Endoscopic ultrasound errors in esophageal cancer

Impact of endoscopic ultrasonography on the accuracy of T staging in esophageal cancer and factors associated with its accuracy: A retrospective study

The sensitivity and specificity of endoscopic ultrasound (EUS) for esophageal cancer are variable. The aim of the present study was to determine the accuracy of EUS for the T staging of esophageal cancer and to explore the factors that affect the accuracy.This was a retrospective study of patients with esophageal cancer who underwent EUS between January 2018 and September 2019 at the author's hospital. All patients underwent EUS, surgery, and pathological examination. The diagnostic value of ultrasound-based T (uT) staging was evaluated using the pathological T (pT) staging as the gold standard.Finally, 169 patients were included. Among the 169 patients, 37 were overstaged by EUS, 33 were understaged, and 99 were correctly staged. The overall accuracy of EUS was 58.6%. Sensitivity was low, at 0% to 70.8% depending upon the pT stage, but specificity was higher, at 71.0% to 100.0%, also depending upon the pT stage. The multivariable analysis revealed that highly differentiated tumors (odds ratio = 9.167, P = .041) and pT stage ≥T2 (odds ratio = 2.932, P = .004) were independent factors of accurate uT stage.The staging of esophageal cancer using EUS has low sensitivity but high specificity. Highly differentiated tumors and pT stage ≥2 tumors were associated with the accuracy of uT staging.

Clinical Risk Prediction Model for Neoadjuvant Therapy in Resectable Esophageal Adenocarcinoma

GOALS AND BACKGROUND

Clinical staging with endoscopic ultrasound (EUS) and positron emission tomography (PET) is used to identify esophageal adenocarcinoma (EAC) patients with locally advanced disease and therefore, benefit from neoadjuvant therapy. However, EUS is operator dependent and subject to interobserver variability. Therefore, we aimed to identify clinical predictors of locally advanced EAC and build a predictive model that can be used as an adjunct to current staging methods.

STUDY

This was a cross-sectional study of patients with EAC who underwent preoperative staging with EUS and PET scan followed by definitive therapy at our institution from January 2011 to December 2017. Demographic data, symptoms, endoscopic findings, EUS, and PET scan findings were obtained.

RESULTS

Four hundred and twenty-six patients met the study criteria, of which 86 (20.2%) patients had limited stage EAC and 340 (79.8%) had locally advanced disease. The mean age was 65.4±10.3 years of which 356 (83.6%) were men and 393 (92.3%) were White. On multivariable analysis, age (above 75 or below 65 y), dysphagia [odds ratio (OR): 2.84], weight loss (OR: 2.06), protruding tumor (OR: 2.99), and tumor size >2 cm (OR: 3.3) were predictive of locally advanced disease, while gastrointestinal bleeding (OR: 0.36) and presence of visible Barrett's esophagus (OR: 0.4) were more likely to be associated with limited stage. A nomogram for predicting the risk of locally advanced EAC was constructed and internally validated.

CONCLUSIONS

We constructed a nomogram to facilitate an individualized prediction of the risk of locally advanced EAC. This model can aid in decision making for neoadjuvant therapy in EAC.

Early Esophageal Cancer: What the Gastroenterologist Needs to Know

Endoscopic findings in early esophageal cancer are often subtle and require careful inspection and meticulous endoscopic examination. When dysplasia is suspected, we recommend performing 1 or 2 targeted biopsies of the abnormal area and review with a pathologist specialized in evaluating gastrointestinal diseases. In the case of adenocarcinoma, after resection of any visible cancer, residual Barrett's can be treated by ablation. Endoscopic resection can offer the opportunity for patients to avoid surgery. Further studies are needed to evaluate the optimal management of circumferential and near-circumferential lesions as well as tools and techniques to facilitate the performance of endoscopic submucosal dissection and endoscopic mucosal resection.

Prognostic value of tumor length and diameter for esophageal squamous cell cancer patients treated with definitive (chemo)radiotherapy: Potential indicators for nonsurgical T staging

PURPOSE

The aim of this work was to evaluate the prognostic value of tumor length and diameter for patients with esophageal squamous cell cancer (ESCC) treated with definitive (chemo)radiotherapy to identify potential indicators for separate nonsurgical T staging, which are needed in clinical practice.

MATERIALS AND METHODS

A total of 682 patients with ESCC who underwent definitive (chemo)radiotherapy between 2009 and 2015 were reviewed. Esophageal tumor length and diameter were determined by barium esophagography and computed tomography before treatment. Univariate and multivariate analyses were used to assess the impact of tumor length and diameter on long-term overall survival (OS) and progression-free survival (PFS). Propensity score matching (PSM) analysis was also used to control intergroup heterogeneity.

RESULTS

The median OS and PFS were 22.2 months and 15.4 months, respectively, in the tumor length ≤ 6 cm group, which were significantly longer than those in the tumor length > 6 cm group (13.4 and 8.5 months, respectively). The median OS and PFS were 23.3 months and 15.9 months, respectively, in the tumor diameter ≤ 3.5 cm group, which were also significantly longer than those in the tumor diameter > 3.5 cm group (13.3 and 8.8 months, respectively). Similar results were found after PSM. Univariate and multivariate analyses showed that tumor length and diameter were both independent predictors of long-term survival.

CONCLUSION

Tumor length and diameter are both independent prognostic factors for ESCC patients treated with definitive (chemo)radiotherapy. These two imaging parameters have the potential for development and use in nonsurgical T staging.

Prognostic significance of tumor length in patients receiving esophagectomy for esophageal cancer

AIMS

We investigated the prognostic value of tumor length measurements acquired both from pre-operative imaging and post-operative pathology in esophageal cancer.

METHODS

Tumor lengths were examined retrospectively for 389 esophagectomy patients with respect to Endoscopy, EUS (Endoscopic Ultrasound), CT and PET-CT, and pathology. Correlations between the measurements on the different approaches were assessed, and associations between tumor length and survival were analyzed.

RESULTS

Only the tumor lengths assessed on pathology were found to be significantly associated with overall (P = 0.001) and recurrence free (P < 0.001) survival on univariable analysis. The median overall survival was 47.1 months in those patients with tumor lengths <3.0 cm, falling to 19.6 and 18.0 months in those with 3.0-4.4 and 4.5+ cm tumors, respectively, demonstrating a reduction in patient survival at a tumor length of around 3 cm. Tumor length on pathology was significantly correlated with tumor differentiation and both T- and N-categories. After accounting for these factors, tumor length on pathology was a significant independent predictor of recurrence-free (P = 0.016), but not overall (P = 0.128) survival.

CONCLUSIONS

Tumor lengths on pathology were found to be the most predictive of patient outcome. However, after accounting for other tumor-related factors, tumor length only resulted in a marginal improvement in predictive accuracy.

Role of EUS in patients with suspected Barrett's esophagus with high-grade dysplasia or early esophageal adenocarcinoma: impact on endoscopic therapy

BACKGROUND AND AIMS

Endoscopic therapy is the standard treatment for high-grade dysplasia and some cases of T1a esophageal adenocarcinoma (EAC), but it is not appropriate for deeply invasive disease. Data on the value of EUS for patient selection for endoscopic or surgical resection are conflicting. We investigated the outcome of esophageal EUS for the staging and treatment selection of patients with treatment-naive, premalignant Barrett's esophagus (BE) and suspected superficial EAC.

METHODS

We retrospectively reviewed consecutive patients who underwent EUS for staging of treatment-naive, suspected premalignant BE and superficial EAC from January 2006 to June 2014. All patients referred for endoscopic therapy routinely underwent EUS. Patients with esophageal masses, squamous cell cancers, previous neoadjuvant therapy, or unrelated pathologies were excluded. Each patient's final diagnosis was verified by EMR, esophagectomy, or forceps biopsy sampling. Test characteristics of EUS were calculated.

RESULTS

Three hundred thirty-five patients (mean age, 68 years; 86% male) with BE, a Prague C mean of 2.8 cm, and a Prague M mean of 4.5 cm were staged (pT0, 78% [6% nondysplastic, 24% low-grade dysplasia, 42% high-grade dysplasia]; pT1a, 14%; pT1b, 7%; and pT2, 1%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for patient selection to endoscopic (T1aN0 or less) or surgical therapy with EUS TN staging were 50%, 93%, 40%, 95%, and 90%, respectively. Comparable rates were achieved for patients with nodular BE. Overstaging occurred in 7% of patients, and EUS selected 11% for incorrect treatment modalities compared with pathologic staging.

CONCLUSIONS

This study confirms the limited value of EUS suggested in the latest American College of Gastroenterology guidelines for BE management.

Correlation between endoscopic forceps biopsies and endoscopic mucosal resection with endoscopic ultrasound in patients with Barrett's esophagus with high-grade dysplasia and early cancer

BACKGROUND

Patients with Barrett's esophagus (BE) and high-grade dysplasia (HGD) or intramucosal cancer (IMC) on endoscopic forceps biopsies are referred to endoscopic therapy even though forceps biopsies do not reflect the disease extent accurately. Endoscopic mucosal resection (EMR) and endoscopic ultrasound (EUS) are frequently used for staging prior to endoscopic therapy. Our aims were to evaluate: (1) if endoscopic forceps biopsies correlated with EMR histology in these patients; (2) the utility of EUS compared to EMR; and (3) if accuracy of EUS varied based on grade of differentiation of tumor.

METHODS

This is a retrospective review of patients referred to endoscopic therapy of BE with HGD or early esophageal adenocarcinoma (EAC) who underwent EMR from 2006 to 2011. Age, race, sex, length of Barrett's segment, hiatal hernia size, number of endoscopies and biopsy results and EUS findings were abstracted.

RESULTS

A total of 151 patients underwent EMR. In 50 % (75/151) of patients, EMR histology was consistent with endoscopic forceps biopsy findings. EMR resulted in change in diagnosis with upstaging in 21 % (32/151) and downstaging in 29 % (44/151). In patients with HGD on EMR, EUS staging was T0 in 74.1 % (23/31) but upstaged in 25.8 % (8/31). In patients with IMC on EMR, EUS findings were T1a in 23.6 % (9/38), upstaged in 18.4 % (7/38) and downstaged in 57.8 % (22/38). EUS accurately identified EMR histology in all submucosal cancers. Grade of differentiation was reported in 24 cancers on EMR histology. There was no correlation between grade and EUS staging.

CONCLUSIONS

EUS is of limited utility in accurate staging of BE patients with HGD or early EAC. Endoscopic forceps biopsy correlated with EMR findings in only 50 % of patients. Irrespective of the endoscopic forceps biopsy results, all BE patients with visible lesions should be referred to EMR.

Treatment Strategy after Endoscopic Resection of Superficial Esophageal Squamous Cell Carcinoma: A Single Institution Experience

BACKGROUND/AIMS

The aim of this study was to analyze and propose a treatment strategy after endoscopic resection of superficial esophageal squamous cell carcinoma in a single institution.

METHODS

This is a retrospective review of 37 patients who were treated by endoscopic resection during a 6-year period.

RESULTS

The mean tumor size was 11.5±5.5 mm (range, 3 to 31 mm). Thirty-one lesions (83.8%) were treated by endoscopic submucosal dissection, and six lesions were treated by endoscopic mucosal resection (16.2%). The en bloc resection rate and complete resection rate were 91.9% and 81.8%, respectively. The tumor invasion depth was diagnosed as epithelial in five cases (13.5%), lamina propria mucosa in 12 cases (32.4%), muscularis mucosa in 10 cases (27.0%) and submucosa in 10 cases (27.0%). The complication rate was 13.5% and included three cases (8.1%) of perforation. Ten patients who had muscularis mucosa and submucosa lesions received additional treatments, including six patients who were treated with esophagectomy, three patients who were treated with radiotherapy and one patient who was treated with chemoradiotherapy. One patient with lamina propria lesions received radiotherapy due to a positive resection margin. The median follow-up duration was 22 months (range, 4 to 79 months), and no recurrence or metastasis was noted during follow-up.

CONCLUSIONS

Tailored management after endoscopic treatment of superficial esophageal squamous cell carcinoma can offer an acceptable oncologic outcome in early esophageal carcinoma.

Treatment of clinical T2N0M0 esophageal cancer

BACKGROUND

Management of clinical T2N0M0 (cT2N0M0) esophageal cancer remains controversial. We reviewed our institutional experience over 21 years (1990-2011) to determine clinical staging accuracy, optimal treatment approaches, and factors predictive of survival in this patient population.

METHODS

Patients with cT2N0M0 esophageal cancer determined by endoscopic ultrasound (EUS) were identified through a prospectively collected database. Demographics, perioperative data, and outcomes were examined. Cox regression model and Kaplan-Meier plots were used for statistical survival analysis.

RESULTS

A total of 731 patients underwent esophagectomy, of whom 68 cT2N0M0 patients (9 %) were identified. Fifty-seven patients (84 %) had adenocarcinoma. Thirty-three patients (48.5 %) were treated with neoadjuvant chemoradiation followed by surgery, and 35 underwent surgical resection alone. All resections except one included a transthoracic approach with two-field lymph node dissection. Thirty-day operative mortality was 2.9 %. Only 3 patients (8.5 %) who underwent surgery alone had T2N0M0 disease identified by pathology: the disease of 15 (42.8 %) was found to be overstaged and 17 (48.5 %) understaged after surgery. Understaging was more common in poorly differentiated tumors (p = 0.03). Nine patients (27.2 %) had complete pathologic response after chemoradiotherapy. Absence of lymph node metastases (pN0) was significantly more frequent in the neoadjuvant group (29 of 33 vs. 21 of 35, p = 0.01). Median follow-up was 44.2 months. Overall 5-year survival was 50.8 %. On multivariate analysis, adenocarcinoma (p = 0.001) and pN0 after resection (p = 0.01) were significant predictors of survival.

CONCLUSIONS

EUS was inaccurate in staging cT2N0M0 esophageal cancer in this study. Poorly differentiated tumors were more frequently understaged. Adenocarcinoma and absence of lymph node metastases (pN0) were independently predictive of long-term survival. pN0 status was significantly more common in patients undergoing neoadjuvant therapy, but long-term survival was not affected by neoadjuvant therapy. A strategy of neoadjuvant therapy followed by resection may be optimal in this group, especially in patients with disease likely to be understaged.

The role of induction therapy

The incidence of esophageal cancer has been steadily increasing. The 5-year survival of esophageal cancer has minimally improved over the past 30 years. In this article, we review the management of esophageal cancer, focusing on the literature investigating the role of induction chemotherapy and radiation therapy.

Appraisal of staging endoscopic ultrasonography in a modern high-volume esophageal program

BACKGROUND

Accurate pretreatment staging is essential to decision making for patients with esophageal and junctional cancers, particularly when choosing endoscopic therapy or a multimodal approach. As the efficacy of endoscopic ultrasonography (EUS) has been reported as variable, we assessed it prospectively in a large cohort from a high-volume center.

METHODS

The EUS data from 2007 to 2011 were reviewed and analyzed. We conducted a comparative analysis with computed tomography-positron emission tomography (CT-PET) staging and pathology. Survival was analyzed by Kaplan-Meier testing on EUS-predicted T- and N-stage cohorts.

RESULTS

Altogether, 222 patients underwent EUS. Among patients undergoing primary surgical resection, preoperative EUS diagnosed the T stage correctly in 71 % (55/77) of cases. Sensitivity and specificity for T1, T2, and T3 tumors were 94 and 89 %, 55 and 80 %, and 66 and 93 %, respectively. Mean maximum standard uptake volume on CT-PET correlated moderately with the EUS T stage (r = 0.42, p < 0.0001). EUS accuracy for nodal disease was 65 %. Survival was statistically better for the EUS T1 group than for those with T3 tumors (p = 0.01). Nodal metastases diagnosed on EUS predicted a significantly worse prognosis than EUS-negative nodes on both univariate and multivariate analyses (p < 0.0001 and p = 0.005 respectively).

CONCLUSIONS

There was a significant relation between EUS T and N stages and overall survival. EUS demonstrated 71 % accuracy for the overall T stage. Staging accuracy of EUS for large lesions was less effective than for T1 tumors, underlining the need for a multimodal investigative approach to stage esophageal tumors accurately.

Computed tomography scan as a tool to predict tumor T category in resectable esophageal squamous cell carcinoma

BACKGROUND

The purpose of this study was to determine whether the degree of esophageal circumferential tumor involvement and tumor size of resectable esophageal squamous cell carcinoma (ESCC) assessed on computed tomography could predict T category.

METHODS

One hundred eighty-five consecutive patients with ESCC underwent radical esophagectomy less than 3 weeks after contrast-enhanced computed tomography. The degree of esophageal circumferential tumor involvement and tumor size of ESCC expressed as tumor length, maximal thickness, and gross tumor volume were evaluated on computed tomography. Statistical analyses were performed to identify whether degree of esophageal circumferential tumor involvement and tumor size could predict T category.

RESULTS

Esophageal squamous cell carcinoma with whole esophageal circumferential tumor involvement was more likely to be at T3 category, whereas tumor without this involvement was more likely to be at T1 or T2 category (p < 0.001). Degree of esophageal circumferential tumor involvement could distinguish ESCC at T1/T2 from ESCC at T3 category with a sensitivity of 77.4% and specificity of 74.8%. Tumor length, maximal thickness, and gross tumor volume increased with advancing T category (p < 0.001). Mann-Whitney tests showed that tumor size could distinguish T category (p < 0.001). Compared with degree of esophageal circumferential tumor involvement, tumor length, and maximal thickness, gross tumor volume could be a better differentiating indicator between T1 and T2 categories (cutoff, 5.15 cm(3)), between T1 and T3 categories (cutoff, 11.1 cm(3)), between T2 and T3 categories (cutoff, 17.75 cm(3)), and between T1/T2 and T3 categories (cutoff, 15.9 cm(3)), with sensitivity of 81.3%, 88.8%, 68.8%, and 78.8%, and specificity of 76%, 88%, 67.5%, and 75.4%, respectively.

CONCLUSIONS

Gross tumor volume of resectable ESCC measured with computed tomography could be a recommended indicator for predicting T category.

Clinical value of multiband mucosectomy for the treatment of squamous intraepithelial neoplasia of the esophagus

BACKGROUND AND AIM

To evaluate the clinical value of multiband mucosectomy (MBM) for the treatment of squamous intraepithelial neoplasia of the esophagus.

METHODS

A total of 51 lesions located at esophagus from 43 patients were treated with MBM, among which 11 were diagnosed as middle-grade intraepithelial neoplasia, 25 as high-grade intraepithelial neoplasia, and 15 as early esophageal cancer pathologically. Primary end-points were the rate of complete endoscopic resection and the mean operation time; the second end-points were the postoperative local recurrence rate and acute plus early complications. The histopathological results were compared between pre-MBM biopsy and MBM specimens. All patients were followed up endoscopically.

RESULTS

A total of 52 MBM procedures with 180 resections were performed in 43 patients. The complete endoscopic resection was achieved in 92.3% (95% confidence interval [CI] 81.8-96.9%). The sizes of the lesions ranged from 10 × 8 mm to 25 × 23 mm. The mean operation time is 37 ± 5 min. The operative acute bleeding complication was 7.6% (95% CI 3-18.1%); no perforations occurred. Early complications consisted of delayed bleeding (one patient 1.9%; 95% CI 0.3-10.1%) and slight esophageal stenosis (one patient). The histopathological diagnosis of 26 cases (51%) was consistent between biopsy and MBM samples, while 20 lesions exhibited higher grade dysplasia. The local recurrence rate was 6.9% (3/43) at 1 year, 9.3% (4/43) at 2 years, and 9.3% at 2.5 years. No death occurred during follow-up.

CONCLUSIONS

MBM is a safe and effective technique for the treatment of early esophageal cancer and precancerous lesions.

The impact of time elapsed between endoscopic ultrasound and esophagectomy on concordance of ultrasonographic and pathologic staging of esophageal malignancy

BACKGROUND

Endoscopic ultrasound (EUS) is frequently used for staging of esophageal malignancies prior to esophagectomy.

AIMS

The purpose of this study was to evaluate the effect of elapsed time between endoscopic ultrasound (EUS) staging and esophagectomy on the accuracy of EUS T- and N-staging.

METHODS

This was a retrospective case series of 45 patients with esophageal malignancy who underwent staging EUS and subsequent esophagectomy at our center without neoadjuvant therapy between 2000 and 2009. The main outcome measurements were accuracy of EUS T- and N-staging when compared with surgical pathology.

RESULTS

EUS staging was accurate in 55.6% of patients for tumor stage, and in 75.6% of patients for nodal stage. The median time between EUS and esophagectomy was 26 days (range 3-64). Among patients with surgery performed 3-15, 16-30, and 31-64 days after EUS, EUS tumor staging was accurate in 90.9, 47.4, and 40.0%, respectively (P = 0.02). EUS nodal staging among patients with surgery performed 3-15, 16-30, or 31-64 days after EUS was accurate in 63.6, 84.2, and 73.3% of cases, respectively (P = 0.44). Among the 20 patients for whom T-stage was discordant, 45% were understaged and 55% were overstaged by EUS. There were 11 patients in whom N-stage was discordant; 45.5% were understaged and 54.5% were overstaged.

CONCLUSIONS

Pathologic T-staging is concordant with EUS T-staging when esophagectomy is performed within 15 days of endoscopic evaluation. Correlation between EUS and pathologic N-staging is unlikely to be affected by length of time between EUS and esophagectomy.

Barrett's: evolving techniques for dysplasia detection and endoscopic resection

Advanced endoscopic imaging techniques have made the early diagnosis of neoplastic lesions in Barrett's esophagus easier. A new chapter in minimal invasive cancer therapy has been opened. Endoscopic treatment of early neoplasia in Barrett's esophagus (high-grade intraepithelial neoplasia and mucosal adenocarcinoma) has become the method of choice in most countries. Long-term results for endoscopic treatment in a large group of patients are now available. These emerging data suggest that endoscopic therapy is safe and highly effective with long-term complete remission rates of more than 94%. All visible lesions should be treated by endoscopic resection for histologic confirmation of the neoplastic lesion rather than by ablative techniques. After successful endoscopic resection of all visible and localizable high-grade intraepithelial neoplasia and mucosal cancer, ablative treatment of the remaining Barrett's epithelium at risk should be performed to reduce the rate of recurrent or metachronous neoplasia.

Accuracy of hydro-multidetector row CT in the local T staging of oesophageal cancer compared to postoperative histopathological results

OBJECTIVE

To evaluate the accuracy of multidetector computed tomography with water filling (Hydro-MDCT) in the T-staging of patients with oesophageal cancer.

MATERIALS AND METHODS

There were 131 consecutive patients who were preoperatively and prospectively examined in the prone position on arterial phase contrast-enhanced MDCT, after ingestion of 1,000-1,500 ml tap water and effervescent granules. Two readers staged the local tumour growth (T-staging) independently. They assessed tumour location, size, presence of stenosis, and morphology of the outer border of the oesophageal wall and perioesophageal fat planes on CT. CT findings were compared with histopathological results from resected specimens. Data were analyzed using the SPSS statistical package.

RESULTS

Both readers obtained a high sensitivity of 95% and a high positive predictive value of 96%. Accurate local staging was achieved in 76.3% and 68.7% for readers 1 and 2, respectively. Inter-reader agreement was excellent (weighted κ value of 0.93 and un-weighted κ of 0.89).

CONCLUSION

Using the hydro-technique and applying specific assessment criteria, MDCT appears to be an accurate, non-invasive diagnostic tool for local tumour staging of oesophageal cancer.

Staging of early adenocarcinoma in Barrett's esophagus

The main goal in the staging of patients with early neoplasia arising in the context of Barrett's esophagus (BE) is to identify individuals who are eligible for endoscopic therapy and differentiate them from those who require surgical management. To make the proper patient selection a combined staging strategy consisting of endoscopy evaluation, endoscopic ultrasonography, and endoscopic mucosal resection is necessary. In this article, the authors summarize the evidence behind each different staging modality in the setting of early BE adenocarcinoma and propose a staging approach that helps to select patients who are suitable for endoscopic therapy.

Quality indicators of surgery for adenocarcinoma of the esophagus and gastroesophageal junction

Surgical treatment of adenocarcinoma of the esophagus and gastroesophageal junction is complex and challenging. Huge variation exist in the immediate and long term outcomes of such interventions and it is generally accepted that this is a direct consequence of the experience of the surgical team. However beside surgical quality many other indicators of quality management may influence outcome. Definition of the gastroesophageal junction remains controversial and the performance of staging procedures i.e. CT scan, endoscopy and fine needle aspiration, PET scan still suboptimal. As a result there is disagreement on the selection of patients for surgery, type of surgical approach in particular in relation to the extent of lymph node dissection as well as the extent of esophageal and/or gastric resection. In the design of randomized controlled trials comparing primary surgery versus multimodality treatment surgical quality criteria are notoriously lacking. It therefore remains a matter of debate which patients eventually will benefit from primary surgery versus those who will benefit from induction therapy. A lack of surgical quality indicators is also very prominent when assessing the value of new surgical technologies such as minimally invasive surgery or robotic surgery. Improvements in this wide spectrum of aspects is mandatory and will certainly be of great value to further improve both short and long term outcome after surgery for these complex cancers.

Greater interobserver agreement by endoscopic mucosal resection than biopsy samples in Barrett's dysplasia

BACKGROUND & AIMS

Endoscopic mucosal resection (EMR) is an important diagnostic, staging, and therapeutic tool for patients with Barrett's esophagus (BE)-associated neoplasia. We analyzed the histopathologic characteristics of specimens collected during EMR compared with biopsy specimens from patients with BE and assessed interobserver variability in pathologists' assessment of EMR and biopsy specimens.

METHODS

We evaluated EMR (n = 251) and biopsy (n = 269) specimens collected from patients with BE at 2 tertiary referral centers. A detailed histologic analysis was performed for each EMR and biopsy specimen to determine the grade of dysplasia, depth of the specimen, proportion of specimen with dysplasia, and quality of samples. Interobserver agreement for both biopsy and EMR specimens (among 4 experienced pathologists) was calculated by using kappa statistics.

RESULTS

Histologic analysis showed that submucosa was present in the majority of EMRs, compared with biopsy specimens (88% vs 1%, P < .0001). Almost all biopsy specimens (99%) included lamina propria. However, the muscularis mucosa was observed in only 58% of biopsy specimens. For both EMR and biopsy specimens, the highest grade of dysplasia comprised < or =25% of the total area in >50% of the specimens. Interobserver agreement on the diagnosis of dysplasia was significantly greater for EMR specimens than biopsy specimens (low-grade dysplasia, 0.33 vs 0.22, P < .001; high-grade dysplasia, 0.43 vs 0.35, P = .018).

CONCLUSIONS

Submucosa can be examined in most samples collected from EMR; the distribution of neoplasia is focal within biopsy and EMR specimens. There is more interobserver agreement among pathologists in the analysis of EMR samples than biopsy specimens for the diagnosis of dysplasia.

Prognostic significance of endoluminal ultrasound-defined disease length and tumor volume (EDTV) for patients with the diagnosis of esophageal cancer

BACKGROUND

This study aimed to assess the prognostic significance of endoluminal ultrasound-defined total length of disease and endoluminal ultrasound defined tumor volume (EDTV) in esophageal cancer. The hypothesis was that endoscopic ultrasound (EUS)-defined total length of disease and EDTV are both significant prognostic indicators and better predictors of outcome than endoscopic tumor length.

METHODS

In this study, 174 consecutive patients (median age, 64 years and 128 months) underwent specialist EUS, and the maximum potential EDTV was calculated (pir(2) L, where r is the tumor thickness and L is the total length of disease) including proximal and distal lymph node metastases. Of the 174 patients, 104 underwent surgery (70 had neoadjuvant chemotherapy), 60 underwent definitive chemoradiotherapy, and 10 had palliative therapy.

RESULTS

Survival was related to EUS T stage (p = 0.013), EUS N stage (p = 0.001), EUS M1a stage (p = 0.004), EUS disease length (<8 cm; p = 0.001), and EDTV (all patients <25 cm(3), p = 0.001; surgical patients <40 cm(3), p = 0.036). Forward conditional multivariate analysis showed three factors to be associated with survival: EUS N stage (hazard ratio [HR], 1.646; 95% confidence interval [CI], 1.041-2.602; p = 0.033), EUS M1a stage (HR, 2.702; 95% CI, 1.069-6.830; p = 0.036), and EDTV (HR, 2.702; 95% CI, 1.069-6.830; p = 0.025). Median and 2-year survival for EDTV <25 cm(3) versus >25 cm(3) was 43.4 months and 56%, respectively, compared with 23.5 months and 35%.

CONCLUSIONS

In this study, EDTV based on total EUS-defined length of disease emerged as a new and important prognostic indicator for patients with esophageal cancer.

Endoscopic resection for Barrett's high-grade dysplasia and early esophageal adenocarcinoma: an essential staging procedure with long-term therapeutic benefit

OBJECTIVES

Patients with Barrett's high-grade dysplasia (HGD) or early esophageal adenocarcinoma (EAC) that is shown on biopsy alone continue to undergo esophagectomy without more definitive histological staging. Endoscopic resection (ER) may provide more accurate histological grading and local tumor (T) staging, definitive therapy, and complete Barrett's excision (CBE); however, long-term outcome data are limited. Our objective was to demonstrate the effect on histological grade or local T stage, efficacy, safety and long-term outcome of ER for Barrett's HGD/EAC and of CBE in suitable patients.

METHODS

This prospective study at two Australian academic hospitals involved 75 consecutive patients over 7 years undergoing ER for biopsy-proven HGD or EAC, using multiband mucosectomy or cap technique. In addition, CBE by 2-3-stage radical mucosectomy was attempted for all Barrett's segments<or=3 cm in length in patients aged<75 years with minimal comorbidities.

RESULTS

Biopsy histology showed HGD in 89% of patients and EAC in 11%. However, ER histology resulted in altered grading or staging in 48% of patients (down 28%, up 20%), with HGD in 53%, low-grade dysplasia (LGD) in 19%, mucosal adenocarcinoma in 13%, submucosal adenocarcinoma in 9%, and no dysplasia in 4% of patients. The CBE success rate was 94%. Complications were one aspiration (hospitalization with full recovery) and six strictures successfully dilated endoscopically. During the mean follow-up of 31 months (range 3-89), there was no recurrence at ER sites, 11% developed metachronous lesions and five patients underwent esophagectomy for ER-demonstrated submucosal invasion. Esophagectomy specimens were T0N0M0 in three and T1N0M0 in two patients. There were no deaths due to adenocarcinoma.

CONCLUSIONS

ER alters histological grade or local T stage in 48% of patients and dramatically reduces esophagectomy rates by providing safe and effective therapy. ER has a high success rate (94%) for CBE in short segment Barrett's esophagus.

Endoscopic versus surgical therapy for early cancer in Barrett's esophagus: a decision analysis

BACKGROUND

Esophagectomy for early esophageal adenocarcinoma is associated with increased operative mortality and morbidity, but possibly a decreased recurrence rate compared with endoscopic therapy when using EMR and radiofrequency ablation.

OBJECTIVE

To compare the cost-effectiveness of esophagectomy and endoscopic therapy in the treatment of early esophageal adenocarcinoma.

DESIGN

Decision analysis model.

MAIN OUTCOME MEASUREMENTS

Incremental cost-effectiveness ratio.

RESULTS

During the 5-year study period, endoscopic therapy cost $17,000.00 and yielded 4.88 quality-adjusted life years, compared with $28,000.00 and 4.59, respectively, for esophagectomy. Varying the recurrence rates of cancer or Barrett's esophagus metaplasia after endoscopic therapy did not change the overall outcome. The sensitivity analysis demonstrated, however, that the outcome depended on the rate of lymph node involvement and operative mortality. Under the best of circumstances in favor of esophagectomy, such as 2% operative mortality, no reduced quality of life after esophagectomy, and a low 5-year survival rate after recurrence of endoscopic ablation, the risk of positive lymph nodes still needed to exceed 25% before esophagectomy became the preferred treatment option. This threshold is twice as high as the values reported for early submucosal cancer invasion.

LIMITATIONS

Limited data are available about the long-term outcome of EMR and radiofrequency ablation.

CONCLUSIONS

Endoscopic therapy for early Barrett's esophagus adenocarcinoma is more effective and less expensive than esophagectomy. Even in early esophageal adenocarcinoma with submucosal invasion, endoscopic therapy is a cost-effective alternative to esophagectomy, especially in patients with a high operative risk.

Prognostic significance of endoscopic ultrasound-defined pleural, pericardial or peritoneal fluid in oesophageal cancer

BACKGROUND

Endoscopic ultrasound (EUS) is known to detect smaller effusion volumes than computerised tomography (CT), yet the outcomes for patients diagnosed with oesophageal carcinoma and EUS-defined pleural, pericardial or ascitic fluid effusions (EDFE) are unknown. The aim of this study was to determine the outcome of multidisciplinary stage directed treatment for such patients.

METHODS

Forty-nine (9.2%) out of a consecutive 527 patients diagnosed with oesophageal cancer from a single regional upper gastrointestinal (GI) cancer network were found to have evidence of EDFE undetected by CT. Thirty-nine (79.6%) patients had pleural effusions, eight (16.3%) pericardial effusions, and two (4.1%) ascites.

RESULTS

Twelve (24.4%) underwent surgery, 3 (6.1%) received neoadjuvant chemotherapy without subsequent surgery, 12 (24.5%) received definitive chemoradiotherapy (dCRT), and 22 (44.9%) received palliative treatment. Survival in patients with EDFE was significantly shorter (median and 2-year survival 15.6 months and 24%, respectively) when compared with patients without EDFE (26.7 months and 40%, respectively, p = 0.001), and was unrelated to EDFE type (p = 0.192). Two-year survival after oesophagectomy with or without neoadjuvant therapy was 45% in patients with EDFE compared with 42% in patients without EDFE (p = 0.668).

CONCLUSIONS

EDFE was an important adverse prognostic indicator, but patients deemed to have operable tumours should still be treated with radical intent.

Modern surgery for esophageal cancer

Primary treatment of carcinoma of the esophagus and cardia rests on surgical resection. Although recent advances have shown the suitability of endoscopic treatment in selected patients with very early cancers, and preliminary studies have suggested that responders to primary chemoradiation may be equivalent to resection in selected patients with squamous cell carcinoma, surgical resection remains the mainstay of therapy, as it has for the past 50 years. Various changes support highly individualized treatment decisions, in which each patient receives the treatment with the best chance of eliminating all disease.

Current utilization and performance status of endoscopic ultrasound in a community hospital

OBJECTIVE

Endoscopic ultrasound (EUS) is an essential tool for cancer staging and investigating gastrointestinal diseases. Although it is not a widespread skill, as its expanded indications became much more advanced so did its popularity and hospital acceptance. We aimed to study the utilization and indications of upper EUS in a Hong Kong community hospital. The secondary aim was to assess our accuracy in staging of esophageal and gastric cancer and in evaluating submucosal tumors.

METHODS

All patients who had undergone upper EUS in Tuen Mun Hospital from January 2002 to December 2006 were recruited. Their background data, indications, radiological investigations, upper endoscopy and operation records and histopathologic results were retrieved for analysis. The accuracy of EUS in esophageal cancer staging, gastric cancer staging and evaluating submucosal tumors was assessed by comparing surgical and histopathologic findings.

RESULTS

A total of 645 upper EUS examinations were performed and there has been a steady increase in EUS utilization in our hospital. The most common indications were evaluating submucosal tumors and staging esophageal and gastric cancer. The accuracy of T and N staging of esophageal cancer was 71.2 and 79.7%, respectively and for gastric cancer was 64.0 and 74.7%, respectively. Endoscopic ultrasound was 70% accurate in identifying lesions arising from the submucosal layer and 100% accurate in identifying lesions from the muscularis propria.

CONCLUSION

Endoscopic ultrasound is an accurate method and its demand is increasing. The performance in a community hospital can be further improved and its utilization should expand to other indications.

Significance of neoplastic involvement of margins obtained by endoscopic mucosal resection in Barrett's esophagus

OBJECTIVES

Although EMR has been used for elimination of neoplasia in BE, the significance of positive carcinoma margins and depth of invasion on endoscopic resection pathology has not been assessed using a valid standard. The aim of this study was to assess the accuracy of tumor staging by EMR using esophagectomy as the standard.

METHODS

Medical records of patients, who underwent endoscopic resection for esophageal carcinoma or high-grade dysplasia in BE followed by esophagectomy, were reviewed. Data were abstracted from a prospectively maintained EMR database. Endosonography and endoscopic resection were performed by a single experienced endoscopist. Two experienced GI pathologists interpreted all histological results. Standard statistical tests were used to compare continuous and categorical variables.

RESULTS

Twenty-five patients were included in the study. Three patients had mucosal carcinoma and 16 had submucosal carcinoma following endoscopic resection. Surgical pathology staging was consistent with preoperative EMR staging in all patients. No patient with negative mucosal resection margins had residual tumor at the resection site at esophagectomy. In patients with submucosal carcinoma, 8 had residual carcinoma at the EMR site at surgery and 5 patients had metastatic lymphadenopathy.

CONCLUSIONS

Tumor staging using EMR pathology is accurate when compared with surgical pathology following esophagectomy. Negative margins on EMR pathology correlate with absence of residual disease at the EMR site at esophagectomy. Submucosal carcinoma on EMR specimens was associated with a high prevalence of residual disease at surgery (50%) and metastatic lymphadenopathy (31%).

Esophageal endoscopic ultrasound fine-needle aspiration as a diagnostic tool

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) may be employed for procurement of a tissue diagnosis in a minimally invasive fashion. In many cases, EUS-FNA excludes the need for more invasive diagnostic procedures when a tissue diagnosis is required. In patients with esophageal neoplasms, EUS-FNA is a safe and accurate tool for the preoperative diagnosis of metastatic spread to the paraesophageal and celiac lymph nodes. EUS-FNA is also increasingly recognized as an accurate, cost-effective and safe means of evaluating and staging patients with lung cancer. EUS-FNA is useful in providing tissue confirmation of cancer in cases in which bronchoscopy or computed tomography-guided approaches has been non-diagnostic. EUS-guided therapies are paving the way for therapeutic/interventional EUS. The interventional endoscopist will now play a more central role in the diagnosis and treatment of various gastrointestinal malignancies by delivering antitumor agents.

Staging of esophageal cancer by EUS: staging accuracy revisited

BACKGROUND

EUS plays an important role in the preoperative staging of esophageal cancer. Recent data have called into question the staging accuracy of EUS, particularly in patients with early disease.

OBJECTIVE

Our goals were to assess our institution's EUS staging accuracy by experienced endosonographers in a contemporary cohort of patients encompassing a wide range of disease stages and to assess staging accuracy after dilation of malignant strictures.

DESIGN

Retrospective data review.

SETTING

Single tertiary care center.

PATIENTS AND INTERVENTIONS

A total of 42 patients with esophageal cancer undergoing preoperative EUS staging without neoadjuvant chemoradiotherapy between December 1999 and December 2004 were evaluated.

MAIN OUTCOME MEASUREMENTS

EUS T and N stage sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.

RESULTS

EUS accurately predicted T stage in 76% of cases and N stage in 89% of cases. Staging accuracy for T3 versus T1 and T2 disease and for N0 versus N1 disease was not significantly different. In 11 cases, malignant strictures required dilation, with 6 tumors being passable post dilation. Post dilation, T staging accuracy was 80% in impassable tumors and 100% in passable tumors, and N staging accuracy was 100% in the passable tumors.

LIMITATIONS

Relatively small number of patients.

CONCLUSIONS

EUS accurately predicts T and N stage in patients with a range of disease stages. EUS provides good staging accuracy after dilation of malignant strictures regardless of whether full tumor traversal post dilation is possible.

Significance of neoplastic involvement of margins obtained by endoscopic mucosal resection in Barrett's esophagus

OBJECTIVES

Although EMR has been used for elimination of neoplasia in BE, the significance of positive carcinoma margins and depth of invasion on endoscopic resection pathology has not been assessed using a valid standard. The aim of this study was to assess the accuracy of tumor staging by EMR using esophagectomy as the standard.

METHODS

Medical records of patients, who underwent endoscopic resection for esophageal carcinoma or high-grade dysplasia in BE followed by esophagectomy, were reviewed. Data were abstracted from a prospectively maintained EMR database. Endosonography and endoscopic resection were performed by a single experienced endoscopist. Two experienced GI pathologists interpreted all histological results. Standard statistical tests were used to compare continuous and categorical variables.

RESULTS

Twenty-five patients were included in the study. Three patients had mucosal carcinoma and 16 had submucosal carcinoma following endoscopic resection. Surgical pathology staging was consistent with preoperative EMR staging in all patients. No patient with negative mucosal resection margins had residual tumor at the resection site at esophagectomy. In patients with submucosal carcinoma, 8 had residual carcinoma at the EMR site at surgery and 5 patients had metastatic lymphadenopathy.

CONCLUSIONS

Tumor staging using EMR pathology is accurate when compared with surgical pathology following esophagectomy. Negative margins on EMR pathology correlate with absence of residual disease at the EMR site at esophagectomy. Submucosal carcinoma on EMR specimens was associated with a high prevalence of residual disease at surgery (50%) and metastatic lymphadenopathy (31%).

T2N0M0 esophageal cancer

OBJECTIVE

The study objective was to develop a treatment algorithm for cT2N0M0 esophageal cancer by determining (1) errors in clinical staging and (2) consequences of overtreatment and undertreatment of incorrectly clinically staged patients.

METHODS

Of 742 clinically staged patients, 61 (8.2%) had cT2N0M0 cancer; 45 underwent surgery alone; 8 underwent surgery and postoperative adjuvant therapy; and 8 underwent induction therapy, then surgery. As reference, 31 of 666 patients (4.7%) who underwent surgery first had pT2N0M0 cancer and a 5-year survival of 61% +/- 9.3%. Referent values were calculated from 445 clinically staged patients who underwent surgery first. Unmatched and matched survival comparisons were made using the log-rank test.

RESULTS

Only 7 of 53 cT2N0M0 cancers treated with surgery first were pT2N0M0 (13% positive predictive value). Of incorrectly staged cT2N0M0 cancers (46/53), 29 (63%) were overstaged and 17 (37%) were understaged. Most overstaged cancers were pT1 (11 [38%] T1a and 15 [52%] T1b), and most understaged cancers were pN1 (13 [76%]). Matched overstaged patients treated by surgery alone (25/28) had a 5-year survival similar to that of patients with pTNM (69% +/- 9.8% vs 63% +/- 13%, P =.8). Understaged patients did better at 5 years than patients with pTNM if they had postoperative adjuvant therapy, not surgery alone (43% +/- 22% vs 10% +/- 9.5%, P = .17). Induction therapy decreased 5-year survival compared with all other treatment strategies (13% +/- 12% vs 52% +/- 7.4%, P =.05).

CONCLUSIONS

Patients with cT2N0M0 cancers should undergo surgery first with lymphadenectomy. Clinically understaged patients should receive postoperative adjuvant therapy. In the unlikely event that patients with cT2N0M0 cancers are found to have an uncommon pT2N0M0 cancer, they will have acceptable survival with surgery alone.

Diagnosis and therapy in advanced cancer of the esophagus and the gastroesophageal junction

PURPOSE OF REVIEW

The aim of this article is to discuss recent developments in the diagnosis and treatment with curative option of advanced cancer of the esophagus and gastroesophageal junction.

RECENT FINDINGS

Recent data indicate improvement of clinical staging accuracy by multi-slice computer tomography, endoscopic ultrasound with fine needle aspiration and positron emission tomography, the latter gaining growing impact as a prognostic indicator. When combined with extended lymphadenectomy primary surgery offers 5-year survivals between 25 and 35% for stage III disease. Results of induction therapy remain conflicting. While the most recent meta-analysis favored induction chemoradiotherapy, a subsequent randomized trial failed to confirm this conclusion. A growing interest in adjuvant chemoradiotherapy is stimulated by promising results from a recent pilot study. Trials investigating definitive chemoradiotherapy indicate a high incidence of locoregional recurrence. The emerging understanding of the molecular pathways that govern neoplastic events are under intense investigation. Results of pilot clinical studies on targeted therapy are expected shortly.

SUMMARY

Refinements in staging offer incremental increase of accuracy, the impact of positron emission tomography becoming increasingly important. In locally advanced disease, the debate on the added value of multimodality therapy remains unsolved as primary surgery combined with extended lymphadenectomy offers equal results. New drugs in particular in combination with targeted therapy may offer better perspectives in the near future.

[Mucosectomy as sufficient therapy for early squamous cell]

Squamous cell carcinoma of the esophagus can be treated endoscopically under certain conditions. A carcinoma (T1a) limited to the mucosa with a low infiltration depth (m1-m2) and limited extent (< or =2 cm) can be removed by electrical snare with no risk of lymph node metastasis. Due to the increased risk of lymphatic spread, deeply infiltrating submucosal tumours (sm2-sm3) must be treated by surgical resection. Endoscopic resection (mucosectomy) is performed by electric snare and the cap method, additionally with APC coagulation or photodynamic therapy. Multifocal tumour growth and incomplete resection are both risk factors for local recurrence. If the strict conditions for endoscopic resection are fulfilled, the 5-year survival time of these patients with early cancer is no different from that of the population as a whole.

Tumor length as a prognostic factor in esophageal malignancy: univariate and multivariate survival analyses

BACKGROUND AND OBJECTIVES

Gastrointestinal specialists generally feel that long esophageal tumors carry a worse prognosis and are likely to be more advanced than shorter lesions. Our aim was to investigate the relationship between histologically determined tumor length and aspects of tumor pathology and survival for patients with resected esophageal malignancy.

METHODS

Three hundred and nine patients who underwent esophageal resection with curative intent in our unit between 1994 and 2003 were retrospectively analyzed. Pathological details such as TNM stage, differentiation, completeness of surgical resection, and overall stage were collected. Survival data were obtained for each patient and univariate and multivariate analyses were performed. Overall survival was used as the primary endpoint.

RESULTS

There were 225 adenocarcinomas, 72 squamous cell carcinomas, and 12 other tumor types with a median tumor length of 3.5 cm (range 0.5-14 cm). Tumor length greater than 3.5 cm was associated with increasing T stage (P = 0.0001), N stage (P = 0.032), overall stage (P = 0.003), and involvement of the longitudinal resection margins (P = 0.02). Univariate analysis found tumor length greater than 3.5 cm was associated with worse overall survival compared with shorter tumors (P = 0.0002). Tumor length remained a significant prognostic factor on multivariate analysis (P = 0.04). Other prognostic factors on multivariate analysis were age, tumor differentiation, nodal involvement, and resection margin status.

CONCLUSION

Tumor length greater than 3.5 cm (as determined histologically) is associated with worse disease stage and poor overall patient survival. If preoperative endoscopic tumor length bears a similar relationship, this could assist in patient selection for appropriate treatments.

Endoscopic mucosal resection

Endoscopic mucosal resection (EMR) is a promising therapeutic option for removal of superficial carcinomas or premalignant lesions throughout the gastrointestinal tract. This review discusses indications and the several techniques of EMR in early tumors of esophagus, stomach, duodenum, and colon. EMR is not yet widely utilized in the West. However, great benefits may be obtained from this non-invasive technique after an accurate evaluation of patients and a careful staging of lesions that may assess the depth of infiltration and exclude the presence of lymph node metastases. EMR permits a complete removal of the lesion with histologic assessment of the entire specimen and the change in the pathologic stage in a significant number of patients. To minimize the risk of serious complications (mostly bleeding and perforation), only experienced endoscopists should undertake EMR in an appropriate environment. Data from literature are encouraging on the use of EMR, but a long-term follow-up of a large number of patients is necessary to confirm the effectiveness of this therapy.

Frozen section analysis of esophageal endoscopic mucosal resection specimens in the real-time management of Barrett's esophagus

BACKGROUND & AIMS

The aim of this study was to assess the validity of frozen section analysis of endoscopic mucosal resection (EMR) specimens from Barrett's esophagus as compared with permanent sections for the detection of neoplasia. Frozen sections help to give immediate feedback for surgical procedures. It has not been determined whether EMR can be adequately interpreted by using frozen sections to aid endoscopists in completely resecting neoplastic lesions.

METHODS

EMR specimens from Barrett's esophagus with high-grade dysplasia (HGD) and/or carcinoma were tested by frozen section. Pathologists evaluated EMR specimens for the depth of invasion as well as the appearance of clear margins of resection. The kappa statistic was calculated to assess the degree of agreement between the frozen section and permanent section diagnoses.

RESULTS

Twenty-three consecutive patients underwent 30 EMRs with frozen section diagnosis. Frozen section revealed a carcinoma in 7 specimens (23%) and dysplasia in 20 (66%). Permanent sections found carcinoma in 8 specimens (26%), dysplasia in 19 specimens (63%), and normal or nondysplastic Barrett's esophagus in the remainder. The kappa statistic for the depth of invasion of EMR specimens was 0.93 (near perfect agreement). The kappa statistic for the margins of the EMR specimens was 0.80 (excellent agreement).

CONCLUSIONS

This study indicated that frozen section analysis of esophageal EMR specimens is valid as compared with permanent section. This technique might allow rapid evaluation about the degree and depth of involvement of cancers. This allows physicians to make decisions regarding further therapy if margins are involved or decrease the use of EMR for histologically benign-appearing lesions.

Acoustic radiation force impulse (ARFI) imaging of the gastrointestinal tract

The evaluation of lesions in the gastrointestinal (GI) tract using ultrasound can suffer from poor contrast between healthy and diseased tissue. Acoustic Radiation Force Impulse (ARFI) imaging provides information about the mechanical properties of tissue using brief, high-intensity, focused ultrasound to generate radiation force and ultrasonic correlation-based methods to track the resulting tissue displacement. Using conventional linear arrays, ARFI imaging has shown improved contrast over B-mode images when applied to solid masses in the breast and liver. The purpose of this work is to (1) investigate the potential for ARFI imaging to provide improvements over conventional B-mode imaging of GI lesions and (2) demonstrate that ARFI imaging can be performed with an endocavity probe. ARFI images of an adenocarcinoma of the gastroesophageal (GE) junction, status-post chemotherapy and radiation treatment, demonstrate better contrast between healthy and fibrotic/malignant tissue than standard B-mode images. ARFI images of healthy gastric, esophageal, and colonic tissue specimens differentiate normal anatomic tissue layers (i.e., mucosal, muscularis and adventitial layers), as confirmed by histologic evaluation. ARFI imaging of ex vivo colon and small bowel tumors portray interesting contrast and structure that are not as well defined in B-mode images. An endocavity probe created ARFI images to a depth of over 2 cm in tissue-mimicking phantoms, with maximum displacements of 4 microm. These findings support the clinical feasibility of endocavity ARFI imaging to guide diagnosis and staging of disease processes in the GI tract.