淋巴结转移定性的敏感性、特异性、准确性和阳性预测值差异无统计学意义（P〉0．05）；但PET-CT的阴性预测值高于MSCT，二者之间差异有统计学意义（P〈0．05）。结论CT、PET-CT都能准确评价乳腺癌腋窝淋巴结的状态，但PET-CT检测腋窝淋巴结的阴性预测值高于MSCT，PET-CT能在术前更准确评价乳腺癌患者腋窝淋巴结状态。     

Computed tomography and ultrasonography of metastatic cervical lymph nodes in oral squamous cell carcinoma

OBJECTIVES: To define criteria for CT and US in differentiating cervical lymph node metastases in oral squamous cell carcinoma (SCC). MATERIALS AND METHODS: CT and/or US of 230 metastatic lymph nodes and 228 benign lymph nodes in 147 patients with oral SCC were retrospectively evaluated. The CT and US findings of each lymph node were compared with the histopathological findings. A metastasis was defined on CT as a lymph node with rim or heterogeneous enhancement, or measuring 10 mm or more in the short axis, regardless of enhancement pattern, and on US as having definite internal echoes, regardless of size, or without definite internal or hilar echoes, but measuring 10 mm or more in the short axis. A lymph node with hilar echoes or a ratio of the long to short axis (L/S ratio) of 3.5 or more was considered benign. A lymph node failing to comform to any of these categories was termed questionable. RESULTS: The positive predictive value (PPV) for CT was 90.8% and the negative predictive value (NPV) was 70.4%. However, 65.7% of all lymph nodes could not be classified as either metastastic or benign. PPV for US was 96.5% and NPV was 88.1%. 25.5% of all lymph nodes could not be classified as either metastatic or benign. CONCLUSIONS: Despite limitations in detecting metastases, by including a third category 'questionable' our criteria appear clinically more useful than other current methods based on two groups only.     

多层螺旋CT对胰腺癌转移淋巴结的诊断能力初步分析

目的:分析多层螺旋CT对胰腺癌转移淋巴结的诊断能力。方法:自2005年11月～2007年3月对87例临床疑诊为胰腺肿瘤的患者行多层螺旋CT薄层扫描,根据三维重建影像学结果确定腹部淋巴结肿大情况;17例行胰腺肿瘤根治手术,其中13例确诊为胰腺腺癌;切除标本由病理科医师确定淋巴结位置及是否转移,将影像学数据与病理结果对照分析。结果:按照外形特征及淋巴结位置,CT图像中共有41枚淋巴结可与病理结果对应,其中16枚(39.0%)转移阳性,短轴直径与非转移组淋巴结比较无统计意义(P=0.27)。分别以淋巴结短轴直径大于3mm、10mm及淋巴结长短轴直径比小于2为淋巴结转移阳性诊断标准,敏感度分别为93.8%、18.8%及50%,特异度分别为40%、88%及72%,阳性预测值分别为38.5%、50%及53.3%,阴性预测值分别为50%、62.9%及69.2%,准确度分别为39%、61%及63.4%。结论:使用多层螺旋CT以适当标准判断胰腺癌淋巴结有无转移,可以获得较高的敏感度或特异度,为选择恰当的治疗方案提供依据。     

Usefulness of PET with 11C-methionine for the detection of hilar and mediastinal lymph node metastasis in lung cancer.

We retrospectively evaluated the usefulness of PET with 11C-methionine (methionine PET) for the diagnosis of lymph node metastases in patients with lung cancer. METHODS: Methionine PET and CT were performed before surgical intervention in 41 patients with primary lung cancer. We evaluated individual lymph nodes by methionine PET along with corresponding CT images. The 11C-methionine accumulation of lymph nodes was assessed semiquantitatively by analysis of the tumor-to-muscle ratio (TMR) and was compared with CT and histological diagnoses. RESULTS: A total of 126 lymph nodes, 36 of which were histologically diagnosed as metastatic, were assessed by CT and methionine PET. The TMR in metastatic lymph nodes (n = 36) was 5.15+/-1.69, whereas that of nonmetastatic lymph nodes (n = 90) was 2.91+/-0.76; this difference was significant (P < 0.0001). The most adequate TMR cutoff value for diagnosis of metastasis based on the results of receiver operating characteristic curve analysis was 4.1. The positive and negative predictive values, sensitivity, specificity, and accuracy of methionine PET were 79.5%, 94.3%, 86.1%, 91.1%, and 89.7%, respectively, and were superior to those of CT (57.6%, P = 0.04; 81.7%, P = 0.008; 52.8%, P = 0.002; 84.4%, NS; and 75.4%, P = 0.002, respectively). All positive nodes that were shown to be true-positive by CT, and 12 of 17 false-negatives on CT were correctly diagnosed by PET. Ten of 14 lymph nodes that were false-positive on CT were also correctly diagnosed by PET. CONCLUSION: Methionine PET appears to be superior to CT for the diagnosis of lymph node metastasis in lung cancer patients. The high negative predictive value of methionine PET suggests that cases in which lymph nodes are enlarged on CT with negative PET analysis may be diagnosed as negative for metastasis.     

WB-DWI在恶性肿瘤淋巴结转移中的应用

目的:探讨磁共振全身弥散加权成像(whole body diffusion-weighted imaging,WB-DWI)在恶性肿瘤淋巴结转移瘤中的应用价值。方法:对110例疑似恶性肿瘤淋巴结转移患者行WB-DWI检查,并于扫描后1周内对可疑骨转移部位及原发恶性肿瘤部位行常规MRI/CT检查。根据MRI/CT及临床综合诊断结果,将所有患者分为淋巴结转移组及非淋巴结转移组,对资料进行统计学分析,比较单独应用WB-DWI、MRI/CT及二者联合应用(WB-DWI+MRI/CT)在恶性肿瘤淋巴结转移中的诊断价值。分别测定淋巴结转移组及非淋巴结转移组的ADC值,比较其在良恶性病变鉴别诊断中的价值。结果:①将淋巴结按长径大小分为<2cm,2～3cm,>3cm,WB-DWI、MRI/CT及WB-DWI+MRI/CT对长径<2cm淋巴结转移的检出差异具有统计学意义。进一步两两比较,单独应用MRI/CT与WB-DWI+MRI/CT的差异具有统计学意义(χ2=6.519,P=0.011)。②ROC分析结果显示,WB-DWI+MRI/CT诊断恶性肿瘤淋巴结转移的特异度、诊断准确性、阳性预测值及阴性预测值诊断最高。③淋巴结转移组ADC值明显低于良性淋巴结病变组,在良恶性淋巴结转移鉴别诊断中具有一定作用。结论:WB-DWI是常规MRI、CT的有益补充,与MRI/CT的联合应用可以提高恶性肿瘤淋巴结转移的诊断率,结合ADC值测定,在恶性肿瘤淋巴结转移诊断和鉴别方面具有一定价值。     

Additional value of PET/CT over PET in assessment of locoregional lymph nodes in thoracic esophageal squamous cell cancer.

The aim of this study was to compare the value of reviewing combined 18F-FDG PET/CT images with that of reviewing side-by-side PET and CT images in the diagnosis of locoregional lymph node metastases in patients with esophageal squamous cell cancer. METHODS: From November 2003 to December 2005, 45 patients with thoracic esophageal squamous cell cancer underwent 18F-FDG PET/CT before surgery. The results of reviewing combined PET/CT images and side-by-side PET and CT images for the diagnosis of locoregional lymph node metastases were compared prospectively in relation to pathologic findings. RESULTS: All patients underwent successful surgery, and pathologic examination confirmed nodes positive for metastasis in 32 patients and 82 of 397 excised nodal groups. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT were 93.90% (77/82 nodal groups), 92.06% (290/315), 92.44% (367/397), 75.49% (77/102), and 98.31% (290/295), respectively, whereas those of PET were 81.71% (67/82), 87.30% (275/315), 86.15% (342/397), 62.62% (67/107), and 94.83% (275/290), respectively. P values were 0.032, 0.067, 0.006, 0.063, and 0.037, respectively. The differences in sensitivity, accuracy, and negative predictive value between PET and PET/CT were statistically significant. CONCLUSION: PET/CT improves the sensitivity, accuracy, and negative predictive value of 18F-FDG imaging in the assessment of locoregional lymph nodes in thoracic esophageal squamous cell cancer and provides data of diagnostic significance.     

Detection of retroperitoneal metastases in early-stage nonseminomatous testicular cancer: analysis of different CT criteria

To determine the predictive values of using different sizes on CT as criteria for the detection of retroperitoneal lymph-node metastases in patients with early-stage (nodes 5 cm or less in diameter) primary nonseminomatous testicular cancer, we performed a retrospective analysis of 51 patients. Measurements of lymph-node transaxial diameters on CT were correlated with histologic findings at lymph-node dissection or with response to initial chemotherapy. All patients had normal serum markers (alpha-fetoprotein, human chorionic gonadotropin) after orchiectomy. The frequency of lymph-node metastases in this population was 51%. When a CT criterion of 5 mm was used, the negative predictive value was 79%; the positive predictive value, 62%; the specificity, 44%; and the sensitivity, 88%. With a criterion of 15 mm, the negative predictive value was 63%; the positive predictive value, 71%; the specificity, 76%; and the sensitivity, 58%. Metastases in retroperitoneal lymph nodes that appeared within normal limits (i.e., had normal transaxial diameters) on CT were the limiting factor in the ability of CT to exclude the presence of metastases. We conclude that using smaller sizes on CT scans as the criteria for detection of lymph-node metastases cannot replace dissection of nodes in patients who have normal-sized nodes but may be helpful in identifying a subgroup of patients who are at lower risk of harboring metastases when treatment by orchiectomy alone is considered.     

PET／CT在胸段食管癌诊断与淋巴分期中的应用价值

目的：探讨^18F-脱氧葡萄糖（FDG）正电子发射型计算机断层（PET／CT）在胸段食管癌诊断与淋巴分期中的应用价值。方法：回顾性分析了经PET／CT显像的34例患者资料。患者在显像后2-3周内行手术治疗,手术时对颈、胸、上腹部三野淋巴结清扫,所有淋巴结送病理学检查。病理学证实34例患者均为鳞状细胞癌。胸上段食管癌4例,中段食管癌16例,下段食管癌14例。结果：34例患者食管肿瘤长度为1-8．3cm（4．5±1．6cm）。PET／CT均显示FIX;代谢增高,SUV最高值范围4．3-23．2（10．84±5．32）,平均SUV值3。16．7（8．92±4．09）。作为对照,分析36例PET／CT健康查体人员,发现有2例食管平滑肌瘤显示假阳性。PET／CT诊断食管癌的准确度、灵敏度、特异度、阳性预测值和阴性预测值分别为：97．1％、100％、94．4％、94．4％和100％。34例患者中有20例发生不同程度的淋巴结转移,PET／CT显示转移淋巴结高FDG代谢,SUV最高值为2．7-13．9（7．28±2．75）,SUV平均值为2．3-10．7（5．63±2．49）;其中有6例患者转移到腹腔内,6例腹腔淋巴结转移患者中有5例为下段食管癌,1例为中段食管癌。4例转移至颈部淋巴结,为中上段食管癌转移。手术清除淋巴结163枚,其中病理示转移淋巴结52枚,PET／CT显像结果与病理结果比较,有7枚小淋巴结未能显示,排除了3枚直径大于1cm的可疑转移淋巴结,有13个良性淋巴结显示假阳性,对淋巴结诊断的准确度、灵敏度、特异度、阳性预测值和阴性预测值分别为：87．7％、86．2％、88．2％、77．6％和85．2％。结论：PET／CT对食管癌原发灶的诊断有很高的价值,对淋巴结分期有较高的灵敏度与特异性。     

Computerized tomography versus lymphography in the assessment of lymph node metastasis in epithelial carcinoma of the ovary

We investigated the accuracy of both lymphangiography and CT in detecting lymph node metastases in 59 patients evaluated preoperatively and subsequently submitted to surgery with selective/systemic pelvic and paraaortic lymphadenectomy. CT accuracy was also investigated in 46 patients with a clinically suspected relapse of ovarian cancer (verified by means of clinical and/or CT follow-up in 36 patients, by laparotomy in 7, by fine-needle biopsy in 1 and by necroscopy in the last 2). In the first group (previously untreated patients) the overall results in the pelvis were, respectively, for lymphangiography and CT: 94.9% vs 89.8% accuracy, 86.6% vs 60% sensitivity, 97.7% vs 100% specificity, and 92.8% vs 100%, 95.5% vs 88% positive and negative predictive values. In the paraaortic region the results were: 89.1% vs 86.5% accuracy, 73.3% vs 66.6% sensitivity, 100% specificity for both techniques, 100% positive predictive value, and 84.6% vs 81.5% negative predictive value. In the second group (clinically suspected relapse), CT accuracy, sensitivity, and specificity were, respectively: 91.3%, 81.8%, and 100%. Our experience demonstrated a high incidence of lymph node metastases in ovarian cancer, both in pelvic (15/49; 25.5%) and especially in aortic (15/37; 40.5%) locations in untreated patients, and an even higher incidence in relapses (22/42; 52.5%). The high specificity and positive predictive value of CT depended on the fact that there were no false positives. We arbitrarily considered as metastatic a lymph node with phi greater than 2 cm, and this threshold seemed to be of clinical value since it made a good predictor of metastases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of dynamic helical CT and dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma

OBJECTIVE: This study compares dynamic helical CT with dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma. SUBJECTS AND METHODS: Women with biopsy-proven cervical carcinoma prospectively underwent dynamic helical CT and MR imaging before surgery. A metastatic node on CT and MR imaging was defined as a rounded soft-tissue structure greater than 10 mm in maximal axial diameter or a node with central necrosis. Imaging results were compared with pathology, and receiver operating characteristic curves for size and shape were plotted on a hemipelvis basis. Nodal density and signal intensity on CT and MR images, respectively, were reviewed for differences between benign and malignant disease. RESULTS: A total of 949 lymph nodes were found at pathology in 76 hemipelves in 43 women, of which 69 lymph nodes (7%) in 17 hemipelves (22%) were metastatic. Sensitivity, specificity, positive and negative predictive values, and accuracy of helical CT and MR imaging in the diagnosis of lymph node metastasis on a hemipelvis basis was 64.7%, 96.6%, 84.6%, 90.5%, and 89.5% and 70.6%, 89.8%, 66. 7%, 91.4%, and 85.5%, respectively. Receiver operating characteristic curves for helical CT and MR imaging gave cutoff values of 9 and 12 mm in maximal axial diameter, respectively, in the prediction of metastasis. Central necrosis had a positive predictive value of 100% in the diagnosis of metastasis. Signal intensity on MR imaging and density-enhancement pattern on CT in patients with metastatic nodes did not differ from those in patients with negative nodes. CONCLUSION: Helical CT and MR imaging show similar accuracy in the evaluation of pelvic lymph nodes in patients with cervical carcinoma. Central necrosis is useful in the diagnosis of metastasis in pelvic lymph nodes in cervical cancer.     

基于CT影像组学鉴别非小细胞肺癌纵隔转移性淋巴结的模型研究

目的建立不同CT扫描时相图像鉴别非小细胞肺癌(non-small cell lung cancer,NSCLC)纵隔淋巴结的影像组学模型,并探讨不同模型的诊断效能。方法回顾性分析86例NSCLC患者的术前CT图像,所有患者均行平扫期、动脉期和静脉期CT扫描。选取231枚纵隔淋巴结为研究对象,将2015年1月—2017年6月入组的163枚淋巴结作为训练组,2017年7月—2018年6月入组的68枚淋巴结作为验证组。分别在三时相图像上勾画感兴趣区域(regions of interest,ROI),每个ROI提取841个影像特征,使用LASSO算法筛选特征,基于各时相CT影像组学特征和两不同时相CT影像组学特征的差值建立模型。比较不同模型的受试者工作特征曲线(receiver operating characteristic,ROC)下面积(AUC值)、敏感性、特异性、准确度、阳性预测值和阴性预测值的差异。结果共建立6个模型,其AUC值均>0.800。平扫期CT模型具有最优的鉴别效能,其训练组的AUC值、特异性、准确度、阳性预测值分别为0.926、0.860、0.871、0.906,验证组的AUC值、特异性、准确度、阳性预测值分别为0.925、0.769、0.882、0.870,均高于其他模型。平扫和静脉期CT图像联合动脉期CT图像之后,训练组的敏感性、阴性预测值分别从0.879、0.821和0.919、0.789提高到0.949、0.878和0.979、0.900。结论CT各时相影像组学模型均可用于辅助临床诊断淋巴结。平扫CT影像组学模型的AUC值最高,而联合动脉期CT图像可提高模型的敏感度及阴性预测值。     

Gray scale and power Doppler US in the preoperative evaluation of axillary metastases in breast cancer patients with no palpable lymph nodes

The purpose of this study is to evaluate the accuracy of gray scale and Doppler US findings in the detection of axillary metastases in breast cancer patients with no palpable lymph nodes. One-hundred and ninety-eight lymph nodes detected in 83 women were evaluated. The size and longitudinal/transverse axis ratios of each node were documented. Absence of echogenic hilum, asymmetrical cortical thickening, and presence of peripheral flow were prospectively considered signs of malignancy. Histopathologically, there were 93 malignant and 105 benign nodes. The above criteria and a low longitudinal-transverse axis ratio were statistically significant for malignancy. In lymph nodes smaller than 1 cm, only asymmetric cortical thickening and presence of peripheral flow were significant. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of US were 86.49, 93.62, 91.43, 89.8 and 90.48%, respectively. In conclusion, US is successful and reliable in the determination of axillary metastatic involvement in nonpalpable and small lymph nodes. Inclusion of axillary US in the preoperative diagnostic evaluation would be complimentary to sentinel node biopsy, and also could eliminate the need for it in patients with positive US results, after confirmation with biopsy.     

CT-pathologic correlation of axillary lymph nodes in breast carcinoma

A prospective study was performed to determine whether thoracic CT yielded useful information regarding the status of axillary lymph nodes (LNs) in patients with breast cancer. Thirty-five consecutive patients with clinically suspected stage II or III breast carcinomas were scanned preoperatively from the supraclavicular regions to the lung bases. Axillary LNs measuring greater than or equal to 1 cm were considered abnormal. The lymph nodes were classified according to their relationship to the pectoralis muscle. Extracapsular lymph node extension was diagnosed when there was irregularity and spiculation of the lymph node margin with surrounding fatty infiltration. Correlation with axillary dissection was obtained in 20 patients, giving a positive predictive value for axillary metastases of 89% with 50% sensitivity, 75% specificity, and 20% negative predictive value. CT was also able to detect the level of axillary involvement accurately when the lymph nodes were enlarged and to evaluate extracapsular LN extension. Although superior to physical examination, CT was not an accurate predictor of axillary LN involvement, primarily because of its low negative predictive value.     

Urinary bladder cancer: preoperative nodal staging with ferumoxtran-10-enhanced MR imaging

PURPOSE: To prospectively evaluate ferumoxtran-10-enhanced magnetic resonance (MR) imaging for nodal staging in patients with urinary bladder cancer. MATERIALS AND METHODS: Fifty-eight patients with proved bladder cancer were enrolled. Results of MR imaging performed before and after injection of ferumoxtran-10 were compared with histopathologic results in surgically removed lymph nodes. High-spatial-resolution three-dimensional T1-weighted magnetization-prepared rapid acquisition gradient-echo (voxel size, 1.4 x 1.4 x 1.4 mm) and T2*-weighted gradient-echo (voxel size, 0.8 x 0.8 x 3.0 mm) sequences were performed before and 24 hours after injection of ferumoxtran-10 (2.6 mg iron per kilogram of body weight). On precontrast images, lymph nodes were defined as malignant by using size and shape criteria (round node, >8 mm; oval, >10 mm axial diameter). On postcontrast images, nodes were considered benign if there was homogeneous decrease in signal intensity and malignant if decrease was absent or heterogeneous. Qualitative evaluation was performed on a node-to-node basis. Sensitivity, specificity, predictive values, and accuracy were evaluated with logistic regression analysis. RESULTS: In 58 patients, 172 nodes imaged with use of ferumoxtran-10 were matched and correlated with results of node dissection. Of these, 122 were benign and 50 were malignant. With nodal size and shape criteria, accuracy, sensitivity, specificity, and positive and negative predictive values on precontrast images were 92%, 76%, 99%, 97%, and 91%, respectively; corresponding values on postcontrast images were 95%, 96%, 95%, 89%, and 98%. In the depiction of pelvic metastases, sensitivity and negative predictive value improved significantly at postcontrast compared with those at precontrast imaging, from 76% to 96% (P < .001) and from 91% to 98% (P < .01), respectively. At postcontrast imaging, metastases (4-9 mm) were prospectively found in 10 of 12 normal-sized nodes (<10 mm); these metastases were not detected on precontrast images. Postcontrast images also showed lymph nodes that were missed at pelvic node dissection in two patients. CONCLUSION: Ferumoxtran-10-enhanced MR imaging significantly improves nodal staging in patients with bladder cancer by depicting metastases even in normal-sized lymph nodes.     

Evaluation of the "N" factor in nonsmall cell lung cancer. Correlation between computerized tomography and pathologic anatomy

PURPOSE: To evaluate the role of CT in identifying other morphological signs of metastatic lymph node involvement from non small cell bronchogenic carcinoma. This is done to improve N staging, a critical step in this disease. In fact, since diameter is the only criterion used to distinguish normal form abnormal lymph nodes, medistinal CT only has 80% diagnostic accuracy. MATERIAL AND METHODS: 137 patients with known or suspected lung cancer were examined with Helical CT during early and late arterial phases (2 min delay, 3 mm thickness, 5 mm interslice gap) to depict node characteristics. Mediastinal lymph nodes, located according to the American Thoracic Society mapping, were considered normal when they were not visible or, if visible, less than 1 cm in diameter and of homogeneous density; lymph nodes over 1 cm in diameter and homogeneous density were considered reactive. A lymph node was considered metastatic when, independent of size, the following signs were found: central hypodensity; hyperdense thin/thick rim, with nodules within; hyperdense strands or diffuse hyperdensity in perinodal adipose tissue. The tumor site was also considered. RESULTS: Seventy patients were excluded because they were inoperable. Sixty-five of the remaining 67 patients were operated on, 1 underwent mediastinoscopy and another one mediastinoscopy followed by surgery. Based on the above CT signs, 46 patients were staged as N0, 61 as N1 and 15 as N2. In 44/46 N0 patients there was agreement between anatomical and pathologic findings; 3 of the 44 patients had lymph nodes over 1 cm in diameter and with homogeneous density. Micrometastases to mediastinal lymph nodes (N2) were found at histology in 2/46 patients (CT false negatives). In the 6 N1 and the 15 N2 patients there was complete agreement between anatomical and pathologic findings; in particular, 9 N2 patients had lymph nodes less than 1 cm in diameter with signs of metastasis and 4 had lymph nodes over 1 cm in diameter with signs of metastasis and 2 had lymph nodes either over or less than 1 cm. In all N2 patients the tumor histotype and the mediastinal location were also considered relative to the lesion site. DISCUSSION: A closer correlation was found with node morphology and density than with size. Indeed, CT sensitivity, specificity and diagnostic accuracy were 97, 100 and 97%, respectively, for the former versus 52, 93 and 77% for the latter. Adenocarcinoma was the predominant histotype (70.5%) in N2 patients. Metastases to node region 4 were predominant in right upper lobe carcinomas while node region 5 was predominant in left upper lobe lesions. CONCLUSIONS: Other criteria can be associated with size to improve CT diagnostic accuracy in N staging. Technique optimization plays a major role particularly in the late, thin slice, examination phase.     

CT及18F-FDGPET/CT诊断食管癌术前淋巴结转移及N分期对比研究

目的 研究CT及18F-氟脱氧葡萄糖(FDG) PET/CT术前诊断食管癌淋巴结转移及确定N分期的价值.资料与方法 连续随机选择经食管镜或胃镜证实、拟行手术治疗、能够耐受手术的47例食管癌患者,术前1周内行CT及18F-FDG PET/CT检查,以术后病理为“金标准”,比较CT及18F-FDG PET/CT诊断食管癌淋巴结转移及N分期的敏感性、特异性、准确性、阳性预测值及阴性预测值.结果 31例存在淋巴结转移,共切除并分离淋巴结387枚(209组),其中65枚(46组)发现转移.CT诊断淋巴结转移的敏感性、特异性、准确性、阳性预测值、阴性预测值分别为53.8％、92.8％、86.3％、60.3％和90.9％;18F-FDG PET/CT分别为89.2％、93.8％、93.0％、74.4％和97.7％.PET/CT诊断淋巴结转移的敏感性、准确性及阴性预测值均显著高于CT,差异有统计学意义(P＜0.05),特异性及阳性预测值差异无统计学意义(P＞0.05).CT及18F-FDG PET/CT确定淋巴结分期的准确率分别为74.5％和91.5％,差异有统计学意义(P＜0.05).伴淋巴结转移的食管癌原发灶最大标准摄取值(SUVmax)为( 14.899±3.770),而无淋巴结转移者为(9.427±2.854).结论 18F-FDGPET/CT术前诊断食管癌淋巴结转移及确定N分期优于CT;食管癌原发灶SUVmax在一定程度上可以反映淋巴结转移情况.     

Carcinoma of the cervix: lymphangiography and computed tomography

Twenty-four patients with carcinoma of the uterine cervix examined by lymphangiography followed by computed tomography (CT) were reviewed to assess the findings and their impact on management. The lymphangiogram was of value in detecting metastases in relatively small nodes, (less than 1.5 cm maximum diameter) and in differentiating metastases from reactive hyperplasia in the larger lymph nodes which were opacified. Although as yet unable to define alterations in the internal architecture of lymph nodes. CT detected masses of lymph nodes totally replaced by neoplasm or those not visualized by lymphangiography. In addition, the local extension of the primary neoplasm and distant metastases, such as to the urinary tract, liver, and skeleton, were readily demonstrated by CT. In advanced or recurrent disease, CT provided new information on 10 of 17 patients but resulted in a change in management for only one.     

The usefulness of FDG positron emission tomography for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer: a comparative study with X-ray computed tomography

We evaluated the usefulness of fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) in the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer and then compared the findings with the results of X-ray CT by region based on the histological diagnoses. We examined 29 patients with non-small cell lung cancer. One hundred and thirty-two mediastinal lymph nodes were surgically removed and the histological diagnoses were confirmed. FDG PET images, including 146 mediastinal regions, were visually analysed and the mediastinal lymph nodes were scored as positive when the FDG uptake was higher than that in the other mediastinal structures. On the X-ray CT scans, any mediastinal lymph nodes with a diameter of 10 mm or larger were scored as positive. All three examinations were successfully performed on 71 regions. For FDG PET, we found a sensitivity of 76%, a specificity of 98% and an accuracy of 93%. On the other hand, for X-ray CT a sensitivity of 65%, a specificity of 87% and an accuracy of 82% were observed. A significant difference was observed in respect of both specificity and accuracy (P<0.05). Based on the above findings, FDG PET is suggested to be superior to X-ray CT when used for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer.