Comparison of a linear miniature ultrasound probe and a radial-scanning echoendoscope in TN staging of esophageal cancer

Endoscopic Ultrasound in Cancer Staging

The authors review the role of endoscopic ultrasound (EUS) in the staging of cancers throughout the gastrointestinal tract. EUS offers an advantage over cross-sectional imaging in locoregional tumor staging but is less sensitive in identifying distant metastasis. The addition of FNA increases diagnostic accuracy and provides a tissue diagnosis. EUS combined with cross-sectional imaging is important in accurately staging GI tumors and thereby reducing unnecessary procedures and health care costs.

Accuracy of endoscopic ultrasound in esophageal cancer staging

Since its advent in the 1980s endoscopic ultrasound (EUS) has played an important role in the diagnosis, staging, and therapeutic management of various gastrointestinal malignancies. EUS has emerged as a vital tool in the evaluation of esophageal cancer as it provides a detailed view of the layers of the esophageal wall and surrounding tissues. This permits determination of tumor invasion depth and local lymph node metastases. It is the most sensitive and specific method available for locoregional staging of esophageal cancer. The information obtained via EUS is vital in determining the appropriate diagnosis, prognosis, and treatment options. Thus, this article aims to present a review of the accuracy and utilization of EUS in the staging of esophageal cancer.

Endoscopic ultrasonography for preoperative staging of esophageal carcinoma

OBJECTIVE

To evaluate the diagnostic value of endoscopic ultrasonography (EUS) in preoperative staging of esophageal carcinoma (EC).

MATERIAL AND METHODS

A total of 86 surgical patients with EC who were confirmed by endoscopy and biopsy underwent preoperative TN staging with EUS examination. The EUS findings were compared with surgical pathologic results.

RESULTS

The accuracy of EUS in T and N staging of EC was 82.6% and 84.9%, respectively. While determining whether EC invades the muscularis propria or outer membrane, EUS had the favorable sensitivity, specificity, positive predictive value and negative predictive value. The short-axis diameter of lymph nodes of 5mm had high sensitivity and negative predictive value to determine malignance with low specificity and positive predictive value. The short-axis diameter of 10mm presented the satisfactory sensitivity, specificity, positive predictive value and negative predictive value.

CONCLUSION

EUS can accurately determine the TN staging of EC and provide a reliable basis for the treatment of EC.

Endoscopic Ultrasound for Preoperative Esophageal Squamous Cell Carcinoma: a Meta-Analysis

Background

Treatment options and prognosis of esophageal squamous cell carcinoma (ESCC) depend on the primary tumor depth (T-staging) and regional lymph node status (N-staging). Endoscopic ultrasound (EUS) has emerged as a useful staging tool, but studies regarding its benefits have been variable. The objective of this study was to evaluate the diagnostic accuracy of EUS for detecting preoperative ESCC.

Methods

We included in our meta-analysis studies involving EUS-based staging of preoperative ESCC compared with pathological staging. Using a random-effects model, we performed a meta-analysis of the accuracy of EUS by calculating pooled estimates of sensitivity, specificity and the diagnostic odds ratio. In addition, we created a summary receiver operating characteristic (SROC) curve.

Results

Forty-four studies (n = 2880) met the inclusion criteria. The pooled sensitivity and specificity of T1 were 77% (95%CI: 73 to 80) and 95% (95%CI: 94 to 96). Among the T1 patients, EUS had a pooled sensitivity in differentiating T1a and T1b of 84% (95%CI: 80 to 88) and 83% (95%CI: 80 to 86), and a specificity of 91% (95%CI: 88 to 94) and 89% (95%CI: 86 to 92). To stage T4, EUS had a pooled sensitivity of 84% (95%CI: 79 to 89) and a specificity of 96% (95%CI: 95 to 97). The overall accuracy of EUS for T-staging was 79% (95%CI: 77 to 80), and for N-staging, 71% (95%CI: 69 to 73).

Conclusions

EUS has good diagnostic accuracy for staging ESCC, which has better performance in T1 sub-staging (T1a and T1b) and advanced disease (T4).

Diagnostics and Early Diagnosis of Esophageal Cancer

In the esophagus two different kinds of primary neoplasias may arise: squamocellular carcinomas (SCC) and esophageal adenocarcinomas (EAC). Although both types of carcinoma are rare diseases, especially the incidence of EAC rose in the last years. The management of esophageal cancer is challenging. There are no specific symptoms of early esophageal cancers. Due to this fact, most of the esophageal cancers are found incidentally, and only 12.5% of esophageal tumors are endoscopically resectable. Gastroscopy is the gold standard for the diagnosis of esophageal cancer. The sensitivity of detecting early-stage carcinoma may be improved by adjunct techniques such as chromoendoscopy, virtual chromoendoscopy, magnification endoscopy, and other advanced endoscopic imaging techniques. The diagnosis of esophageal cancer can be verified with targeted biopsies. Accurate staging information is crucial for establishing appropriate treatment choices for esophageal cancer, while the depth of the tumor determines the feasibility of therapy. In terms of staging, endosonography, abdominal ultrasound, and computed tomography scan of the thorax and abdomen should thus be performed before initiation of therapy.

Ultrasonography in gastroenterology

Ultrasonography (US) is a safe and available real-time, high-resolution imaging method, which during the last decades has been increasingly integrated as a clinical tool in gastroenterology. New US applications have emerged with enforced data software and new technical solutions, including strain evaluation, three-dimensional imaging and use of ultrasound contrast agents. Specific gastroenterologic applications have been developed by combining US with other diagnostic or therapeutic methods, such as endoscopy, manometry, puncture needles, diathermy and stents. US provides detailed structural information about visceral organs without hazard to the patients and can play an important clinical role by reducing the need for invasive procedures. This paper presents different aspects of US in gastroenterology, with a special emphasis on the contribution from Nordic scientists in developing clinical applications.

Miniprobe endoscopic ultrasound accurately stages esophageal cancer and guides therapeutic decisions in the era of neoadjuvant therapy: results of a multicenter cohort analysis

BACKGROUND

Despite recent advances in imaging techniques, adequate classification of esophageal lesions is still challenging. Accurate staging of tumors of the esophagus is a precondition for targeted therapy. In this retrospective, multicenter study, we report the role of high-frequency endoscopic ultrasound (EUS) catheter probes in pretherapeutic staging of esophageal neoplasms and thus guiding treatment decisions.

METHODS

A total of 143 patients (mean age of 63.8 ± 10.7 years) with esophageal carcinoma were recruited from five German centers (Münster, Oldenburg, Hannover, Wiesbaden, and Lüneburg). Tumor type was adenocarcinoma in 112 (78 %) cases and squamous cell carcinoma in 31 (22 %). Tumor localization was as follows: proximal 3, mid esophagus 7, and distal third 133. Histological correlation either through EMR or surgery was available. In all patients, pretherapeutic uT and uN classifications were compared to pT/pN classification obtained from surgically (esophagectomy, n = 93) or endoscopically (EMR, n = 50) resected tissue.

RESULTS

Overall, accuracy of uT classification was 60 % and of uN classification was 74 %. Sensitivity, specificity, and accuracy rates for local tumor extension were as follows (%): T1: 68/97/83; T2: 39/84/75; T3: 72/81/79; T4: 13/97/93; T1/2: 73/81/75; T3/4: 78/82/81. Relating to positive lymph node detection, sensitivity and specificity were 76 and 71 %, respectively.

CONCLUSIONS

Miniprobe EUS is an established method for the staging of esophageal tumors. Our large multicenter cohort shows a solid accuracy of miniprobe EUS with respect to differentiating locally advanced from limited cancer and assisting to determine the treatment regimen in the era of neoadjuvant therapy; consequently, 78 % of patients would have been assigned to the adequate therapeutic regimen, whereas 11 % of patients would have been overtreated and 11 % undertreated.

Long-term survival from adenocarcinoma of the esophagus after transthoracic and transhiatal esophagectomy

BACKGROUND

The effects of transthoracic or transhiatal esophagectomy on the long-term survival of patients who had adenocarcinoma of the esophagus were compared, as were factors applicable in preoperative stratification of patient treatment.

METHODS

A cohort of 147 consecutive patients with adenocarcinoma of the esophagus was evaluated for esophagectomy between 1984 and 2000. The patients were followed prospectively and observed survival rates of patients with a transthoracic or transhiatal approach to esophagectomy were compared by standardized mortality ratio (SMR) and relative mortality ratio (RMR) using the expected survival of a matched Norwegian population.

RESULTS

A R0 resection was performed by transthoracic (n = 33) or a transhiatal (n = 55) esophagectomy in 88 (60%) patients with a median age of 61 (range: 35-77) and 70 (42-88) years, respectively (P <0.001). Tumor stages and other possible risk factors were similar in the two groups. Transthoracic or transhiatal esophagectomy resulted in a median survival time of 20.5 (95% confidence interval (CI): 10.4-57.6) and 16.4 (10.6-28.7) months, respectively. The respective survival rates were 31.2% and 27.8% by 5 years, and 21.3% and 16.6% by 10 years with an overall RMR of 1.14 (P = 0.63). Median survival time in the absence or presence of lymph node metastases was 74.0 (95% CI: 17.5-166.4) and 10.7 (7.9-14.9) months. The corresponding survival rates by 10 years with non-involved or involved nodes were 48.9% and 3.8% respectively (RMR 2.22, P = 0.007). Patients with a pT1-tumor were few and the survival rate was not very different from that of the general population (SMR = 1.7, 95% CI: 0.7-4.1). The median survival time of patients with a pT2-tumor was 30.4 (95% CI: 9.0-142) months and with a pT3-tumor 14 (9.2-16.4) months. The survival rates by 10 years among patients with a pT1 tumor were 57.0% (95% CI: 14.9-78.9), pT2 33.3% (11.8-52.2), and pT3 7.1% (1.9-15.5). The relative mortality for T3 stages compared to T1 stages was statistically significant (RMR = 3.22, P = 0.024).

CONCLUSION

Transthoracic and transhiatal esophagectomy are both effective approaches for treatment of adenocarcinoma of the esophagus and survival of more than 10 years can be expected without adjuvant chemotherapy. However, increasing depth of tumor invasion and lymph node metastases reduce life expectancy.

Advances in endoscopic diagnosis of early esophageal cancer

Esophageal cancer is one of the most common malignancies in China. The prognosis of esophageal carcinoma is closely related to the stage of the disease at the time of detection. Patients with early lesions have an excellent prognosis, whereas those with more advanced stages of the disease usually have a poor prognosis. Therefore, the early detection of these lesions is of the greatest importance for treatment. Recently, many endoscopic methods have been developed, such as fluorescence endoscopy, confocal endoscopy, optical coherence tomography (OCT), and electronic staining imaging technology which includes narrow band imaging (NBI), Fujinon intelligent chromoendoscopy (FICE) and I-Scan. However, the clinical value of these techniques needs to be ascertained in the coming years. This paper reviews the progress of endoscopic diagnosis of early esophageal cancer.

Role of endoscopic ultrasound in superficial esophageal cancer

The recent increase in the incidence of superficial esophageal cancer and promising developments in potentially curative endoscopic therapies have placed endoscopic ultrasound in a central position with regard to decision making. This is a review of the literature to determine the role of endoscopic ultrasound and high frequency probe ultrasonography in the assessment of superficial esophageal carcinomas.

Upper gastrointestinal tumors: current status and future perspectives

Recent therapeutic developments that have provided new promising and successful approaches to the treatment of solid tumors are in large part due to the increasing understanding of their molecular biology. Despite this progress, these new therapies have provided minimal benefit in the treatment of upper gastrointestinal (GI) malignancies. Hence, the overall survival of patients with upper GI tumors remains dismal. These disappointing results are largely due to the lack of early detection strategies, inadequate medical treatments and the poor understanding of upper GI tumor biology. Clinically, the treatment paradigm has been evolving for these malignancies. Esophageal cancer is now commonly treated with preoperative chemoradiation in the USA, in both academic and community cancer centers, due to its theoretical advantages. Adjuvant chemotherapy and chemoradiation are also frequently used in patients with pancreatic cancer. Exciting prospects remain in the medical and surgical treatment of these malignancies with the inclusion of biologic agents in many protocols, newer chemotherapeutic agents (such as S-1 in the treatment of gastric cancer), and the use of minimally invasive procedures for the treatment of premalignant and, possibly, early malignant lesions of the esophagus and stomach. This review focuses on the current practice in the management of upper GI tumors and summarizes the recent advances in the field.

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.

Endoscopic ultrasound with conventional probe and miniprobe in preoperative staging of esophageal cancer

BACKGROUND

Using an endoscopic ultrasound (EUS) miniprobe, even highly stenotic esophageal cancers precluding the passage of a conventional probe can be examined without prior dilatation.

OBJECTIVE

To assess: (1) staging accuracy of conventional EUS probe and miniprobe, (2) variables influencing staging accuracy, (3) endoscopic features predicting tumor stage.

METHODS

Ninety-seven consecutive patients with esophageal cancer undergoing complete surgical resection were included. Preoperative EUS was performed using a conventional probe in nonstenotic tumors and a miniprobe in stenotic tumors. Accuracy of EUS for T and N stages was compared to pathohistological staging.

RESULTS

Overall EUS staging accuracy was 73.2% for T stage and 74.2% for N stage. It was similar for the miniprobe used in stenotic tumors vs the conventional probe used in nonstenotic tumors. Based on EUS, 84.5% of the patients would have been assigned to the appropriate therapy protocol (primary surgery vs neoadjuvant therapy). Endoscopic tumor features had no influence on staging accuracy. Tumor length >5 cm predicted advanced T and nodal positive stages.

CONCLUSIONS

The miniprobe allows adequate EUS staging of stenotic esophageal tumors precluding the passage of a conventional probe. Therefore, dilatation therapy of stenotic cancers to conduct conventional EUS should be avoided.

Staging investigations for oesophageal cancer: a meta-analysis

The aim of the study was to compare the diagnostic performance of endoscopic ultrasonography (EUS), computed tomography (CT), and ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in staging of oesophageal cancer. PubMed was searched to identify English-language articles published before January 2006 and reporting on diagnostic performance of EUS, CT, and/or FDG-PET in oesophageal cancer patients. Articles were included if absolute numbers of true-positive, false-negative, false-positive, and true-negative test results were available or derivable for regional, celiac, and abdominal lymph node metastases and/or distant metastases. Sensitivities and specificities were pooled using a random effects model. Summary receiver operating characteristic analysis was performed to study potential effects of study and patient characteristics. Random effects pooled sensitivities of EUS, CT, and FDG-PET for regional lymph node metastases were 0.80 (95% confidence interval 0.75–0.84), 0.50 (0.41–0.60), and 0.57 (0.43–0.70), respectively, and specificities were 0.70 (0.65–0.75), 0.83 (0.77–0.89), and 0.85 (0.76–0.95), respectively. Diagnostic performance did not differ significantly across these tests. For detection of celiac lymph node metastases by EUS, sensitivity and specificity were 0.85 (0.72–0.99) and 0.96 (0.92–1.00), respectively. For abdominal lymph node metastases by CT, these values were 0.42 (0.29–0.54) and 0.93 (0.86–1.00), respectively. For distant metastases, sensitivity and specificity were 0.71 (0.62–0.79) and 0.93 (0.89–0.97) for FDG-PET and 0.52 (0.33–0.71) and 0.91 (0.86–0.96) for CT, respectively. Diagnostic performance of FDG-PET for distant metastases was significantly higher than that of CT, which was not significantly affected by study and patient characteristics. The results suggest that EUS, CT, and FDG-PET each play a distinctive role in the detection of metastases in oesophageal cancer patients. For the detection of regional lymph node metastases, EUS is most sensitive, whereas CT and FDG-PET are more specific tests. For the evaluation of distant metastases, FDG-PET has probably a higher sensitivity than CT. Its combined use could however be of clinical value, with FDG-PET detecting possible metastases and CT confirming or excluding their presence and precisely determining the location(s).

EUS staging of upper GI malignancies: results of a prospective randomized trial

BACKGROUND

Electronic 270 degrees transverse-array EUS (TA-EUS) provides high-quality cross-sectional images but cannot guide FNA. Linear EUS (L-EUS) provides longitudinal images of malignancies and the ability to guide FNA.

OBJECTIVE

We conducted a prospective randomized comparison of TA-EUS and L-EUS for the staging of upper-GI (UGI) malignancies.

DESIGN

Forty-three patients underwent L-EUS immediately followed by TA-EUS (N = 27, 63%) or TA-EUS immediately followed by L-EUS (N = 16, 37%).

PATIENTS

Forty-three subjects (mean age, 64 years; 37 men) with an UGI malignancy (4 stomach and 38 esophageal) were evaluated with both TA-EUS and L-EUS.

INTERVENTIONS

Abnormal lymph nodes were sampled by FNA for cytology.

RESULTS

There was agreement on the T stage by linear and radial techniques in 38 of 43 subjects (88%). Twenty-seven of 43 patients (63%) had abnormal lymph nodes by linear or transverse-array imaging. L-EUS demonstrated 66 abnormal lymph nodes in 27 subjects (average of 2.4 nodes/subject). TA-EUS demonstrated 90 abnormal lymph nodes in 27 subjects (average of 3.3 nodes/subject, P = .009, compared with L-EUS). In 16 of the 27 subjects, an FNA was performed, which was positive in 13 cases (81%) and negative in 3 cases (10%) for malignancy.

CONCLUSIONS

TA-EUS and L-EUS provide similar results of T staging of UGI malignancies. However, the number of abnormal lymph nodes detected by TA-EUS was more than by L-EUS. These findings suggest that radial or transverse-array EUS imaging should be the primary method for staging of UGI malignancies.

Role of endoscopic ultrasonography in the staging and follow-up of esophageal cancer

PURPOSE

To evaluate the role of endoscopic ultrasonography (EUS) in the initial staging and follow-up of esophageal cancer on the basis of a review of the published literature.

METHODS

Articles published from 1985 to 2005 were searched and reviewed using the following keywords: "esophageal cancer staging," "endoscopic ultrasound," and "endoscopic ultrasonography."

RESULTS

For initial anatomic staging, EUS results have consistently shown more than 80% accuracy compared with surgical pathology for depth of tumor invasion (T). Accuracy increased with higher stage, and was >90% for T3 cancer. EUS results have shown accuracy in the range of 75% for initial staging of regional lymph nodes (N). EUS has been invariably more accurate than computed tomography for T and N staging. EUS is limited for staging distant metastases (M), and therefore EUS is usually performed after a body imaging modality such as computed tomography or positron emission tomography. Pathologic staging can be achieved at EUS using fine-needle aspiration (FNA) to obtain cytology from suspect Ns. FNA has had greatest efficacy in confirming celiac axis lymph node metastases with more than 90% accuracy. EUS is inaccurate for staging after radiation and chemotherapy because of inability to distinguish inflammation and fibrosis from residual cancer, but a more than 50% decrease in tumor cross-sectional area or diameter has been found to correlate with treatment response.

CONCLUSION

EUS has a central role in the initial anatomic staging of esophageal cancer because of its high accuracy in determining the extent of locoregional disease. EUS is inaccurate for staging after radiation therapy and chemotherapy, but can be useful in assessing treatment response.

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.

Bronchoscopic ultrasonography in the diagnosis of tracheobronchial invasion of esophageal cancer

OBJECTIVE

To study the usefulness of bronchoscopic ultrasonography in diagnosing tracheobronchial invasion of esophageal cancer and to compare it with endoscopic ultrasonography, bronchoscopy, and computed tomography.

METHODS

We prospectively investigated 59 patients with newly diagnosed esophageal cancer located at or above the level of the tracheal bifurcation. A 20-MHz ultrasonic probe covered by a sheath with a balloon inflated with water was used for bronchoscopic ultrasonography. The presence of tracheobronchial invasion was diagnosed on the basis of an interruption in the most external hyperechoic layer of the tracheal bronchus.

RESULTS

Bronchoscopic ultrasonography was completed without complications in all patients, but endoscopic ultrasonography was performed completely in only 44% of them. The overall accuracy rates for diagnosis of tracheobronchial invasion on the basis of bronchoscopy, bronchoscopic ultrasonography, endoscopic ultrasonography, and computed tomography were 78%, 91%, 85%, and 58%, respectively. Statistical examination showed that the accuracy of bronchoscopic ultrasonography and bronchoscopy was significantly greater than that of computed tomography, and the accuracy of bronchoscopic ultrasonography was greater than that of bronchoscopy.

CONCLUSIONS

Bronchoscopic ultrasonography is useful for evaluating cancer invasion into the tracheal bronchus. It is more accurate than the other methods and could be used to visualize the layered structure of the tracheal bronchus in all patients.