螺旋CT扫描对胃癌淋巴结转移的术前评估

目的:评估螺旋CT扫描对显示胃癌淋巴结转移的应用价值.材料和方法:76例经上消化道造影或胃镜诊断的胃癌患者,术前行水充盈法螺旋CT三期扫描;CT所见与手术病理结果对照.结果:螺旋CT扫描对胃癌淋巴结转移显示的敏感性为70%,特异性达79.2%;淋巴结的大小、形态及强化特征有助于阳性淋巴结的诊断.结论:螺旋CT扫描术前评估胃癌淋巴结转移有较大的临床应用价值.     

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.     

Morphologic predictors of lymph node status in rectal cancer with use of high-spatial-resolution MR imaging with histopathologic comparison

PURPOSE: To evaluate signal intensity and border characteristics of lymph nodes at high-spatial-resolution magnetic resonance (MR) imaging in patients with rectal cancer and to compare these findings with size in prediction of nodal status. MATERIALS AND METHODS: Forty-two patients who underwent total mesorectal excision of the rectum to determine if they had rectal carcinoma were studied with preoperative thin-section MR imaging. Lymph nodes were harvested from 42 transversely sectioned surgical specimens. The slice of each lymph node was carefully matched with its location on the corresponding MR images. Nodal size, border contour, and signal intensity on MR images were characterized and related to histologic involvement with metastases. Differences in sensitivity and specificity with border or signal intensity were calculated with CIs by using method 10 of Newcombe. RESULTS: Of the 437 nodes harvested, 102 were too small (<3 mm) to be depicted on MR images, and only two of these contained metastases. In 15 (68%) of 22 patients with nodal metastases, the size of normal or reactive nodes was equal to or greater than that of positive nodes in the same specimen. Fifty-one nodes were above the area imaged, and seven of these contained metastases. The diameter of benign and malignant nodes was similar; therefore, size was a poor predictor of nodal status. If a node was defined as suspicious because of an irregular border or mixed signal intensity, a superior accuracy was obtained and resulted in a sensitivity of 51 (85%) of 60 (95% CI: 74%, 92%) and a specificity of 216 (97%) of 221 (95% CI: 95%, 99%). CONCLUSION: Prediction of nodal involvement in rectal cancer with MR imaging is improved by using the border contour and signal intensity characteristics of lymph nodes instead of size criteria.     

Value of 11C-choline PET and contrast-enhanced CT for staging of bladder cancer: correlation with histopathologic findings.

Lymph node involvement is a major prognostic factor in bladder cancer, but the accuracy of conventional imaging modalities for the prediction of regional and distant metastatic diseases is limited. This study was performed to compare the diagnostic accuracies of contrast-enhanced CT and PET with (11)C-choline for the staging of urothelial bladder cancer. METHODS: Twenty-seven patients (median age, 69.1 y) who had urothelial bladder cancer and who were referred for radical cystectomy and pelvic lymph node dissection (PLND) on the basis of a histologic evaluation after transurethral resection of bladder cancer (TURB) were studied. PET scanning, using 2 multiring whole-body tomographs, was performed 5 min after intravenous injection of approximately 370-500 MBq of (11)C-choline. In addition, conventional bone scintigraphy and contrast-enhanced CT were performed. After imaging, cystectomy and PLND were performed in all patients. Pathologic (11)C-choline uptake that could not be explained by intestinal activity was noted as a positive result. Node positivity was determined by size on CT: nodes measuring more than 1 cm in the long axis were described as being positive for tumor. Histopathologic findings were used as a reference. RESULTS: The presence of residual bladder cancer (pTa-pT4) was correctly detected in 21 of 25 histologically tumor-positive patients (84%) by CT and in 24 of 25 patients (96%) by (11)C-choline PET. Lymph node involvement was correctly detected in 4 of 8 patients (50%) by CT and in 5 of 8 patients (62%) by (11)C-choline PET. The median size of the 3 nodes with false-negative PET results was 9 mm (range, 6-21 mm), and the median size of the metastatic lesions within the lymph nodes was 3 mm (range, 1-15 mm). CT resulted in 6 (22%) false-positive lymph nodes, whereas none was demonstrated by (11)C-choline PET; these data indicated a significantly higher accuracy of PET than of CT (P < 0.01). Both modalities missed a small peritoneal metastasis verified by histologic evaluation. No positive results were obtained from bone scintigraphy. CONCLUSION: These preliminary data suggest that (11)C-choline PET is comparable to CT for detecting residual bladder cancer after TURB but appears to be superior to CT for the evaluation of potential additional lymph node metastases. (11)C-choline PET should be further evaluated for staging in patients who have bladder cancer and who are scheduled for radical cystectomy.     

Diagnostic reliability of ultrasonography in the preoperative staging of the N parameter in head and neck neoplasms

The demonstration of metastatic involvement of neck nodes is a crucial step in the staging of patients with head and neck tumors. Diagnostic accuracy, sensitivity, and specificity of US in the detection of lymph node metastases were evaluated in 48 patients with this type of malignancy. The patients subsequently underwent surgical node dissection. Comparison of US, clinical and histological data demonstrated US to have 93.7% diagnostic accuracy, 100% sensitivity, and 84% specificity--the corresponding clinical values being 81%, 79%, and 84%, respectively. Among several US parameters, a substantial role in differentiating metastatic from tumor-free lymph nodes was played by the evaluation of roundness index (RI), and by the demonstration of an intranodal hyperechoic stria: RI value was always higher than 2 in tumor-free nodes and the hyperechoic stria was always absent in metastatic nodes. US approach never failed to demonstrate metastatic nodes while clinics missed them in 6 patients. Thus, US appears the most valuable diagnostic tool for staging head and neck tumors; its diagnostic accuracy can be increased by the combination with US-guided aspiration biopsy.     

Role of axillary lymph node ultrasound and large core biopsy in the preoperative assessment of patients selected for sentinel node biopsy

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of axillary lymph node sonography, if necessary in combination with US-guided large core biopsy, in the preoperative evaluation of breast cancer patients scheduled for quadrantectomy and sentinel lymph node excision. MATERIALS AND METHODS: From July 2001 to December 2002, we evaluated 117 breast cancer patients with ultrasound and, where indicated, FNAB. Breast lesions had diameters between 4 and 26 mm (mean diameter 11 mm). Fifteen (13%) of the 117 patients were excluded from the series as they did not fulfil the criteria for preliminary sonography of the axilla: in 9 patients fewer than 4 nodes were detected and in 6 patients the breast lesions were intraoperatively found to be benign. Eleven patients (10.7 %) with sonographically suspicious axillary nodes were sampled by US-guided core biopsy using a 14 or 16 Gauge Tru-Cut needle. RESULTS: The ultrasound study aims to evaluate the dimensions and morphology of the breast lesion as well as detect and assess at least 4 axillary nodes. These were evaluated for hilar and cortical thickening and ratio between the sinus diameter and the total longitudinal diameter. Lymph nodes with hilar diameters equal to or greater than 50% of the longitudinal diameter were considered normal. Of the 102 patients evaluated, 77 (75.7%) had normal axillary nodes according to the US criteria adopted. Negativity was confirmed by histology in 56 cases (72.7%, true negative); 21 (27.3%, false negative) were found to be positive, in contrast with the sonographic appearance. The false negative cases were due to lymph node micrometastasis which probably did not cause morphologic alterations perceptible at ultrasound. The remaining 25 patients (24.5%) had axillary lymph nodes classified as suspicious. In 13 cases of (52%, true positive) there was agreement with histology, whereas in 12 cases (48%, false positive) the US suspicion was not confirmed at surgery. The most important sonographic alteration was the gradual reduction in hilar echogenicity (seen in 100% metastatic nodes); conversely, hilar denting or irregularities, as well as dimensional criteria, proved to be poorly specific. CONCLUSIONS: The sonographic assessment of axillary and internal mammary chain nodes, possibly in addition to core biopsy, improves the preoperative evaluation of breast cancer patients scheduled for conservative surgery of the breast (quadrantectomy) and the axilla (sentinel node biopsy). US findings suspicious for metastatic involvement of axillary lymph nodes should be considered as an exclusion criterion for sentinel node biopsy. A more widespread use of axillary node biopsy and an accurate sonographic evaluation of the excised lymph node increase the specificity of the procedure, allowing a better correlation between sonographic findings and definitive histology.     

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.     

胃癌介入治疗的疗效评价探讨

目的　评价胃癌介入治疗疗效评价更为可靠的标准。方法　分析病理证实的１０４ 例无手术指征的胃癌患者（ 含术后复发） 、影像诊断胃癌同时检出其他部位转移而无病理诊断者４３ 例，行胃动脉内化疗栓塞、转移灶化疗栓塞。术后用ＣＴ、ＧＩ和胃镜随访病灶。采用ＣＯＸ 肿瘤生存模型进行生存随访。结果　１ ． 胃癌原发灶治疗后，明显的缩小占６０．８ ％ ，２３．２ ％ 无明显反应，１７％ 在治疗中途出现病灶增大或转移至其他部位；ＣＴ随访碘化油沉积越浓，占肿瘤体积比例越大，滞留时间越长，肿瘤缩小越明显。淋巴结和转移灶在动脉内化疗栓塞后均有程度不等的缩小。２ ．１４７ 例患者中，至今存活５７ 例。首次治疗距统计日已满１２ 月者８５ 例，大于１２ 月者７９ 例，占５３ ．７％ （７９／１４７）；距统计日２４ 月者９４ 例，生存期等于或大于３６ 月者１９ 例，占１２．９ ％ ；距统计日５ 年以上者３１ 例，存活５ 年以上者９ 例，占６１．２％ 。结论　胃癌病灶介入治疗评价应包括原发灶、转移灶和淋巴结的改变，单纯以大小改变不能准确反映治疗疗效，更为主要的是肿瘤内部结构的变化。同时作者提出非肿块病灶缩小率的评价标准。     

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.     

Identification of inguinal lymph node metastases from vulval carcinoma by magnetic resonance imaging: an initial report

AIM: Magnetic Resonance Imaging (MRI) has the potential to assess inguinal lymph nodes more accurately than palpation and less invasively than surgical exploration. The objective of this study was to measure the accuracy of MRI in identifying inguinal metastases by demonstrating abnormal lymph node morphology. MATERIALS AND METHODS: 10 women with vulval malignancy underwent T1- and fat-suppressed T2-weighted surface coil MRI of both groins before surgery. Each groin was prospectively categorised as normal or as having metastatic lymphadenopathy using criteria established in normal volunteers. Histopathological findings in patients undergoing groin dissection for invasive vulval carcinoma were used as validation. RESULTS: MRI had a positive predictive value of 89%, negative predictive value of 91%, sensitivity of 89%, specificity of 91% and accuracy of 90%. The most useful observations on MRI to identify metastatic lymphadenopathy were those of lymph node contour irregularity, cystic change in a lymph node, short axis diameter exceeding 10mm and abnormal long: short axis diameter ratio. CONCLUSION: High resolution MRI of the inguinal regions has potential to screen for lymph node metastases in patients with vulval cancer, with the aim of reducing the number of women who have to undergo groin dissection.     

Evaluation of lymph node metastases of breast cancer using ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance imaging

BACKGROUND: We assessed the utility of enhanced magnetic resonance imaging (MRI) using ultrasmall superparamagnetic iron oxide (USPIO) in the evaluation of axillary lymph node metastases in patients with breast cancer. STUDY DESIGN: MR examination of the axilla was performed before and 24-36 h after USPIO administration for patients with stage II or III breast cancer. Diagnostic performance was compared using size criteria (metastasis was defined when short axis diameter >5 or >10mm) or morphologic criteria on conventional MRI, the combined study of USPIO precontrast and postcontrast images, and USPIO postcontrast study alone. RESULTS: A total of 622 nodes (503 metastatic and 119 nonmetastatic nodes) were dissected from 33 patients. The results of conventional MRI for nodes >5mm were 59.1% sensitivity, 86.7% specificity, and 80.4% overall accuracy. Results for nodes >10mm were 15.7% sensitivity, 99.2% specificity, and 80.2% overall accuracy. Results based on morphology were 36.5% sensitivity, 94.1% specificity, and 81.0% overall accuracy. The results of the combined study of USPIO precontrast and postcontrast images were 86.4% sensitivity, 97.5% specificity, 91.1% positive predictive value, 96.1% negative predictive value, and 95.0% overall accuracy. The results of USPIO postcontrast images alone were 84.7% sensitivity, 96.8% specificity, and 94.0% overall accuracy. Patient-based results of postcontrast USPIO study alone were 100.0% sensitivity, 80.0% specificity, and 93.9% overall accuracy. CONCLUSIONS: USPIO postcontrast study alone was useful in the assessment of axillary lymph node metastases in patients with breast cancer.     

Lymph node staging of gastric cancer using (18)F-FDG PET: a comparison study with CT.

This study was performed to compare (18)F-FDG PET with CT for the evaluation of primary tumors and lymph node metastases in gastric cancer. METHODS: Eighty-one patients (28 women and 53 men; mean age, 56.6 y; age range; 32-82 y) who had undergone radical (n = 74) or palliative (n = 7) gastrectomy and lymph node dissection for the management of gastric cancer were included. Preoperative (18)F-FDG PET and CT were reviewed retrospectively for primary tumors of the stomach and lymph node metastases. Any increased (18)F-FDG uptake exceeding that of the adjacent normal gastric wall was considered positive for the primary tumor. Lymph nodes were classified into 3 groups based on their anatomic sites. Because perigastric lymph nodes (N1) were often not clearly differentiated from primary tumors, N1 lymph node metastases were determined when possible. Lymph nodes were considered positive or negative on the basis of the group as a whole. Final conclusions for primary tumors and lymph node metastases were based on histopathologic specimens in all patients. RESULTS: There were 17 patients with early gastric cancer (EGC) and 64 patients with advanced gastric cancer (AGC). For primary tumors, both PET and CT showed a sensitivity of 47% (8/17) for EGC and 98% (63/64) for AGC. The sensitivity of CT for N1 disease was significantly higher than that of PET. (18)F-FDG PET had a sensitivity, specificity, and accuracy of 34% (11/32), 96% (47/49), and 72% (58/81), respectively, for N2 metastases, whereas the corresponding CT values were 44% (14/32), 86% (42/49), and 69% (56/81). For N3 metastases, PET and CT had the same sensitivity, specificity, and accuracy: 50% (3/6), 99% (74/75), and 95% (77/81), respectively. Overall, the sensitivity, specificity, and accuracy of (18)F-FDG PET were not significantly different from those of CT for primary tumors or for N2 and N3 metastases. CONCLUSION: (18)F-FDG PET is as accurate as CT for the detection of primary tumors of either EGC or AGC. The low sensitivities of PET and CT were insufficient to allow decision making on the extent of lymphadenectomy. In contrast, the high specificity of PET for N disease appeared valuable, and the presence of N disease on PET may have a clinically significant impact on the choice of initial therapy.     

螺旋CT增强扫描对食管癌淋巴结转移的诊断价值

目的探讨多层螺旋CT(MSCT)强化扫描评价食管癌淋巴结转移的价值。方法35例食管癌患者行MSCT增强扫描(安射力(320mg/100ml)90ml,注射速度2.5ml/s,延迟55s扫描),扫描范围从舌骨水平至肝下缘,将原始数据重建为层厚1.25mm,层间隔1mm,应用多平面重建(MPR)进行图像后处理。CT扫描以气管食管沟淋巴结短径大于5mm、其余区域淋巴结及腹腔淋巴结短径大于10mm为转移标准统计。淋巴结分组按照Korst提出的食管癌淋巴结简化分组标准进行分组。所有患者均接受手术治疗,切除组织均经病理证实。以病理结果为标准,分析MSCT在诊断食管癌淋巴结转移方面的灵敏度、特异度、准确率。结果35例食管癌患者中鳞癌33例,腺癌1例,鳞腺癌1例,手术共清除淋巴结318枚,病理证实66枚有转移。MSCT共诊断淋巴结转移74枚,正确诊断56枚转移淋巴结,其灵敏度、特异度、准确率分别为84.8%、92.9%、91.2%。结论MSCT强化扫描发现食管癌淋巴结转移有较高的准确性和特异性,可为临床术前确定治疗方案提供重要的帮助。     

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.     

Mediastinal lymph node size in lung cancer

Using a size criterion of 1 cm or greater as evidence for abnormality, the size of mediastinal lymph nodes identified by computed tomography (CT) was a poor predictor of mediastinal lymph node metastases in a series of 86 patients who had surgery for bronchogenic carcinoma. The surgery included full nodal sampling in all patients. Of the 86 patients, 36 had nodes greater than or equal to 1 cm identified by CT. Of the 21 patients with mediastinal metastases proven at surgery, 14 had nodes greater than or equal to 1 cm (sensitivity = 67%). Of the 65 patients without mediastinal metastases, 22 had nodes greater than or equal to 1 cm. Specificity was 66% (43/65). Obstructive pneumonia and/or pulmonary collapse distal to the cancer was present in 39 patients (45%). Of these, 21 had mediastinal nodes greater than or equal to 1 cm; 10 harbored metastases and 11 did not. Obstructive pneumonia and/or pulmonary collapse is a common occurrence in bronchogenic carcinoma, but mediastinal nodes greater than or equal to 1 cm in this circumstance cannot be presumed to represent metastatic disease. Metastatic mediastinal lymph node involvement was related to nodal size also in patients with evidence of prior granulomatous disease and in patients with no putative benign cause for nodes greater than or equal to 1 cm. In both of these groups, metastatic nodal disease was found in only 25% of nodes greater than or equal to 1 cm.     

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.     

Percutaneous ethanol injection for treatment of cervical lymph node metastases in patients with papillary thyroid carcinoma

OBJECTIVE: The objective of this study was to evaluate the technique, efficacy, and side effects of percutaneous ethanol injection in patients with limited cervical nodal metastases from papillary thyroid carcinoma. SUBJECTS AND METHODS: Fourteen patients who had undergone thyroidectomy for papillary thyroid carcinoma presented with limited nodal metastases (one to five involved nodes) in the neck between May 1993 and April 2000. All patients had received previous iodine-131 ablative therapy with a mean total dose per patient of 7,548 MBq. Ten of the patients either were considered poor surgical candidates or preferred not to have surgery, and all were unresponsive to iodine-131 therapy. Each metastatic lymph node was treated with percutaneous ethanol injection, and patients received both clinical and sonographic follow-up. RESULTS: Twenty-nine metastatic lymph nodes in our 14 patients were injected. Mean sonographic follow-up was 18 months (range, from 2 months to 6 years 5 months). All treated lymph nodes decreased in volume from a mean of 492 mm(3) before percutaneous ethanol injection to a mean volume of 76 mm(3) at 1 year and 20 mm(3) at 2 years after treatment. Six nodes were re-treated 2-12 months after initial percutaneous ethanol injection because of persistent flow on color Doppler sonography (n = 4), stable size (n = 1), or increased size (n = 1). Two patients developed four new metastatic nodes during the follow-up period that were amenable to percutaneous ethanol injection. Two patients developed innumerable metastatic nodes that precluded retreatment with percutaneous ethanol injection. No major complications occurred. All patients experienced long-term local control of metastatic lymph nodes treated by percutaneous ethanol injection. In 12 of 14 patients, percutaneous ethanol injection was successful in controlling all known metastatic adenopathy. CONCLUSION: Sonographically guided percutaneous ethanol injection is a valuable treatment option for patients with limited cervical nodal metastases from papillary thyroid cancer who are not amenable to further surgical or radioiodine therapy.     

Lymphoscintigraphy in patients with malignant melanoma: a quantitative and qualitative evaluation of its usefulness

Lymphoscintigraphy using 99mTcSb2S3 colloid was performed in 32 patients with malignant melanoma. Subcutaneous injections were made peritumorally in 20 patients and dorsopedally in 12 patients. Regional lymph node dissections were carried out on the following day in 16 patients and the resected lymph nodes were weighted, measured for radioactivity, and examined by light microscopy. Lymph flow to regional lymph nodes was shown in all but 2 patients. Twenty-nine of 239 lymph nodes contained metastases. Radioactivity was demonstrated in 17 of these nodes. In 5 of 11 patients with metastatic disease, the highest uptake was found in cancerous lymph nodes. The specific activity-uptake distribution in isolated ilio-inguinal lymph nodes after a dorsopedal injection was log-normal with a mean of 0.05%/g indicating a good saturation of colloid particles. This investigation concludes that the observed lymph flow directions in patients injected peritumorally are of value for the follow-up. Quantitative lymphoscintigraphy in patients with melanoma of the lower extremities is, however, of no value for excluding ilio-inguinal lymph node metastases.     

直肠周围间隙淋巴结转移的术前MSCT评估

目的:分析直肠周围间隙淋巴结转移的多层CT(MSCT)表现,探讨CT诊断直肠癌淋巴结转移(N分期)的价值.方法:术前行盆腔MSCT检查的154例直肠癌病例,均行全直肠系膜切除术,对直肠周围间隙淋巴结进行病理检查,采用双盲法,记录每枚淋巴结的CT表现,包括淋巴结短轴直径、边缘、密度、分布方式.结果:以手术病理为标准.直肠周围间隙淋巴结CT检出率为86.3%(471/546),病理共检出直肠周围间隙淋巴结546枚,CT检出481枚,其中471枚(阳性172枚,阴性299枚)淋巴结与病理相匹配.CT诊断直肠周围间隙淋巴结转移的各种判断标准(淋巴结大小、边缘、密度、分布方式)的敏感性分别为83.1%、72.2%、70.1%、73.5%,特异性分别为80.5%、85.1%、82.4%、75.1%.CT显示的淋巴结大小、边缘、密度、分布方式的差异与阳性率有显著相关性,P<0.005.结论:直肠周围间隙淋巴结有良性和恶性淋巴结,综合分析淋巴结大小、形态、密度及分布对诊断直肠周围间隙淋巴结转移有很大帮助.     

Mesenteric lymph nodes: detection and significance on MDCT

OBJECTIVE: Unsuspected mesenteric lymph nodes are frequently found on abdominal CT scans in everyday clinical practice. What to do with these findings has not been well established. The purpose of this study is to document the incidence of mesenteric lymph nodes in a previously healthy population and to provide guidelines for further management. MATERIALS AND METHODS: We examined the CT scans of 132 consecutive patients (84 men and 36 women; age range, 12-90 years; mean age, 43 years) who presented to the emergency department after experiencing blunt abdominal trauma. Twelve patients were excluded because they had disease processes known to be associated with lymphadenopathy. All imaging was performed using 3.2-mm collimation on MDCT scanners with IV contrast material. Two radiologists evaluated the images by consensus and recorded the presence of mesenteric lymph nodes greater than 3 mm in the short axis. Lymph node size, number, and location (central, peripheral, or right lower quadrant) were documented. All studies were reviewed on a PACS workstation. RESULTS: Of the 120 patients with otherwise normal CT scans, 47 had mesenteric lymph nodes greater than 3 mm. Of these 47 patients, 22 (47%) had five or more lymph nodes detected. Twenty-five (53%) of the 47 patients had four or fewer nodes. The mean size of the largest nodes was 4.8 mm (range, 3-9 mm), and the mean size of the nodes found per patient was 3.6 mm (range, 3-6 mm). These nodes were identified only at the mesenteric root in 32 patients (68%), only in the mesenteric periphery in eight patients (17%), and only in the right lower quadrant in five patients (11%). Nodes were identified in more than one location in two patients (4%). CONCLUSION: Incidental finding of mesenteric lymph nodes is common, reflecting more widespread use of thin-collimation MDCT and PACS workstations. In general, these nodes are small, measuring less than 5 mm. Such nodes when found in an otherwise healthy population are clinically insignificant and require no further imaging.