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

Curriculum for diagnostic endoscopic ultrasound training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

The European Society of Gastrointestinal Endoscopy (ESGE) has recognized the need to formalize and enhance training in diagnostic endoscopic ultrasound (EUS). This manuscript represents the outcome of a formal Delphi process resulting in an official Position Statement of the ESGE and provides a framework to develop and maintain skills in diagnostic EUS. This curriculum is set out in terms of the prerequisites prior to training; the recommended steps of training to a defined syllabus; the quality of training; and how competence should be defined and evidenced before independent practice. 1:  Trainees should have achieved competence in upper gastrointestinal endoscopy before training in diagnostic EUS. 2:  The development of diagnostic EUS skills by methods that do not involve patients is advisable, but not mandatory, prior to commencing formal training in diagnostic EUS. 3:  A trainee's principal trainer should be performing adequate volumes of diagnostic EUSs to demonstrate maintenance of their own competence. 4:  Training centers for diagnostic EUS should offer expertise, as well as a high volume of procedures per year, to ensure an optimal level of quality for training. Under these conditions, training centers should be able to provide trainees with a sufficient wealth of experience in diagnostic EUS for at least 12 months. 5:  Trainees should engage in formal training and supplement this with a range of learning resources for diagnostic EUS, including EUS-guided fine-needle aspiration and biopsy (FNA/FNB). 6:  EUS training should follow a structured syllabus to guide the learning program. 7:  A minimum procedure volume should be offered to trainees during diagnostic EUS training to ensure that they have the opportunity to achieve competence in the technique. To evaluate competence in diagnostic EUS, trainees should have completed a minimum of 250 supervised EUS procedures: 80 for luminal tumors, 20 for subepithelial lesions, and 150 for pancreaticobiliary lesions. At least 75 EUS-FNA/FNBs should be performed, including mostly pancreaticobiliary lesions. 8:  Competence assessment in diagnostic EUS should take into consideration not only technical skills, but also cognitive and integrative skills. A reliable valid assessment tool should be used regularly during diagnostic EUS training to track the acquisition of competence and to support trainee feedback. 9:  A period of supervised practice should follow the start of independent activity. Supervision can be delivered either on site if other colleagues are already practicing EUS or by maintaining contacts with the training center and/or other EUS experts. 10:  Key performance measures including the annual number of procedures, frequency of obtaining a diagnostic sample during EUS-FNA/FNB, and adverse events should be recorded within an electronic documentation system and evaluated.

Comparison of diagnostic accuracy between linear EUS and miniprobe EUS for submucosal invasion in suspected early gastric cancer

OBJECTIVE

This study assessed the accuracy of linear endoscopic ultrasound (EUS) in diagnosing submucosal (SM) invasion and compared linear EUS with mini-probe EUS in suspected early gastric cancer (EGC) patients.

METHODS

Patients diagnosed with biopsy-verified suspected EGC were analysed retrospectively. They were all examined by linear EUS or miniprobe EUS for preoperative diagnosis of invasion depth and underwent endoscopic or surgical treatment for radical resection. The invasion depth evaluated by EUS and pathology were categorized into no invasion of SM and invasion of SM or deeper. We compared the diagnosis of EUS with postoperative pathology results.

RESULTS

A total of 105 patients were included in the final analysis. We found that the overall prediction accuracy of linear EUS (n = 57) for SM invasion in suspected EGC was higher than that of mini-probe EUS (n = 48), but no statistically significant differences were noted (82.5% vs 72.9%, p = 0.344). The negative predictive value (NPV) of linear EUS was significantly higher than that of mini-probe EUS (100% vs 82.8%, p = 0.037). The binary logistic regression analysis identified that tumor size (p = 0.036), the presence of ulceration (p < 0.001) and the EUS type (p = 0.027) were independent risk factors for the diagnosis of SM invasion by EUS. The area under the receiver operating curve (ROC) was 0.889 and 0.719 for linear and mini-probe EUS, respectively.

CONCLUSION

Linear EUS diagnosed suspected EGC for SM invasion with higher accuracy than mini-probe EUS. Additionally, large and ulcerative lesions may lead to overestimation.

Linear-array endoscopic ultrasound improves the accuracy of preoperative submucosal invasion prediction in suspected early gastric cancer compared with radial endoscopic ultrasound: A prospective cohort study

BACKGROUND AND AIM

There is a lack of literature comparing linear endoscopic ultrasound (EUS) and radial EUS for the prediction of the depth of invasion in early gastric cancer (EGC). The aim of this study is to evaluate the accuracy of linear EUS for the diagnosis of submucosal (SM) invasion and compare linear EUS with radial EUS in suspected EGC patients.

METHODS

Seventy-two consecutive patients with suspected EGC who underwent a preoperative assessment using linear EUS or radial EUS were prospectively enrolled. The depth of invasion was categorized into mucosal to SM (< T1b) and SM or deeper (≥ T1b), and the EUS-determined diagnosis was compared with postoperative histopathological findings.

RESULTS

Thirty-nine patients underwent radial EUS, and 33 patients underwent linear EUS examination. The baseline characteristics between the groups were well balanced. The diagnostic accuracy was much higher for patients who underwent linear EUS compared with radial EUS (90.9% vs 69.2%, P = 0.024). The sensitivity was 92.3% (95% confidence interval [CI] 66.7-98.6%) for linear EUS and 90.9% (95% CI 62.3-98.4%) for radial EUS. The specificity was 90.0% (95% CI 69.9-97.2%) in the linear EUS group, while the specificity was 60.7% (95% CI 42.4-76.4%) in the radial EUS group. Univariate analysis showed that EUS type (odds ratio 0.225, 95% CI 0.057-0.884, P = 0.033) was an associated risk factor of incorrect T1b staging in EGC patients. The area under the receiver operating curve was 0.912 and 0.758 for linear and radial EUS, respectively.

CONCLUSION

Linear EUS was more accurate for determining SM invasion and therapeutic strategy in suspected EGC patients compared with radial EUS.

What should be known prior to performing EUS exams? (Part II)

In “What should be known prior to performing EUS exams, Part I,” the authors discussed the need for clinical information and whether other imaging modalities are required before embarking EUS examinations. Herewith, we present part II which addresses some (technical) controversies how EUS is performed and discuss from different points of view providing the relevant evidence as available. (1) Does equipment design influence the complication rate? (2) Should we have a standardized screen orientation? (3) Radial EUS versus longitudinal (linear) EUS. (4) Should we search for incidental findings using EUS?

Endoscopic ultrasonography is not required for staging malignant esophageal strictures that preclude the passage of a diagnostic gastroscope

BACKGROUND AND AIM

Endoscopic ultrasound (EUS) is considered the most sensitive modality for local staging of esophageal cancer (ECA) and current guidelines recommend EUS in all patients with non-metastatic disease. Our aim was to identify a subset of patients with stenotic, non-metastatic ECA who will not benefit from staging EUS.

METHODS

This multicenter study evaluated consecutive patients with newly diagnosed non-metastatic ECA referred for local staging by EUS. All patients had endoscopic evaluation of malignant strictures with 9.8/9.9-mm diagnostic gastroscope prior to EUS. Main outcome measure was to evaluate the relationship between degree of malignant stenosis and tumor staging by EUS.

RESULTS

Of 100 patients (median age, 65 years; male 81%), gastroscope could not be advanced past the stricture in 46, all of whom (100%) had locally advanced disease at EUS: T3N0/N+ in 39 and T4N0/N+ in seven. Echoendoscope could not traverse the stricture in any of these patients. Gastroscope could be advanced through the stricture in 54 patients in whom EUS staging was T1N0 in five, T2N0/N+ in eight and T3N0/N+ in 41; echoendoscope could not pass through the stricture in 24 of these 54 (44.4%) patients, all of whom had T3N0/N+ disease. On logistic regression analysis, inability to pass a gastroscope through the stricture was significantly associated with advanced (T3/4) tumor stage (OR = 28.7, 95% CI = 1.64-501.2; P = 0.021).

CONCLUSION

Routine EUS examination may not be required in all patients with ECA as the inability to advance a diagnostic gastroscope past a malignant stricture correlates 100% with locally advanced disease on EUS.

Linear-array EUS improves detection of pancreatic lesions in high-risk individuals: a randomized tandem study

BACKGROUND

Studies comparing linear and radial EUS for the detection of pancreatic lesions in an asymptomatic population with increased risk for pancreatic cancer are lacking.

OBJECTIVES

To compare pancreatic lesion detection rates between radial and linear EUS and to determine the incremental diagnostic yield of a second EUS examination.

DESIGN

Randomized controlled tandem study.

SETTING

Five academic centers in the United States.

PATIENTS

Asymptomatic high-risk individuals (HRIs) for pancreatic cancer undergoing screening EUS.

INTERVENTIONS

Linear and radial EUS performed in randomized order.

MAIN OUTCOME MEASUREMENTS

Pancreatic lesion detection rate by type of EUS, miss rate of 1 EUS examination, and incremental diagnostic yield of a second EUS examination (second-pass effect).

RESULTS

Two hundred seventy-eight HRIs were enrolled, mean age 56 years (43.2%), and 90% were familial pancreatic cancer relatives. Two hundred twenty-four HRIs underwent tandem radial and linear EUS. When we used per-patient analysis, the overall prevalence of any pancreatic lesion was 45%. Overall, 16 of 224 HRIs (7.1%) had lesions missed during the initial EUS that were detected by the second EUS examination. The per-patient lesion miss rate was significantly greater for radial followed by linear EUS (9.8%) than for linear followed by radial EUS (4.5%) (P = .03). When we used per-lesion analysis, 73 of 109 lesions (67%) were detected by radial EUS and 99 of 120 lesions (82%) were detected by linear EUS (P < .001) during the first examination. The overall miss rate for a pancreatic lesion after 1 EUS examination was 47 of 229 (25%). The miss rate was significantly lower for linear EUS compared with radial EUS (17.5% vs 33.0%, P = .007).

LIMITATIONS

Most detected pancreatic lesions were not confirmed by pathology.

CONCLUSION

Linear EUS detects more pancreatic lesions than radial EUS. There was a "second-pass effect" with additional lesions detected with a second EUS examination. This effect was significantly greater when linear EUS was used after an initial radial EUS examination.

Diagnostic accuracy of endoscopic ultrasonography (EUS) for the preoperative locoregional staging of primary gastric cancer

BACKGROUND

Endoscopic ultrasound (EUS) is proposed as an accurate diagnostic device for the locoregional staging of gastric cancer, which is crucial to developing a correct therapeutic strategy and ultimately to providing patients with the best chance of cure. However, despite a number of studies addressing this issue, there is no consensus on the role of EUS in routine clinical practice.

OBJECTIVES

To provide both a comprehensive overview and a quantitative analysis of the published data regarding the ability of EUS to preoperatively define the locoregional disease spread (i.e., primary tumor depth (T-stage) and regional lymph node status (N-stage)) in people with primary gastric carcinoma.

SEARCH METHODS

We performed a systematic search to identify articles that examined the diagnostic accuracy of EUS (the index test) in the evaluation of primary gastric cancer depth of invasion (T-stage, according to the AJCC/UICC TNM staging system categories T1, T2, T3 and T4) and regional lymph node status (N-stage, disease-free (N0) versus metastatic (N+)) using histopathology as the reference standard. To this end, we searched the following databases: the Cochrane Library (the Cochrane Central Register of Controlled Trials (CENTRAL)), MEDLINE, EMBASE, NIHR Prospero Register, MEDION, Aggressive Research Intelligence Facility (ARIF), ClinicalTrials.gov, Current Controlled Trials MetaRegister, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), from 1988 to January 2015.

SELECTION CRITERIA

We included studies that met the following main inclusion criteria: 1) a minimum sample size of 10 patients with histologically-proven primary carcinoma of the stomach (target condition); 2) comparison of EUS (index test) with pathology evaluation (reference standard) in terms of primary tumor (T-stage) and regional lymph nodes (N-stage). We excluded reports with possible overlap with the selected studies.

DATA COLLECTION AND ANALYSIS

For each study, two review authors extracted a standard set of data, using a dedicated data extraction form. We assessed data quality using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. We performed diagnostic accuracy meta-analysis using the hierarchical bivariate method.

MAIN RESULTS

We identified 66 articles (published between 1988 and 2012) that were eligible according to the inclusion criteria. We collected the data on 7747 patients with gastric cancer who were staged with EUS. Overall the quality of the included studies was good: in particular, only five studies presented a high risk of index test interpretation bias and two studies presented a high risk of selection bias.For primary tumor (T) stage, results were stratified according to the depth of invasion of the gastric wall. The meta-analysis of 50 studies (n = 4397) showed that the summary sensitivity and specificity of EUS in discriminating T1 to T2 (superficial) versus T3 to T4 (advanced) gastric carcinomas were 0.86 (95% confidence interval (CI) 0.81 to 0.90) and 0.90 (95% CI 0.87 to 0.93) respectively. For the diagnostic capacity of EUS to distinguish T1 (early gastric cancer, EGC) versus T2 (muscle-infiltrating) tumors, the meta-analysis of 46 studies (n = 2742) showed that the summary sensitivity and specificity were 0.85 (95% CI 0.78 to 0.91) and 0.90 (95% CI 0.85 to 0.93) respectively. When we addressed the capacity of EUS to distinguish between T1a (mucosal) versus T1b (submucosal) cancers the meta-analysis of 20 studies (n = 3321) showed that the summary sensitivity and specificity were 0.87 (95% CI 0.81 to 0.92) and 0.75 (95% CI 0.62 to 0.84) respectively. Finally, for the metastatic involvement of lymph nodes (N-stage), the meta-analysis of 44 studies (n = 3573) showed that the summary sensitivity and specificity were 0.83 (95% CI 0.79 to 0.87) and 0.67 (95% CI 0.61 to 0.72), respectively.Overall, as demonstrated also by the Bayesian nomograms, which enable readers to calculate post-test probabilities for any target condition prevalence, the EUS accuracy can be considered clinically useful to guide physicians in the locoregional staging of people with gastric cancer. However, it should be noted that between-study heterogeneity was not negligible: unfortunately, we could not identify any consistent source of the observed heterogeneity. Therefore, all accuracy measures reported in the present work and summarizing the available evidence should be interpreted cautiously. Moreover, we must emphasize that the analysis of positive and negative likelihood values revealed that EUS diagnostic performance cannot be considered optimal either for disease confirmation or for exclusion, especially for the ability of EUS to distinguish T1a (mucosal) versus T1b (submucosal) cancers and positive versus negative lymph node status.

AUTHORS' CONCLUSIONS

By analyzing the data from the largest series ever considered, we found that the diagnostic accuracy of EUS might be considered clinically useful to guide physicians in the locoregional staging of people with gastric carcinoma. However, the heterogeneity of the results warrants special caution, as well as further investigation for the identification of factors influencing the outcome of this diagnostic tool. Moreover, physicians should be warned that EUS performance is lower in diagnosing superficial tumors (T1a versus T1b) and lymph node status (positive versus negative). Overall, we observed large heterogeneity and its source needs to be understood before any definitive conclusion can be drawn about the use of EUS can be proposed in routine clinical settings.

Multicenter randomized controlled trial comparing the performance of 22 gauge versus 25 gauge EUS-FNA needles in solid masses

BACKGROUND AND AIMS

Few randomized studies have assessed the clinical performance of 25-gauge (25G) needles compared with 22-gauge (22G) needles during endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy of intra-abdominal lesions. We aimed to compare the diagnostic yield, as well as performance characteristics of 22G versus 25G EUS biopsy needles by determining their diagnostic capabilities, the number of needle passes as well as cellularity of aspirated tissue specimen.

METHODS

The study is a prospective, randomized, multicenter study. Patients were referred between January 2009 and January 2010 for diagnostic EUS including EUS-guided FNA of different lesions adjacent to the upper GI tract. All patients were randomized to EUS-FNA performed with either a 22G or 25G aspiration needle.

RESULTS

EUS-FNA was performed in 135 patients (62 patients with a 22G needle). Sensitivity and specificity of the 22G needle was 94.1% and 95.8%, respectively, and for the 25G needle 94.1% and 100%, respectively. Investigators reported better visualization and performance for the 22G needle compared to the 25G (p < 0.0001). The number of tissue slides obtained was higher for the 22G needle during the second and third needle passes (p < 0.05). We did not observe significant differences between the number and preservation status of obtained cells (p > 0.05).

CONCLUSIONS

A significant difference was found between the two types of needles in terms of reduced visualization of the 25G needle and suboptimal performance rating. However, this did not impact on overall results since both needles were equally successful in terms of a high diagnostic yield and overall accuracy.

A comparison of electronic radial and curvilinear endoscopic ultrasonography in the detection of pancreatic malignant tumor

OBJECTIVE

There is no comparative study of electronic radial endoscopic ultrasonography (ER-EUS) and electronic curvilinear EUS (EC-EUS). The aim of this study was to compare the accuracy of ER-EUS and EC-EUS for detecting pancreatic malignancies.

METHODS

This was a retrospective review of the patients who had EUS assessment from September 2008 to December 2011 for suspicious pancreatic tumors. Sensitivity, specificity, and area under the ROC curve to detect pancreatic malignancies were calculated and compared between the ER-EUS and EC-EUS cohort. The final diagnosis of pancreatic malignancy was based on pathology, or the consensus of patient's clinical course and multimodal imaging tests.

RESULTS

Two hundred twenty-one patients were included and divided into two cohorts: ER-EUS (n = 139) and EC-EUS (n = 82) cohorts. With propensity score matching method, 70 cases in each cohort were selected for the comparison. There was no significant difference in sensitivity, specificity, and area under the ROC curve to detect pancreatic malignancy between ER-EUS and EC-EUS cohort (88.5 vs. 100%, 88.6 vs. 90.9%, 0.8855 vs. 0.9545).

CONCLUSION

ER-EUS and EC-EUS provided similar accuracy for the detection of pancreatic malignancies. In view of similar diagnostic results of ER-EUS and EC-EUS for the detection of pancreatic malignancy, and the advantage of being able to perform FNA with EC-EUS, EC-EUS may be the preferred choice.

Randomized clinical trials in esophageal carcinoma

The treatment of esophageal cancer with curative intent remains highly controversial, with advocates of surgery alone, chemoradiotherapy alone, surgery with adjuvant therapy (including neoadjuvant and postoperative), and trimodality therapy each contributing prospective randomized controlled trials (PRCTs) to the body of scientific publications between 2000 and 2008. Any improvements in survival have been small in absolute percentage terms, and as such PRCTs published over the last decade have met the same primary obstacle encountered by the studies from the two prior decades, namely lack of power to detect small differences in outcome. Variations in staging methods, surgical technique, radiotherapy technique, and chemotherapy regime have in turn been the subject of PRCTs over the last nine years. In many cases primary end points have not been survival but rather rates of complication or response. As well as giving an overview of PRCTs, this article collates the level Ia evidence published to date.

Endosonographic staging of upper intestinal malignancy

Numerous studies conducted over the last 25 years provide evidence on the high diagnostic accuracy and important role of endoscopic ultrasonography (EUS) in staging oesophageal and gastric carcinoma. This extensive research was recently subjected to metaanalyses, condensing our knowledge on EUS performance and facilitating its comparison with competing methods. It is, however, important to realise that the management of oesophageal and gastric carcinoma is evolving and so are staging algorithms, setting new challenges for EUS and re-defining its position. Restaging after neoadjuvant treatment and precise assessment of early carcinoma before endoscopic treatment are areas of growing interest, but the role of EUS in these settings is rather limited. Rapidly developing cross-sectional imaging has the potential to challenge the position of EUS as the most accurate method in loco-regional staging. On the other hand, EUS guided fine-needle aspiration offers the unique opportunity to obtain cytological confirmation of lymph node metastases, with future potential for molecular staging.

Prospective, randomized comparison of mechanical and electronic radial endoscopic ultrasound systems: assessment of performance parameters and image quality

OBJECTIVE

Implementation of electronic image technology in endoscopic ultrasonography (EUS) should improve image quality, but systematic data are scarce. The purpose of this study was to compare the image quality and performance of an electronic and a mechanical radial echoendoscope.

MATERIAL AND METHODS

Eighty consecutive patients (42 M, mean age 56 years) in a tertiary referral center, without gross pathology (advanced tumors excluded), were prospectively randomized to EUS with the mechanical or electronic echoendoscope. Images from five standardized positions (pancreatobiliary and upper gastrointestinal (GI) tract) were taken by two examiners of differing experience. Time to acquire images was noted. Penetration depth was also measured. Image quality variables (overall quality, contrast, and structure discrimination) were assessed blindly on the basis of randomly shuffled images during three independent evaluations by the same experienced examiner (mean values were taken), using a visual analogue scale (VAS) from 1 (excellent) to 10 (inadequate).

RESULTS

Time needed to achieve visualization of the distal common bile duct (CBD) was significantly shorter with the electronic scope (49.7+/-8.6 versus 97.4+/-8.5 s; p<0.001). Image quality with the electronic scope was rated significantly better for all variables assessed, whereas EUS penetration depth was similar in both groups. There were no differences in examiner experience.

CONCLUSIONS

Electronic EUS provided better quality images according to the examiner's subjective assessment. An objective advantage was faster identification of the distal CBD.

The patient with unexplained elevated serum liver enzymes

The pattern of elevated serum liver enzymes in symptomatic or asymptomatic patients allows for an initial classification of liver diseases into cholestatic or hepatocellular diseases. A female patient with extrahepatic cholestasis due to segmental bile duct strictures and a localized mass lesion within the pancreas is presented. Although many diagnostic procedures were performed in this case the diagnosis was not obtained before surgical laparotomy was initiated with bioptic sampling from bile ducts, lymph nodes and pancreatic tissue. Microscopic examination of the specimen revealed extensive biliary and pancreatic scarring together with periductal infiltrates composed of lymphocytes and plasma cells consistent with sclerosing cholangitis in systemic autoimmune pancreatitis. The patient completely recovered upon treatment with prednisone and azathioprine. The difficult approach to the final diagnosis is discussed in light of established and modern diagnostic tools.