High resolution endoluminal ultrasonography in the staging of esophageal carcinoma

Endoscopic ultrasound: it's accuracy in evaluating mediastinal lymphadenopathy? A meta-analysis and systematic review

AIM

To evaluate the accuracy of endoscopic ultrasound (EUS), EUS-fine needle aspiration (FNA) in evaluating mediastinal lymphadenopathy.

METHODS

Only EUS and EUS-FNA studies confirmed by surgery or with appropriate follow-up were selected. Articles were searched in Medline, Pubmed, and Cochrane control trial registry. Only studies from which a 2 multiply 2 table could be constructed for true positive, false negative, false positive and true negative values were included. Two reviewers independently searched and extracted data. The differences were resolved by mutual agreement. Meta-analysis for the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Pooling was conducted by both Mantel-Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). The heterogeneity of studies was tested using Cochran's Q test based upon inverse variance weights.

RESULTS

Data was extracted from 76 studies (n = 9310) which met the inclusion criteria. Of these, 44 studies used EUS alone and 32 studies used EUS-FNA. FNA improved the sensitivity of EUS from 84.7% (95% CI: 82.9-86.4) to 88.0% (95% CI: 85.8-90.0). With FNA, the specificity of EUS improved from 84.6% (95% CI: 83.2-85.9) to 96.4% (95% CI: 95.3-97.4). The P for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10.

CONCLUSION

EUS is highly sensitive and specific for the evaluation of mediastinal lymphadenopathy and FNA substantially improves this. EUS with FNA should be the diagnostic test of choice for evaluating mediastinal lymphadenopathy.

Staging accuracy of esophageal cancer by endoscopic ultrasound: A meta-analysis and systematic review

AIM: To evaluate the accuracy of endoscopic ultrasound (EUS) in the staging of esophageal cancer.

METHODS: Only EUS studies confirmed by surgery were selected. Articles were searched in Medline and Pubmed. Two reviewers independently searched and extracted data. Meta-analysis of the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratio. Pooling was conducted by both the Mantel-Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). The heterogeneity of studies was tested using Cochran’s Q test based upon inverse variance weights.

RESULTS: Forty-nine studies (n = 2558) which met the inclusion criteria were included in this analysis. Pooled sensitivity and specificity of EUS to diagnose T1 was 81.6% (95% CI: 77.8-84.9) and 99.4% (95% CI: 99.0-99.7), respectively. To diagnose T4, EUS had a pooled sensitivity of 92.4% (95% CI: 89.2-95.0) and specificity of 97.4% (95% CI: 96.6-98.0). With Fine Needle Aspiration (FNA), sensitivity of EUS to diagnose N stage improved from 84.7% (95% CI: 82.9-86.4) to 96.7% (95% CI: 92.4-98.9). The P value for the χ² test of heterogeneity for all pooled estimates was > 0.10.

CONCLUSION: EUS has excellent sensitivity and specificity in accurately diagnosing the TN stage of esophageal cancer. EUS performs better with advanced (T4) than early (T1) disease. FNA substantially improves the sensitivity and specificity of EUS in evaluating N stage disease. EUS should be strongly considered for staging esophageal cancer.

Preoperative TN staging of esophageal cancer: Comparison of miniprobe ultrasonography, spiral CT and MRI

AIM: To evaluate the value of miniprobe sonography (MPS), spiral CT and MR imaging (MRI) in the tumor and regional lymph node staging of esophageal cancer.

METHODS: Eight-six patients (56 men and 30 women; age range of 39-73 years, mean 62 years) with esophageal carcinoma were staged preoperatively with imaging modalities. Of them, 81 (94%) had squamous cell carcinoma, 4 (5%) adenocarcinoma, and 1 (1%) adenoacanthoma. Eleven patients (12%) had malignancy of the upper one third, 41 (48%) of the mid-esophagus and 34 (40%) of the distal one third. Forty-one were examined by spiral CT in whom 13 were co-examined by MPS, and forty-five by MRI in whom 18 were also co-examined by MPS. These imaging results were compared with the findings of the histopathologic examination for resected specimens.

RESULTS: In staging the depth of tumor growth, MPS was significantly more accurate (84%) than spiral CT and MRI (68% and 60%, respectively, P < 0.05). The specificity and sensitivity were 82% and 85% for MPS; 60% and 69% for spiral CT; and 40% and 63% for MRI, respectively. In staging regional lymph nodes, spiral CT was more accurate (78%) than MPS and MRI (71% and 64%, respectively), but the difference was not statistically significant. The specificity and sensitivity were 79% and 77% for spiral CT; 75% and 68% for MPS; and 68% and 62% for MRI, respectively.

CONCLUSION: MPS is superior to spiral CT or MRI for T staging, especially in early esophageal cancer. However, the three modalities have the similar accuracy in N staging. Spiral CT or MRI is helpful for the detection of far-distance metastasis in esophageal cancer.

Endoluminal sonography of the genitourinary and gastrointestinal tracts

OBJECTIVE

Endoluminal sonography with high-frequency catheter-based transducers is a technique well suited to imaging structures beyond the lumen of the hollow viscus. The purpose of this article was to review some aspects of endoluminal sonography, including instrumentation, clinical applications in the gastrointestinal and genitourinary tracts, and its three-dimensional reconstruction.

METHODS

The development of 6F to 10F catheter-based ultrasonic probes has made this technique available for use within a variety of lumina. Endoluminal sonography with frequencies of 9 to 20 MHz has been used for evaluation of a wide range of abnormalities in both the genitourinary and gastrointestinal tracts.

RESULTS

Uses in the gastrointestinal tract include quantification of esophageal varices, distinguishing between various submucosal lesions, and measuring the degree of fibrosis in scleroderma. In the genitourinary system, endoluminal sonography has been used to guide collagen injection, to diagnose urethral diverticula and upper tract neoplasms, to locate crossing vessels and septa for guiding endopyelotomy, and to identify submucosal calculi.

CONCLUSIONS

High-resolution endoluminal sonography is a new sonographic approach for evaluation of the genitourinary and gastrointestinal tracts. This should lead to the expansion of the diagnostic capabilities of sonography, providing important information for decision making relative to patient care and minimally invasive interventional procedures. Reconstructed three-dimensional endoluminal sonography has the potential to become a valuable tool in both the research and clinical areas.

Endosonographic staging of 100 consecutive patients with esophageal carcinoma: introduction of the 8-mm esophagoprobe

Endoscopic ultrasound of esophageal carcinoma is conventionally performed using the 13-mm fiberoptic/ultrasound echoendoscope. However, the large diameter results in an inability to negotiate the primary tumor in 25% of patients. The aim of this study was first to determine whether use of the 8-mm esophagoprobe would overcome this problem and second to evaluate the accuracy of the smaller diameter instrument. One hundred consecutive patients with esophageal cancer underwent initial gastroscopy. Based upon the degree of luminal stenosis, patients were staged with either the conventional echoendoscope (luminal diameter > or = 15 mm) or the esophagoprobe (luminal diameter < 15 mm). The primary tumor was successfully negotiated in all subjects (echoendoscope 30, esophagoprobe 70) so that T- and N-staging was accomplished in every patient. Esophageal dilatation was performed in 12 patients (12%). The procedure was well tolerated and there were no complications, in particular no patient suffered esophageal perforation. The accuracy of the esophagoprobe for T-staging was 90% (19 out of 20) and that for N-staging was 75% (15 out of 20). This was similar to the accuracy of staging with the conventional echoendoscope, 90% (9 out of 10) for T-stage and 90% (9 out of 10) for N-stage. The esophagoprobe can safely and accurately stage patients with esophageal carcinoma, including those with high-grade stenoses.

Staging of oesophageal carcinoma with high resolution endoluminal ultrasonography

Oesophageal carcinoma is a disease with poor prognosis despite improved treatment and diagnostic methods. The most important prognostic features are the degree of wall invasion and the presence of lymph node metastasis. Endoscopic ultrasonography (EUS) in the region of 7.5-12 MHz has improved the accuracy of tumour staging. In the course of 1 year, 21 patients with oesophageal carcinoma were examined with 20 MHz high-resolution intraluminal ultrasonography (HRES). In 11 (52%) patients, both ultrasound catheter and fiber gastroscope could pass the tumour, in 5 (23%) only the ultrasound catheter could pass. In the remaining patients the ultrasound catheter could only partially pass without prior dilatation. One patient was classified as having a stage T2 tumour, 14 (67%) had T3 and 4 (19%) had T4. In 2 patients the tumour could not be fully classified but was at least T3 When comparing our results with findings at computed tomography (CT), the T stage coincided in 9 patients (42%), in 9 patients (42%) CT could not differentiate between T2 and T3 and in 3 investigations HRES showed a higher T stage than CT. In 3 patients (14%) ultrasonography found N1 stage where CT staged N0. In one patient, CT found lymph nodes not seen with HRES. Further studies comparing EUS, HRES and surgical findings are planned to assess our view that HRES is a useful method in preoperative staging of oesophageal carcinoma.

Endosonographic evaluation of the patient with esophageal cancer

The prognosis for patients with carcinoma of the esophagus remains poor despite the recent use of aggressive combination therapies and radical surgical resection. Attempts to improve the survival of patients with esophageal carcinoma have been confounded by a lack of effective therapeutic options in the later stages of the disease and an inability to accurately identify the early disease stages. Endoscopic ultrasound is a novel technique that affords close-proximity imaging of the esophageal wall and its adjacent structures. Endosonography is superior to CT scan for assessing depth of tumor penetration (T stage) and lymph node status (N stage). Recent advances in endoscopic ultrasonography include the ability to perform ultrasound-guided fine-needle aspiration of mediastinal masses and lymph nodes. Therefore, endosonography is ideally suited for staging esophageal cancers.

Relationship between histological type and endosonographic detection of regional lymph node metastases in gastric cancer

The aim of the study was to compare the ability of endoscopic ultrasonography (EUS) in detecting lymph node metastases in differentiated and undifferentiated gastric adenocarcinoma. EUS was performed in 149 patients with differentiated or undifferentiated gastric cancer. Histopathological findings were compared with pre-operative EUS findings in a total of 2961 resected lymph nodes. The EUS detection rates of metastasis to individual nodes in relation to node size, the ratio of the metastasized area to the cross-sectional area of the node and to the depth of primary tumour invasion, were also investigated. The accuracy and negative predictive values of EUS for detecting metastatic lymphadenopathy in each patient were significantly higher for differentiated (87%, 94%) than for undifferentiated (71%, 71%) tumours. The detection rate of individual node metastasis was higher for differentiated (31%) than for undifferentiated (21%) tumours. For differentiated lesions, EUS detected more small nodal metastases (< 5 mm in diameter) (p < 0.01) and more nodes involved with a relatively small proportion of the metastasized area to the cross-sectional area of the node (< 1/3 involvement) (p < 0.05). In relatively superficial lesions, such as pT1 and pT2, the pre-operative EUS detection rate of metastatic nodes was higher for differentiated than for undifferentiated tumours. In conclusion, the ability of EUS to detect nodal metastases is related to the histological type of gastric cancer.