A comparison of the accuracy of echo features during endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration for diagnosis of malignant lymph node invasion

Preoperative staging of rectal cancer using a 7.5 MHz front-loading US probe

BACKGROUND

Conventional echoendoscopes have disadvantages when used for staging colorectal cancer including the inability to pass the instrument through tight stenosis and limited maneuverability. This study evaluated the preoperative use of a newly developed 7.5 MHz front-loading ultrasound probe (FLUP) for local staging of rectal cancer.

METHODS

A 7.5 MHz FLUP, diameter 7.3 mm, was used in this study. The mechanical shaft portion of the probe can be passed in retrograde fashion through the accessory channel of a standard colonoscope. Thirty-nine patients with rectal cancer underwent ultrasonography with this probe. The tumors were staged using the TNM system, and the results were compared with the histologic findings of the resected specimens.

RESULTS

The FLUP proved to be satisfactory, with respect to maneuverability, for traversing stenosis and accurate recognition of small tumors under direct endoscopic control. The accuracy of the FLUP for T staging was 82% (32 of 39) for all tumors, 90% in pT1, and 79% in pT2 to pT4 tumors. The accuracy of the FLUP for N staging was 72% (23 of 32) overall. The sensitivity was 83%, the specificity was 65%, the positive predictive value was 59%, and the negative predictive value was 87%.

CONCLUSIONS

The 7.5 MHz FLUP appears to be useful for preoperative local staging of rectal cancer. This system makes it technically easier to image small cancers as well as advanced rectal cancers.

Improved model for teaching interventional EUS

BACKGROUND

A swine model was previously developed for teaching endoscopic ultrasound (EUS). The purpose of this study was to improve this model and develop a method for creating focal lesions for EUS imaging and intervention.

METHODS

Experiments were performed in farm pigs (Sus scrofa) under general anesthesia. Under real-time EUS guidance attempts were made to create a submucosal lesion and a focal mediastinal lesion, to perform EUS-guided fine-needle aspiration of the pancreas, and to confirm the site of injection during "sham" EUS-guided celiac block.

RESULTS

A hypoechoic, submucosal mass was created in the stomach, which was then imaged by EUS and punctured trans-gastrically. Injection of saline solution in the mediastinum created a pseudo-mediastinal lymph node. A needle was then advanced trans-esophageally into the mediastinum to mimic EUS-guided fine-needle aspiration of a mediastinal lymph node. Abdominal exploration of the pigs after euthanasia confirmed injection of the sham celiac block around the celiac ganglion.

CONCLUSION

The swine model is not only useful for teaching normal EUS anatomy, but it may be a useful model for teaching EUS-guided intervention.

Thoracoscopic and laparoscopic staging for esophageal cancer

Accurate pretreatment staging for patients with esophageal cancer (EC) is becoming increasingly important in the evaluation and comparison of different treatment modalities. Noninvasive staging methods are imperfect in detecting lymph node metastasis in patients with EC. Surgical staging with the thoracoscopic/laparoscopic (Ts/Ls) technique may provide accurate staging information that is useful for evaluating and comparing the results of clinical trials of preoperative chemotherapy and radiotherapy. It can be used to confirm or exclude suspicious distant metastasis found by other staging methods. Pretreatment (lymph node) biopsies obtained by Ts/Ls staging allow further molecular biologic analysis to detect occult lymph node metastasis for more accurate lymph node staging. Since 1992, we have used Ts/Ls staging for EC in 111 patients. We found that Ts/Ls is a promising method for staging lymph nodes in EC patients. A recent study showed that pretreatment surgical lymph node staging can predict response and survival for EC patients receiving trimodality treatment (ie, radiation, chemotherapy, and surgery). The information obtained with surgical staging now offers us the opportunity to optimize therapy to specific patient groups based on the extent of disease at the time of initial presentation. Nevertheless, unlike the practice of mediastinoscopy in lung cancer patients, Ts/Ls staging in EC patients remains an academic interest rather than a clinical practice. The concept of accurate pretreatment staging of EC remains to be realized and accepted in the clinical community.

Defining a role for endoscopic ultrasound in staging periampullary tumors

BACKGROUND

The goal of the preoperative workup in patients with suspected periampullary carcinoma is to establish the diagnosis with a high degree of certainty. In this study we compared endoscopic ultrasonography (EUS) and computed tomography (CT) scans for the detection of tumor, lymph node metastasis, and vascular invasion in patients with suspected periampullary carcinoma in order to define a role for EUS in the preoperative staging of these patients.

METHODS

Thirty-seven consecutive patients received EUS and CT scanning followed by operation for presumed periampullary carcinoma during a 30-month period. Both imaging modalities were reviewed in a blinded fashion and the results compared with pathology and operative reports on all patients.

RESULTS

Sensitivity, specificity, positive predictive value, and negative predictive value for tumor detection by EUS were 97%, 33%, 94%, and 50%, respectively, compared with 82%, 66%, 97%, and 25% for CT scan. For lymph nodes the values were 21%, 80%, 57%, and 44%, respectively, for EUS compared with 42%, 73%, 67%, and 50% for CT. For vascular invasion, the values were 20%, 100%, 100%, and 89%, respectively, for EUS, compared with 80%, 87%, 44%, and 96% for CT.

CONCLUSIONS

CT is the initial study of choice in patients with suspected periampullary tumors. EUS is superior for detecting tumor and for predicting vascular invasion. Therefore, EUS should be used for patients in whom CT does not detect a mass and for those with an identifiable mass on CT in whom vascular invasion cannot be ruled out.

Use of minimally invasive surgery in staging esophageal cancer

Noninvasive staging of esophageal cancer (EC) is often inaccurate, and this fact has compromised clinical trials of treatment for EC. Prognostic evaluation might allocate chemotherapy and radiation more appropriately. Thoracoscopy and laparoscopy has recently shown promising results, and molecular analysis of the recovered tissue may further improve staging accuracy.

Diagnosis and staging of lung cancer

Lung cancer is the biggest cancer killer among men and women in the United States. Lung cancer can present in a myriad of ways and the goal of prompt diagnosis and staging requires that the clinician be able to knowledgeably choose from a variety of tools available for such purpose. Review of some of these tools and general strategies with regard to staging is provided. Many new technologies are becoming available and much evaluation needs to be done before their proper roles become well defined. Little has changed with regard to staging of small cell lung cancer in recent years. The International System for Staging Non-Small-Cell Lung Cancer was revised for a second time in 1997. Although the revisions have largely corrected the shortcomings of the 1985 version, some controversies persist. Whenever possible, a multidisciplinary approach to diagnosis, staging, and therapy should be utilized. This should include incorporating the services of the pulmonologist, the thoracic surgeon, the medical oncologist, the radiologist, the radiation therapist, the pathologist, the respiratory therapist, and the social worker.

Dilation of malignant esophageal stenosis to allow EUS guided fine-needle aspiration: safety and effect on patient management

BACKGROUND

Endoscopic ultrasonography (EUS) with fine-needle aspiration identifies patients with esophageal cancer who are unlikely to be cured by surgery. In approximately 30% of patients the staging procedure cannot be completed without dilation of an obstructing tumor.

METHODS

All EUS examinations for esophageal cancer requiring dilation from July 1995 to December 1998 were included. Yield was defined as newly diagnosed metastatic (celiac lymph nodes) or locally invasive disease that could not have been detected without dilation.

RESULTS

EUS was performed in 132 patients. Forty-two (32%) required 44 dilations. No complications occurred. Of the 42 patients with obstruction, 18 (43%) had celiac adenopathy of which 7 had malignant cells confirmed histologically, 3 had benign adenopathy, and 8 did not undergo fine-needle aspiration due to T4 stage disease (5) or intervening vessels (3). Two patients were upstaged after successful dilation from T2 N1 Mx to T4 N1 Mx and from T3 Nx Mx to T3 N1 M1. Overall, dilation allowed detection of advanced disease in 8 of 42 (19%) patients. Dilation to 11 to 12.8 mm was insufficient (36% success rate) to complete EUS compared with dilation to 14 to 16 mm (87%, p < 0.01).

CONCLUSION

Dilation of obstructing esophageal tumors allows identification of a large number of patients with advanced stage malignancy. Dilation to 14 to 16 mm is sufficient for complete staging in almost all patients.

Role of transesophageal endosonography-guided fine-needle aspiration in the diagnosis of lung cancer

STUDY OBJECTIVE

Bronchoscopic methods fail to diagnose lung cancer in up to 30% of patients. We studied the role of transesophageal endosonography (EUS)-guided fine-needle aspiration (FNA; EUS-FNA) in such patients.

DESIGN

Prospective study. The final diagnosis was confirmed by cytology, histology, or clinical follow-up.

SETTING

University hospital.

PATIENTS

Thirty-five patients (30 male and 5 female; mean age, 60.9 years; range, 34 to 88 years) with suspected lung cancer in whom bronchoscopic methods failed. Patients with a known diagnosis, recurrence of lung cancer, or mediastinal metastasis from an extrathoracic primary were excluded.

INTERVENTIONS

EUS and guided FNA of mediastinal lymph nodes.

RESULTS

The procedure was uneventful, and material was adequate in all. The final diagnosis by EUS-FNA was malignancy in 25 patients (11 adenocarcinoma, 10 small cell, 3 squamous cell, and 1 lymphoma) and benign disease in 9 patients (5 inflammatory, 2 sarcoidosis, and 2 anthracosis). Another patient with a benign result had signet-ring cell carcinoma diagnosed on pleural fluid cytology (probably false-negative in EUS-FNA). The sensitivity, specificity, accuracy, and positive and negative predictive values were 96, 100, 97, 100, and 90%, respectively. There were no complications. Reviewing the EUS morphology, the nodes were predominantly located in levels 7 and 8 of American Thoracic Society mediastinal lymph node mapping (subcarinal and paraesophageal region). In seven patients, the punctured nodes were < 1 cm (four malignant and three benign), which are difficult to sample by other methods. The malignant nodes had a hypoechoic, homogenous echotexture.

CONCLUSIONS

EUS-FNA is a safe, reliable, and accurate method to establish the diagnosis of suspected lung cancer when bronchoscopic methods fail, especially in the presence of small nodes.

Factors predicting the number of EUS-guided fine-needle passes for diagnosis of pancreatic malignancies

BACKGROUND

The factors that affect the number of needle passes needed to diagnose pancreatic malignancies using endoscopic ultrasound (EUS) -guided fine-needle aspiration are unknown.

METHODS

Patient and endosonographic data were prospectively recorded on 121 consecutive patients with pancreatic malignancy. Of these, 110 underwent EUS-guided fine-needle aspiration. A cytopathologist was in attendance for all aspiration procedures.

RESULTS

Initial EUS detected a pancreatic mass in 96% of cases; 23% of these were not seen by computed tomography. EUS-guided fine-needle aspiration was performed in 109 of 110 (99%) patients, including 95 masses, 7 lymph nodes, and 7 hepatic metastases. EUS-guided fine-needle aspiration provided a cytologic diagnosis of malignancy in 104 of 110 (95%). Only tumor differentiation and the site of aspiration affected the number of passes.

CONCLUSIONS

With the participation of a cytopathologist, EUS-guided fine-needle aspiration can diagnose pancreatic malignancies with a high degree of accuracy. Only the aspiration site (mass versus node/liver metastasis) can be used to direct the number of passes if a cytopathologist is not present. Without a cytopathologist in attendance, 5 to 6 passes should be made for pancreatic masses and 2 to 3 for liver metastases or lymph nodes; however, this approach will be associated with a 10% to 15% reduction in definitive cytologic diagnoses, extra procedure time, increased risk and additional needles.

Endoscopic ultrasonography in patients with gastro-esophageal cancer

For patients with gastro-esophageal cancer ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumor infiltration and local lymph nodes status. EUS is especially important in the preoperative staging of patients with esophageal cancer and patients with proximal gastric cancer. Here it allows for the identification of those patients with advanced disease who are unlikely to benefit from surgery and in whom a conservative palliative treatment is indicated. In advanced gastric cancer the clinical implications of EUS less clear. Still preoperative EUS is indicated in every patient with cancer of the proximal stomach to assess tumor infiltration in the esophagus. Relatively new is the use of EUS in staging early cancers in order to select patients for local endoscopic treatment. High-frequency miniprobes are the instruments of choice for imaging these lesions. Strict criteria should be applied in the selection of patients for local endoscopic treatment of early gastro-esophageal cancers. EUS guided fine needle aspiration (EUS-FNA) is currently only indicated in patients with esophageal cancer and suspicious celiac lymph nodes. It may become more important if new treatment protocols demand more objective and reliable assessment of lymph node status.

Diagnosis of the depth of invasion of gallbladder carcinoma by EUS

BACKGROUND

The prognosis of gallbladder carcinoma is dismal and relates to the depth of invasion as expressed by the T factor in TNM staging. We evaluated the utility of endoscopic ultrasound (EUS) in the diagnosis of the depth of invasion of gallbladder cancer.

METHODS

Thirty-nine patients who underwent both EUS and surgery were included in this study. The EUS images were classified according to the relation between tumor echo pattern and gallbladder-wall structure, and the resulting types were compared with depth of invasion as determined histologically. Based on the results, a set of diagnostic criteria is proposed.

RESULTS

The EUS images were classified into four categories. Type A is a pedunculated mass with a fine-nodular surface and intact neighboring wall. Type B is a broad-based mass with an irregular surface and intact outer hyperechoic layer of the adjacent wall. In type C, the outer hyperechoic layer is irregular due to a mass echo, whereas, in type D, the outer hyperechoic layer is disrupted by a mass echo. Each of the four categories of EUS images correlated well with the histologic depth of invasion.

CONCLUSION

EUS is useful in the T staging of gallbladder cancer.

Evaluation of metastatic celiac axis lymph nodes in patients with esophageal carcinoma: accuracy of EUS

BACKGROUND

Endosonography (EUS) is the most accurate modality for assessing depth of tumor invasion and local lymph node metastasis. However, its accuracy in the identification of metastatic (celiac axis) lymph nodes is less well defined. Our objective in this study was to determine the accuracy of Eus in detecting celiac axis lymph node metastasis in patients with esophageal carcinoma.

METHODS

Two hundred fourteen patients with esophageal carcinoma underwent preoperative EUS. Of these, 145 underwent attempted surgical resection and staging, and 4 underwent EUS-guided fine-needle aspiration of mediastinal and celiac lymph nodes. Local (mediastinal) and distant (celiac axis) lymph nodes were assessed for malignancy on the basis of four criteria (larger than 1 cm, round, homogeneous echo pattern, sharp borders). Accuracy of EUS was determined by means of correlating histopathologic findings for the resected lymph nodes or results of EUS-guided fine-needle aspiration cytologic examination.

RESULTS

Surgical exploration (n = 145) and fine-needle aspiration cytologic examination (n = 4) revealed metastatic celiac axis lymph nodes in 23 and metastatic mediastinal (local) lymph nodes in 93 of 149 patients with esophageal carcinoma. According to defined criteria for malignant lymph nodes, there were 19 true-positive and 4 falsenegative results. Sensitivity for the diagnosis of celiac lymph node metastasis with EUS was 83% with a 98% specificity. For the diagnosis of mediastinal lymph node metastasis, sensitivity was 79% and specificity was 63%. All patients with malignant celiac axis lymph nodes had local T3 (tumor breaching adventitia) or T4 (tumor invading adjacent organs) disease.

CONCLUSION

EUS is an excellent modality in the evaluation of metastatic celiac axis lymph nodes in patients with esophageal carcinoma. These findings should be used in selecting options for treatment. Sensitivity for detecting malignancy is consistent with that of prior studies, and local and regional lymph nodes and specificity is significantly higher.

Endoluminal ultrasonography for pancreatic diseases

Endoluminal ultrasonography was performed on 146 patients with pancreatobiliary diseases by using high-frequency, thin ultrasonic probes, and the usefulness of the new technique in diagnosis of pancreatic diseases was reported. The ultrasound probe could be inserted into the main pancreatic duct in 43 of 46 patients (93.5%), and images of the lesions could be obtained in 42 patients (91.3%). Endoluminal ultrasonography revealed a hypoechoic mass with clear margins and central echogenicity in patients with pancreatic carcinoma. Endoluminal ultrasonography showed normal pancreatic parenchyma as a fine reticular pattern and did not reveal the tumors surrounding the stenosis in patients with focal pancreatitis. Endoluminal ultrasonography in patients with intraductal papillary adenocarcinoma of the pancreas revealed cystic lesions with mural nodules more than 4 mm, mucus echoes, and solid tumors with mixed echo patterns. There were no severe complications, and acute pancreatitis occurred in none of 46 patients, but high-level serum amylase after examination occurred in 5 patients (10.9%). Endoluminal ultrasonography is useful for differential diagnosis in patients with small pancreatic tumors or cystic lesions, especially intraductal papillary tumors of the pancreas. Endoluminal ultrasonography is recommended as a precise examination for the diagnosis of cystic lesions of the pancreas or stenosis of the main pancreatic duct after ERCP and EUS.

Endoscopic ultrasound in pancreatic diseases. Indications, limitations, and the future

Endoscopic ultrasonography (EUS) is a significant advance in the diagnosis and management of pancreatic disease. This article reviews the application of endosonography for detection of pancreatic masses, staging of pancreatic cancer, detection of pancreatic endocrine tumors, management of cystic pancreatic lesion, diagnosis of chronic pancreatitis, and many other emerging indications. Indications and limitations of endosonography in pancreatic diseases are discussed. The exciting possibilities of EUS-guided intervention in pancreatic diseases and other futuristic indications are explored.

Increased rate of complete EUS staging of patients with esophageal cancer using the nonoptical, wire-guided echoendoscope

BACKGROUND

Incomplete endoscopic ultrasound (EUS) staging procedures in patients with esophageal cancer due to obstructing malignant strictures are prone to underestimate T stage and cannot detect celiac adenopathy. EUS staging in the setting of stenotic malignancies using the large caliber echoendoscope has been complicated by esophageal perforation. We report on the clinical utility of a newly developed, wire-guided echoendoscope for the complete staging of patients with esophageal cancer.

METHODS

Pretreatment EUS examinations performed for esophageal cancer staging were evaluated and the ability to traverse the esophagus and examine the celiac axis were documented. Outcomes before and after the availability of the wire-guided echoendoscope were compared.

RESULTS

One hundred thirty consecutive examinations were evaluated 100 before and 30 after the introduction of the wire-guided echoendoscope. Complete staging was accomplished in 60 of 100 (60%) cases before and 27 of 30 (90%) after its introduction (p = 0.002). The wire-guided echoendoscope was used in 14 of the 30 cases. Despite a trend toward fewer stage T4 tumors, metastatic disease was documented significantly more frequently after the introduction of the esophagoprobe (34% vs. 11%, p = 0.002). There were no complications.

CONCLUSIONS

The introduction of the wire-guided echoendoscope markedly reduced the occurrence of incomplete esophageal cancer staging and improved the detection of metastatic disease.

Perioperative ultrasonography of lymph nodes in patients with gynaecological malignancy

OBJECTIVE

To examine the accuracy of perioperative ultrasonography in detecting pelvic and para-aortic lymph nodes, and to compare the ultrasonographic findings with those observed in histology.

PARTICIPANTS

Forty women with gynaecological malignancy were examined by ultrasonography during their operations before surgical exploration of the lymph nodes; 182 specimens were taken for histological analysis.

MAIN OUTCOME MEASURES

Ultrasonographic findings were compared with histological diagnoses of lymph node biopsies.

RESULTS

Suspicious lymph nodes (diameter > 5 mm) were found in 31 lymph node regions. Seventeen histologically malignant lymph nodes were found. The sensitivity, specificity, and accuracy of finding metastatic lymph nodes by ultrasonography were 71%, 88%, and 87%, respectively. The frequency of false negative ultrasonographic findings was 29%.

CONCLUSIONS

Perioperative ultrasonographic examination can be of use in localising pelvic and paraaortic lymph nodes, especially in laparoscopic operations, where tactile palpation of the retroperitoneal space is not possible. The negative predictive value of the method is high, but the relatively poor sensitivity limits its diagnostic value.