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Biomedical subjects

M B Wallace

Publications and source records attributed to M B Wallace.

At least 19 recordsLinked to original sources
PubMed2006

Molecular diagnostics of non-small cell lung cancer using mediastinal lymph nodes sampled by endoscopic ultrasound-guided needle aspiration.

Non-small cell lung cancer is a common cancer with significant mortality. Accurate and early staging of this cancer has a significant impact on outcome. Endoscopic ultrasound-guided fine needle aspiration of involved mediastinal lymph nodes is critical for staging. Several molecular markers have been identified recently in association with non-small cell carcinoma of the lung that are promising to make early detection of metastatic disease more reliable.

Biomarkers, Tumor↗
PubMed2004

Clinical experience of patients undergoing photodynamic therapy for Barrett's dysplasia or cancer.

INTRODUCTION: Barrett's oesophagus is the most important risk factor in the increase in incidence of oesophageal adenocarcinoma. Photodynamic therapy using porfimer sodium is the only approved endoscopic treatment for use in patients with Barrett's high-grade dysplasia. AIM: To determine clinical characteristics, endoscopic findings and treatment complications in Barrett's high-grade dysplasia patients undergoing photodynamic therapy. METHODS: We reviewed our experience using porfimer sodium photodynamic therapy to treat patients with Barrett's oesophagus and high-grade dysplasia or mucosal carcinoma. Data collected included patients characteristics, presentation symptoms, endoscopic findings, subsequent use of surveillance endoscopy and outcome after photodynamic therapy. RESULTS: Since 1997, 102 patients with Barrett's high-grade dysplasia (69 patients) or mucosal adenocarcinoma (33 patients) have been treated with photodynamic therapy using porfimer sodium as an alternative to oesophagectomy (median series follow-up time = 1.6 years). Almost half (46%) of patients had high-grade dysplasia or carcinoma detected on their first endoscopy and the remainder (54%) were found during surveillance of known Barrett's oesophagus. Symptoms typically associated with oesophageal disease were only found in 29 of 47 (62%) patients in whom dysplasia/carcinoma was detected on the initial endoscopy - chest pain in 13 patients, dysphagia in nine patients and chronic gastro-oesophageal disease in seven patients. Comparison of endoscopic characteristics found the median Barrett's glandular segment length was significantly shorter in adenocarcinoma patients (median 3 cm; range: 1-12) vs. Barrett's high-grade dysplasia patients (median 5 cm; range: 1-16, P < 0.001). Overall treatment results found complete ablation of glandular epithelium with one course of photodynamic therapy in most patients (56%). Stricture requiring dilation occurred in 20 patients (20%) was the most common serious adverse event. Photodynamic therapy failed to ablate dysplasia or carcinoma in four patients and subsequent oesophagectomy was curative in three of these patients. CONCLUSIONS: Approximately 40% of newly diagnosed patients with Barrett's associated dysplasia or carcinoma had no oesophageal symptoms and had carcinoma associated with short segment (3 cm or less). Photodynamic therapy is a highly effective, safe and minimally invasive first-line treatment for patients with Barrett's dysplasia and mucosal adenocarcinoma.

Adenocarcinoma↗
PubMed2004

Comparison of EUS-guided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration.

BACKGROUND AND STUDY AIMS: The accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) depends on immediate specimen review by a cytopathologist. Stromal tumors, lymphoma, and well-differentiated pancreatic cancer are difficult to diagnose on the basis of cytology alone. To overcome these limitations, a 19-gauge Trucut needle has been developed to obtain histological samples at EUS. This pilot study compares the specimen adequacy and diagnostic accuracy of EUS-guided Trucut needle biopsy (EUS-TNB) with EUS-FNA. PATIENTS AND METHODS: A total of 18 patients underwent EUS-TNB and EUS-FNA. The specimen adequacy and diagnostic accuracy of the two techniques was compared. The technical performance and safety profile of the Trucut needle were also evaluated. RESULTS: The EUS-TNB specimen was adequate for evaluation in 15/18 patients compared with 18/18 with EUS-FNA (83 % vs. 100 %, not significant). The diagnostic accuracy of EUS-TNB was not significantly different from EUS-FNA (78 % vs. 89 %). Two complications were encountered: one patient developed mediastinitis and required surgery; another had immediate bleeding that was managed conservatively. One technical problem was encountered: the Trucut needle failed to deploy after two passes when a gastric stromal cell tumor was being biopsied. CONCLUSION: The diagnostic accuracy of the new EUS-TNB is comparable to that of EUS-FNA. In our experience, the overall efficacy and safety profile of the Trucut needle appears modest.

Adrenal Glands↗
PubMed2004

Endoscopic ultrasonography in the diagnosis and staging of neoplasms of the head and neck.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a minimally invasive and highly accurate method of detecting mediastinal lymph-node metastases in gastrointestinal and lung cancer. Little information is available regarding the use of EUS-FNA to stage tumors in the head and neck region. This study reports experience with EUS in the diagnosis and staging of these tumors and their mediastinal spread. PATIENTS AND METHODS: The records of patients who underwent EUS for diagnosis and/or staging of head and neck tumors were reviewed. Referral criteria were suspected invasion of the esophagus by a lower-neck mass on cervical computed tomography (CT) or magnetic resonance imaging (MRI), or mediastinal lymphadenopathy > 10 mm on a chest CT. RESULTS: Thirty-two patients (23 men, nine women; mean age 65 years, range 44 - 80) were referred and underwent 35 EUS examinations. In one patient, EUS was not possible due to a benign esophageal stricture. In 17 patients with suspected esophageal invasion on CT scans, EUS demonstrated invasion of the esophagus in four cases and of the pleura in one; 12 tumors showed no visible invasion of adjacent structures. The other 17 examinations were carried out for suspected mediastinal metastatic disease. In eight cases, EUS-FNA confirmed metastatic disease, whereas only benign changes were shown in the other nine cases. EUS-FNA also provided the first tissue diagnosis in two primary tumors and identified malignancy in one patient with no CT suspicion of positive mediastinal lymph nodes. EUS avoided the need for more invasive investigations in all patients with mediastinal lymphadenopathy, and it changed the management in 12 of the 17 patients (71 %) with suspected esophageal invasion and in eight of the 17 patients (47 %) with suspected mediastinal disease. CONCLUSIONS: EUS with FNA provides a viable approach to the diagnosis and staging of tumors in the head and neck region when there is a suggestion of esophageal invasion on CT or MRI, or enlarged mediastinal lymph nodes. EUS with FNA may avoid the need for mediastinoscopy or other more invasive techniques for staging of these neoplasms.

Adult↗
PubMed2004

Is endosonography guided fine needle aspiration (EUS-FNA) for sarcoidosis as good as we think?

BACKGROUND: Preliminary data show that endosonography guided fine needle aspiration (EUS-FNA) may be an accurate method for diagnosing sarcoidosis. However, these data were obtained in a small selected group of patients with a very high pretest probability of sarcoidosis. This retrospective study reports on the use of EUS-FNA in an unselected group of patients with mediastinal lymphadenopathy of unknown origin. METHODS: The EUS database of a single tertiary referral centre was reviewed for patients who underwent EUS-FNA for mediastinal lymphadenopathy of unknown origin. Clinical presentation and imaging studies of each case were carefully reviewed and the diagnosis "sarcoidosis" or "no sarcoidosis" attributed if possible. The diagnoses were compared with the result of EUS-FNA. RESULTS: One hundred and twenty four patients were investigated. In 35 cases EUS-FNA identified granulomas (group 1); in the other 89 cases (group 2) no granulomas were detected. The definite diagnoses in group 1 were sarcoidosis (n = 25), indefinite (n = 7), no sarcoidosis (n = 3). The definite diagnoses in group 2 were sarcoidosis (n = 3), indefinite (n = 9), no sarcoidosis (n = 77). Of the 77 cases with no sarcoidosis, 44 were diagnosed with other diseases. The other 33 showed non-specific changes in the FNA and sarcoidosis was excluded by negative non-EUS pathology (n = 17) and clinical presentation. The sensitivity and specificity for EUS-FNA were 89% (95% CI 82 to 94) and 96% (95% CI 91 to 98), respectively, after exclusion of the indefinite cases in both groups. CONCLUSIONS: EUS-FNA is an accurate method for diagnosing sarcoidosis in an unselected group of patients with mediastinal lymphadenopathy. The reported sensitivity and specificity must be appreciated in the context of the difficult and often incomplete clinical diagnosis of sarcoidosis.

Adult↗
PubMed2001

Predictors of survival for esophageal cancer patients with and without celiac axis lymphadenopathy: impact of staging endosonography.

BACKGROUND: Esophageal cancer patients with M1a disease are reported to have poor survival. We hypothesized that patients with celiac lymph node metastases (CLN) identified by endoscopic ultrasonography (EUS) would predict a cohort with significantly worse survival postoperatively. Accurate preoperative identification of this group will facilitate future adjuvant studies. METHODS: During the study period, 211 patients with esophageal cancer underwent EUS staging. Patients with evaluable celiac axis (n = 182) were included in this study. Survival of patients with and without CLNs was compared and the factors affecting overall survival were assessed. A subgroup analysis based on CLN status was performed in the subgroup of patients who underwent surgical procedures. RESULTS: Follow-up data was available in 91.2% (166 of 182) of the patients. As staged by EUS, T1, T2, T3, and T4 tumors accounted for 9.3%, 11.5%, 56%, and 21% of the cases, respectively. At least one CLN was imaged by EUS in 40% (72 of 182). The 5-year survival in patients with CLNs detected by EUS was 13% (95% confidence interval, 5% to 21%) compared with 30% (95% confidence interval, 21% to 40%) in patients with no CLNs detected by EUS (p = 0.007). In the subgroup of patients who underwent surgical procedures (n = 68), patients with CLN involvement had worse survival compared with those who did not have malignant involvement of CLNs at the time of their operation (median survival 39.8 versus 13.8 months, p = 0.0008). In a Cox proportional model, adjusting for race and the type of therapy, patients with CLN involvement or advanced EUS American Joint Committee on Cancer stage were more likely to have worse survival (p < 0.05) CONCLUSIONS: EUS base line findings correlate with long term survival in patients with esophageal cancer. Patients with M1a disease as identified by EUS had a significantly worse postoperative survival when compared with non-M1a patients. This cohort of patients will be ideal for the study of induction therapy since the effect of down staging can be assessed before operation.

Adenocarcinoma↗
PubMed2001

Endoscopic ultrasound-guided fine needle aspiration for staging patients with carcinoma of the lung.

BACKGROUND: Endoscopic ultrasound (EUS)-guided fine needle aspiration is a safe, cost-effective procedure that can confirm the presence of mediastinal lymph node metastases and mediastinal tumor invasion. We studied the accuracy of EUS in a large population of lung cancer patients with and without enlarged mediastinal lymph nodes on computed tomographic (CT) scan. METHODS: From 1996 to 2000 all patients referred to our institution with lung tumors and no proven distant metastases were considered for EUS and surgical staging. Patients had endoscopic ultrasound with fine needle aspiration of abnormal appearing mediastinal lymph nodes and evaluation for mediastinal invasion of tumor (stage III or IV disease). Patients without confirmed stage III or IV disease had surgical staging. RESULTS: Two hundred seventy-seven patients met the inclusion criteria, including 121 who had EUS. Endoscopic ultrasound and fine needle aspiration detected stage III or IV disease in 85 of 121 (70%). Among patients with enlarged lymph nodes on CT, 75 of 97 (77%) had stage III or IV disease detected by EUS. Among a small cohort of patients without enlarged mediastinal lymph nodes on CT, 10 of 24 (42%) had stage III or IV disease detected by EUS. For mediastinal lymph nodes only, the sensitivity of endoscopic ultrasound and CT was 87%. The specificity of EUS (100%) was superior to that of CT (32%) (p < 0.001). CONCLUSIONS: Endoscopic ultrasound with fine needle aspiration identified and histologically confirmed mediastinal disease in more than two thirds of patients with carcinoma of the lung who have abnormal mediastinal CT scans. Although mediastinal disease was more likely in patients with an abnormal mediastinal CT, EUS also detected mediastinal disease in more than one third of patients with a normal mediastinal CT and deserves further study. Endoscopic ultrasound should be considered a first line method of presurgical evaluation of patients with tumors of the lung.

Adult↗
PubMed2001

The reliability of EUS for the diagnosis of chronic pancreatitis: interobserver agreement among experienced endosonographers.

BACKGROUND: Endoscopic ultrasound (EUS) is a minimally invasive, low risk method of diagnosis for chronic pancreatitis (CP). The degree to which endosonographers agree on the features and diagnosis of CP is unknown. For EUS to be considered an accurate test for CP, there must be good interobserver agreement. METHODS: Forty-five pancreatic EUS examinations were videotaped by 3 experienced endosonographers. Examinations from 33 patients with suspected CP based on typical symptoms, as well as 12 control patients without suspected CP, were included. Eleven experienced endosonographers ("experts") who were blinded to clinical information independently evaluated all videotaped examinations for the presence of CP and the following 9 validated features of CP: echogenic foci, strands, lobularity, cysts, stones, duct dilatation, duct irregularity, hyperechoic duct margins, and visible side branches. The experts also ranked (most to least) which features they believed to be the most indicative of CP. Interobserver agreement was expressed as the kappa (kappa) statistic. RESULTS: There was moderately good overall agreement for the final diagnosis of CP (kappa = 0.45). Agreement was good for individual features of duct dilatation (kappa = 0.6) and lobularity (kappa = 0.51) but poor for the other 7 features (kappa < 0.4). The expert panel had consensus or near consensus agreement (greater than 90%) on 206 of 450 (46%) individual EUS features including 22 of 45 diagnoses of CP. Agreement on the final diagnosis of CP was moderately good for those trained in third tier fellowships (kappa = 0.42 +/- 0.03) and those with more than 1100 lifetime pancreatic EUS examinations (kappa = 0.46 +/- 0.05). The presence of stones was regarded as the most predictive feature of CP by all endosonographers, followed by visible side branches, cysts, lobularity, irregular main pancreatic duct, hyperechoic foci, hyperechoic strands, main pancreatic duct dilatation, and main duct hyperechoic margins. The most common diagnostic criterion for the diagnosis of CP was the total number of features (median 4 or greater, range 3 or greater to 5 or greater). CONCLUSIONS: EUS is a reliable method for the diagnosis of chronic pancreatitis with good interobserver agreement among experienced endosonographers. Agreement on the EUS diagnosis of chronic pancreatitis is comparable to other commonly used endoscopic procedures such as bleeding ulcer stigmata and computed tomography of the brain for stroke localization and better than the physical diagnosis of heart sounds.

Chronic Disease↗
PubMed2001

Fluorescence, reflectance, and light-scattering spectroscopy for evaluating dysplasia in patients with Barrett's esophagus.

BACKGROUND & AIMS: The aim of this study was to assess the potential of 3 spectroscopic techniques (fluorescence, reflectance, and light-scattering spectroscopy) individually and in combination, for evaluating low- and high-grade dysplasia in patients with Barrett's esophagus (BE). METHODS: Fluorescence spectra at 11 excitation wavelengths and a reflectance spectrum were acquired in approximately 1 second from each site before biopsy using an optical fiber probe. The measured fluorescence spectra were combined with the reflectance spectra to extract the intrinsic tissue fluorescence. The reflectance spectra provided morphologic information about the bulk tissue, whereas light-scattering spectroscopy was used to determine cell nuclear crowding and enlargement in Barrett's epithelium. RESULTS: Significant differences were observed between dysplastic and nondysplastic BE in terms of intrinsic fluorescence, bulk scattering properties, and levels of epithelial cell nuclear crowding and enlargement. The combination of all 3 techniques resulted in superior sensitivity and specificity for separating high-grade from non-high-grade and dysplastic from nondysplastic epithelium. CONCLUSIONS: Intrinsic fluorescence, reflectance, and light-scattering spectroscopies provide complementary information about biochemical and morphologic changes that occur during the development of dysplasia. The combination of these techniques (Tri-Modal Spectroscopy) can serve as an excellent tool for the evaluation of dysplasia in BE.

Barrett Esophagus↗
PubMed2001

An assessment of the potential value of endoscopic ultrasound as a cost-minimizing tool in dyspeptic patients with persistent symptoms.

STUDY AIMS: To quantify resource utilization in dyspeptic patients with persistent symptoms and to determine whether using both the endoscopic and ultrasound capabilities of endoscopic ultrasound could reduce costs. METHODS: Consecutive patients with persistent dyspepsia, after a minimum 1-month trial of acid suppression, underwent endoscopic ultrasound (EUS) and upper endoscopy using the GF-UM20 echo endoscope. Assuming EUS could replace imaging tests which had been requested in addition to upper endoscopy, the hypothetical costs of the EUS-based and upper endoscopy-based strategies were compared. RESULTS: 116 patients with persistent dyspepsia underwent EUS, of whom 64.6 % had > or = 2 imaging procedures, most commonly computed tomography (CT) (70.6 %) and abdominal ultrasound (64.7 %). The number of tests did not correlate strongly with any demographic variables. The fiberoptic echo endoscope provided an adequate endoscopic and ultrasound examination but was damaged by retroflexion. Direct hospital costs were lowest for the EUS-based strategy. Total avoidable cost for 116 patients was $ 4137 to $ 14 121 (or $ 36 to $ 122 per patient), depending on whether upper endoscopy was performed in the non-EUS strategies. CONCLUSIONS: Patients with persistent dyspepsia may undergo multiple abdominal imaging procedures. Clinical variables do not predict the need for additional testing. An EUS-based strategy may reduce overall costs if it prevents additional testing.

Cost-Benefit Analysis↗
PubMed2001

Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy.

BACKGROUND: EUS-guided fine needle aspiration (EUS-FNA) is a highly accurate method of detecting malignant lymphadenopathy. The optimal methods for performing EUS-FNA to maximize sensitivity and to minimize the number of needle passes necessary are unknown. This is a report of the results of a prospective randomized controlled trial to determine the effect of suction, the site of FNA (edge or center of lymph node), and the method of preparation of cytologic specimens on accuracy, number of needle passes needed, and specimen quality. METHODS: Consecutive patients with lymphadenopathy detected by EUS underwent FNA. Each lymph node was sampled with or without suction and from the edge or center in a 2 x 2 factorial design. The samples were expressed onto slides for cytology, and the residual material in the needle was analyzed by the cytospin-cellblock technique. Each aspirate was individually characterized for a diagnosis of malignancy, cellularity, and bloodiness. RESULTS: Forty-three patients with a total of 46 lymph nodes were evaluated. The final lymph node diagnosis was benign in 22 (48%), "suspicious for malignancy" in 6 (13%), and malignant in 18 (39%). The use of suction was associated with an increase in the cellularity of the specimen, but did not improve the likelihood of obtaining a correct diagnosis (OR 1.52: 95% CI [0.81, 2.85]). Samples obtained with suction were of worse quality because of excessive bloodiness (OR 4.7: 95% CI [1.99, 11.24]). Aspiration from the edge of the lymph node (compared with the center) did not increase the likelihood of a correct diagnosis (OR 1.16: 95% CI [0.42, 3.21]). For 78% of malignant lymph nodes, the correct diagnosis was obtained on the first needle pass and for 100% by the third pass. Cytospin-cellblock methods did not add any additional diagnostic information compared with direct smear cytology. CONCLUSIONS: The traditional method of applying suction during EUS-FNA does not improve diagnostic accuracy and worsens specimen bloodiness compared with FNA without suction. The site of FNA within the lymph node does not affect accuracy. When EUS-FNA is necessary, our recommendation is up to 3 FNAs without suction from the most convenient and safe location within abnormal-appearing lymph nodes.

Biopsy, Needle↗