A prospective evaluation of catheter probe EUS for the detection of ascites in patients with gastric carcinoma

Current and future imaging modalities in gastric cancer

Gastric adenocarcinoma treatment can include endoscopic mucosal resection, surgery, chemotherapy, radiation, and palliative measures depending on staging. Both invasive and noninvasive staging techniques have been used to dictate the best treatment pathway. Here, we review the current imaging modalities used in gastric cancer as well as novel techniques to accurately stage and screen these patients.

Imaging strategies in the management of gastric cancer: current role and future potential of MRI

Accurate preoperative staging of gastric cancer and the assessment of tumor response to neoadjuvant treatment is of importance for treatment and prognosis. Current imaging techniques, mainly endoscopic ultrasonography (EUS), computed tomography (CT) and ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET), have their limitations. Historically, the role of magnetic resonance imaging (MRI) in gastric cancer has been limited, but with the continuous technical improvements, MRI has become a more potent imaging technique for gastrointestinal malignancies. The accuracy of MRI for T- and N-staging of gastric cancer is similar to EUS and CT, making MRI a suitable alternative to other imaging strategies. There is limited evidence on the performance of MRI for M-staging of gastric cancer specifically, but MRI is widely used for diagnosing liver metastases and shows potential for diagnosing peritoneal seeding. Recent pilot studies showed that treatment response assessment as well as detection of lymph node metastases and systemic disease might benefit from functional MRI (e.g. diffusion weighted imaging and dynamic contrast enhancement). Regarding treatment guidance, additional value of MRI might be expected from its role in better defining clinical target volumes and setup verification with MR-guided radiation treatment.

Gastric carcinoma: imaging diagnosis, staging and assessment of treatment response

Gastric carcinoma (GC) is one of the most common causes of cancer-related death worldwide. Surgical resection is the only cure available and is dependent on the GC stage at presentation, which incorporates depth of tumor invasion, extent of lymph node and distant metastases. Accurate preoperative staging is therefore essential for optimal surgical management with consideration of preoperative and/or postoperative chemotherapy. Multidetector computed tomography (MDCT) with its ability to assess tumor depth, nodal disease and metastases is the preferred technique for staging GC. Endoscopic ultrasonography is more accurate for assessing the depth of wall invasion in early cancer, but is limited in the assessment of advanced local or stenotic cancer and detection of distant metastases. Magnetic resonance imaging (MRI), although useful for staging, is not proven to be effective. Positron emission tomography (PET) is most useful for detecting and characterizing distant metastases. Both MDCT and PET are useful for assessment of treatment response following preoperative chemotherapy and for detection of recurrence after surgical resection. This review article discusses the usefulness of imaging modalities for detecting, staging and assessing treatment response for GC and the potential role of newer applications including CT volumetry, virtual gastroscopy and perfusion CT in the management of GC.

[Significance of free perigastric fluid detected by echoendoscopy in patients with gastric cancer]

OBJECTIVES

To determine the diagnostic value of free perigastric fluid identified by echoendoscopy in patients with gastric cancer and to establish the factors related to the presence of peritoneal carcinomatosis in these patients.

MATERIAL AND METHODS

We retrospectively included 100 patients with a histological diagnosis of gastric adenocarcinoma referred for echoendoscopy. A positive result was defined as the echoendoscopic identification of free perigastric fluid. This result was compared with the final study based on exploratory laparoscopy-laparotomy. The histological and endoscopic characteristics were compared with the final result.

RESULTS

Free perigastric fluid was found in 21 patients (21%). Among these, 15 (71%) showed peritoneal carcinomatosis, confirmed by laparoscopy (12 patients) or echoendoscopy-guided fine-needle-aspiration biopsy (three patients). In seven of the 79 patients (8%) not showing the presence of ascites, peritoneal implants were identified by exploratory laparoscopy-laparotomy. The sensitivity, specificity, positive predictive value and diagnostic accuracy of free fluid in the diagnosis of carcinomatosis was 68%, 92%, 71%, 91% and 87%, respectively. No histologic or endoscopic factors related to the malignancy of echoendoscopically-detected fluid were identified.

CONCLUSION

In patients with gastric cancer, free perigastric fluid identified by echoendoscopy is an important predictive factor of peritoneal carcinomatosis and may have significant implications in the management of these patients.

Prognostic significance of computed tomography defined ascites in advanced gastric cancer

PURPOSE

The aim of this study was to investigate the clinicopathologic features and prognosis in patients with computed tomography (CT) findings of ascites, with a focus on the correlation with peritoneal carcinomatosis.

METHODS

This study included a total of 157 patients who underwent surgery for advanced gastric cancer from 2003 to 2008 at the Department of Surgery, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea, which were analyzed retrospectively.

RESULTS

Fourteen patients (8.9%) presented ascites on their CT scan. Among them, 10 patients had peritoneal carcinomatosis, and showed significant difference with CT ascites positive group in the incidence of peritoneal carcinomatosis. The presence of CT ascites was significantly correlated with pathologic T stage, tumor size, histologic type, CT T and N stages, CT peritoneal nodularity and curability of surgery, statistically. The prognosis of CT ascites positive group was much poorer in the total advanced gastric cancer patients (P < 0.001), as well as in patients with pathologic T4 (P = 0.002). Also in patients without peritoneal carcinomatosis, CT ascites positive subgroup tended to have a worse prognosis than CT ascites negative subgroup (P = 0.086). Tumor size, CT T and N stages and the presence of CT peritoneal nodularity and ascites influenced the prognosis significantly; among which, if a tumor size larger than 5 cm, CT T4 stage and the presence of CT ascites were identified as independent prognostic factors.

CONCLUSION

The presence of ascites was closely associated with peritoneal metastasis, and was the most significant independent prognostic factor in advanced gastric cancer in the present study.

Imaging in assessing hepatic and peritoneal metastases of gastric cancer: a systematic review

BACKGROUND

Hepatic and peritoneal metastases of gastric cancer are operation contraindications. Systematic review to provide an overview of imaging in predicting the status of liver and peritoneum pre-therapeutically is essential.

METHODS

A systematic review of relevant literatures was performed in Pubmed/Medline, Embase, The Cochrane Library and the China Biological Medicine Databases. QUADAS was used for assessing the methodological quality of included studies and the bivariate model was used for this meta-analysis.

RESULTS

Totally 33 studies were included (8 US studies, 5 EUS studies, 22 CT studies, 2 MRI studies and 5 18F-FDG PET studies) and the methodological quality of included studies was moderate. The result of meta-analysis showed that CT is the most sensitive imaging method [0.74 (95% CI: 0.59-0.85)] with a high rate of specificity [0.99 (95% CI: 0.97-1.00)] in detecting hepatic metastasis, and EUS is the most sensitive imaging modality [0.34 (95% CI: 0.10-0.69) ] with a specificity of 0.96 (95% CI: 0.87-0.99) in detecting peritoneal metastasis. Only two eligible MRI studies were identified and the data were not combined. The two studies found that MRI had both high sensitivity and specificity in detecting liver metastasis.

CONCLUSION

US, EUS, CT and 18F-FDG PET did not obtain consistently high sensitivity and specificity in assessing liver and peritoneal metastases of gastric cancer. The value of laparoscopy, PET/CT, DW-MRI, and new PET tracers such as 18F-FLT needs to be studied in future.

[Diagnostic imaging in oncology--evidence reviews for evidence based guidelines by the Agency of Quality for Medicine (ÄZQ)]

Within the context of the development of evidence-based oncology guidelines, the Agency for Quality in Medicine undertook evidence reviews for diagnostic imaging procedures. Systematic searches retrieved no randomised controlled trials, but only cohort studies and case series of mostly moderate quality. The identified studies provided only a restricted basis for the guideline recommendations as their validity was limited and only outcomes of diagnostic accuracy were examined. However, decision criteria for recommending diagnostic strategies significantly comprise judgements about required resources and availability of diagnostic imaging procedures. These criteria as well as patient out-comes were mostly implicit and should be explicated in future. In order to increase the relevance of evidence reviews for oncological diagnosis, high quality studies which examine resources and patient-centred outcomes for diagnostic strategies are required.

Survival in patients with pancreatic cancer after the diagnosis of malignant ascites or liver metastases by EUS-FNA

BACKGROUND

The expected survival after the EUS-FNA diagnosis of malignant ascites or liver metastases from pancreatic cancer is not known.

OBJECTIVE

To report overall and 1-year survival in these patients.

DESIGN

Retrospective cohort series.

SETTING

Tertiary referral hospital.

PATIENTS

Consecutive subjects with newly diagnosed pancreatic cancer from June 1998 and March 2008 in whom EUS-FNA of the liver or ascitic fluid confirmed hepatic metastases or malignant ascites.

INTERVENTIONS

Calculation of survival after diagnosis by using the Social Security Death Index.

MAIN OUTCOME MEASUREMENTS

Survival after EUS-FNA diagnosis of stage IV pancreatic cancer.

RESULTS

EUS-FNA identified liver metastases and malignant ascites from primary pancreatic cancer in 75 and 13 patients, respectively, and all 88 died during follow-up. For all 88 patients, the 1-year survival rate and median survival were 3.4% (95% CI, 1.1%-10.4%) and 82 days (range 2-754 days), respectively. The 1-year survival rates for those with liver metastases (4.0% [95% CI, 1.3%-12.1%]) and for those with malignant ascites (0% [95% CI, 0-24.7%]) were similar (P = 1.0). The median survival for patients with liver metastases of 83 days (range 2-754 days) was similar to that for those with malignant ascites (64 days; range 2-153 days) (P = .13). No clinical variable considered predicted survival of more than, less than, or 3 months.

LIMITATIONS

Retrospective series with variable treatment for malignancy.

CONCLUSIONS

In patients with pancreatic cancer, identification of malignant ascites or liver metastases by EUS-FNA is associated with a very poor prognosis.

[I Brazilian consensus of endoscopic ultrasonography]

BACKGROUND

In the last 20 years, several papers have focused on demonstrating the impact of endoscopic ultrasonography findings on the management of different clinical scenarios in digestive disease. This fact is an indirect evidence of the difficulty of popularization of the method. On other hand, the limited availability of endoscopic ultrasonography in Brazil is a direct evidence of this limitation. This was the rationale for the organization of a consensus meeting on endoscopic ultrasonography. It was aimed to identify the best evidence that support the use of endoscopic ultrasonography in gastroenterology.

METHODS

A panel of experts on endoscopic ultrasonography was selected based on the files of the Gastroenterology and Endoscopy Societies and on the registries of endoscope manufacturers. Two members of the meeting selected the relevant topics that were transformed into questions. The topics and the questions were debated among the experts five months before the consensus meeting. The experts were asked to perform systematic reviews in order to answer the questions so it could be possible to grade the answers based on the strength of the evidence. During the two days of the meeting the answers were presented, debated and voted. Consensus was reached when a minimum of 70% of the voters were in agreement. The final consensus report was submitted to the experts' evaluation and approval.

RESULTS

Seventy nine questions were debated by the experts at the pre-Consensus meeting. As the result of this debate 85 questions came out and were assigned to the members of the panel. During the Consensus meeting 22 experts debated and voted 85 answers. Consensus was reached for several clinical scenarios for which the impact of endoscopic ultrasonography findings were supported by level 1 evidences: differential diagnosis of subepithelial lesions and thickening of gastric folds, staging and diagnosis of unresectable esophageal cancer, indirect signs of peritoneal involvement of gastric cancer, MALT gastric lymphoma and rectal cancer staging, diagnosis of common bile duct and gallbladder stones, diagnosis of chronic pancreatitis and differential diagnosis of a solid mass in chronic pancreatitis, differential diagnosis of the pancreatic cyst, prediction of the results of the endoscopic treatment of esophageal varices and diagnosis and staging of non-small cell lung cancer.

CONCLUSIONS

There are the highest levels of evidences that support the indication of endoscopic ultrasonography for several digestive diseases and even for non-small cell lung cancer.

Endoscopic ultrasonography-detected low-volume ascites as a predictor of inoperability for oesophagogastric cancer

Background

Endoscopic ultrasonography (EUS) can detect low-volume ascites (LVA) not apparent on computed tomography. The aim of this study was to assess the importance of LVA for management of patients with oesophagogastric (OG) cancer.

Methods

Patients with LVA were identified from a prospective OG cancer unit database between January 2002 and January 2006.

Results

Of 1118 patients staged with OG cancer, 802 had EUS. The incidence of LVA was 8·4 per cent overall but fell to 6·5 per cent when those with metastases on computed tomography were excluded. Only patients with gastric and OG junction carcinoma had LVA. Staging laparoscopy in the 21 patients with LVA revealed that 11 (52 per cent) were inoperable. The remainder had laparotomy and complete (R0) resection was possible in only five (50 per cent). In 106 patients who had staging laparoscopy after EUS without LVA, 37 (34·9 per cent) were inoperable and 56 of the remaining 69 (81 per cent) had R0 resection.

Conclusion

The presence of LVA on EUS is uncommon in patients with OG cancer but very important, being indicative of incurable disease in 76 per cent. This information will be helpful in counselling patients regarding management options and the low likelihood of potentially curative treatment.

Endoscopic ultrasound-guided fine-needle aspiration of ascites

BACKGROUND & AIMS

The aim of this study is to report a large single-center experience with endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) of ascites.

METHODS

Consecutive patients at our institution in whom EUS-guided paracentesis was performed between January 1997 and July 2005 were identified retrospectively. All procedures were performed by or under the supervision of 1 of 5 experienced endosonographers with available on-site cytopathology.

RESULTS

Sixty consecutive patients (33 men; mean age, 67 y) were identified. Previously attempted percutaneous paracentesis was unsuccessful in 3 of 6 patients. Ascites confirmed by EUS FNA was visible in 28 of 54 (52%) computerized tomography, 3 of 11 (27%) transabdominal ultrasound, and 4 of 8 (50%) magnetic resonance imaging examinations before EUS. Transgastric (n = 55) or transduodenal (n = 5) EUS-guided paracentesis (mean, 8.9; range, 1-40 mL) revealed malignancy in 16 (27%) from primary pancreatic (n = 9), gastric (n = 2), urothelial (n = 1), esophageal (n = 1), gallbladder (n = 1), bile duct (n = 1) cancer, and lymphoma (n = 1). The cytology from 2 patients was atypical (1 suspicious for malignancy and 1 considered reactive) and the remaining 42 were benign. Potential complications occurred in 2 of 60 (3%) patients with self-limited fever. Of the 8 of 60 (13%) patients who underwent subsequent surgery, 3 had metastatic pancreatic adenocarcinoma (n = 2) and metastatic small intestinal carcinoid (n = 1) to the peritoneum after negative EUS-FNA cytology.

CONCLUSIONS

EUS frequently identifies ascites missed by other imaging studies. EUS-guided paracentesis may identify malignancy in a subset of patients. Negative ascitic fluid cytology from EUS FNA does not exclude possible peritoneal carcinomatosis.

Accuracy of endoscopic ultrasound staging of gastric cancer in routine clinical practice in Singapore

OBJECTIVE

Endoscopic ultrasound has emerged as the leading modality to assess the T and N stage in gastric cancer. This study aimed to assess the accuracy of TN staging by endoscopic ultrasound in routine clinical practice in Singapore.

METHODS

Over a period of 7 years, 77 patients (male: 70%; median age 62.8 years) with gastric cancer underwent preoperative staging with endoscopic ultrasound. Fifty-seven patients eventually underwent surgery with tissues available for histopathological staging and comparison.

RESULTS

The tumor locations were: cardia: 13; corpus: 20; incisura: 19; antrum: 25. The majority was poorly differentiated (57.1%); 26% were moderately differentiated and 16.9% were well differentiated adenocarcinoma. Compared to pathological staging, the overall accuracy of T staging by endoscopic ultrasound was 77.2% (17.5% under-staged: 5.3% over-staged). The staging accuracy of T1 (92.9%) and T3 (81.8%) was higher than T2 (57.1%) and T4. For N staging, the accuracy of endoscopic ultrasound was 59.6% (26.3% under-staged; 14% over-staged); this was significantly superior to computer tomography (43.9%).

CONCLUSION

Endoscopic ultrasound is useful for the T staging of gastric cancer, with an overall accuracy rate of 77%, and up to 93% for T1 lesions. Under-staging may occur due to microscopic tumor infiltration, while over-staging may arise due to inflammatory reactions. The accuracy of N staging is lower at 60%, but could be further improved with the use of fine needle aspiration.

Endoscopic ultrasonography for gastric cancer: does it influence treatment?

BACKGROUND

This study aimed to evaluate the utility and shortcomings of endoscopic ultrasound (EUS) in tumor node metastasis (TNM) staging of gastric cancer and its influence on treatment.

METHODS

The series included 126 patients (65 men and 44 women) with gastric cancer who underwent EUS from July 1997 to June 2003 at the National University Hospital, Singapore. The final analysis included 109 patients ranging in age from 29 to 97 years (mean, 63.13 years).

RESULTS

EUS staging for primary disease: Specimen histology was available for 102 of the 109 patients who underwent surgery. The accuracy was 79% for T1, 73.9% for T2, 85.7% for T3, and 72.7% for T4. The overall accuracy was 80.4%. EUS staging for nodes: The sensitivity of EUS for detecting nodal disease was 74.2% for N0, 78% for N1, 53.8% for N2, and 50% for N3. Overall, the N staging by EUS showed a sensitivity of 82.8%, a specificity of 74.2%, a positive predictive value of 85.4%, a negative predictive value of 70.2%, and an accuracy of 77.7%. Radical gastrectomy was proposed for 95 patients on the basis of the staging with EUS and computed tomography (CT) scan, and 87 patients (91.6%) underwent the surgery. Preoperative staging accurately predicted the operative strategy for 89% of the patients. No significant predictor for accuracy was achieved by performing a logistic regression analysis for the correct staging of T stage using EUS and adjusting for tumor location (middle part/distal third/whole stomach vs proximal/cardioesophageal) (p = 0.873), operator (p = 0.546), and subject's sequence (initial 50 vs last 50 cases) (p = 0.06).

CONCLUSION

Ultrasound is the most accurate and reliable method for the preoperative staging of gastric carcinomas, and it is mandatory if a tailored therapeutic approach is planned according to stage.

Usefulness of endoscopic ultrasonography in preoperative TNM staging of gastric cancer

AIM: To evaluate the value of endoscopic ultrasono-graphy (EUS) in the preoperative TNM staging of gastric cancer.

METHODS: Forty-one patients with gastric cancer (12 early stage and 29 advanced stage) proved by esophagogastroduodenoscopy and biopsies preoperatively evaluated with EUS according to TNM (1997) classification of International Union Contrele Cancer (UICC). Pentax EG-3630U/Hitachi EUB-525 echo endoscope with real-time ultrasound imaging linear scanning transducers (7.5 and 5.0 MHz) and Doppler information was used in the current study. EUS staging procedures for tumor depth of invasion (T stage) were performed according to the widely accepted five-layer structure of the gastric wall. All patients underwent surgery. Diagnostic accuracy of EUS for TNM staging of gastric cancer was determined by comparing preoperative EUS with subsequent postoperative histopathologic findings.

RESULTS: The overall diagnostic accuracy of EUS in preoperative determination of cancer depth of invasion was 68.3% (41/28) and 83.3% (12/10), 60% (20/12), 100% (5/5), 25% (4/1) for T1, T2, T3, and T4, respectively. The rates for overstaging and understaging were 24.4% (41/10), and 7.3% (41/3), respectively. EUS tended to overstage T criteria, and main reasons for overstaging were thickening of the gastric wall due to perifocal inflammatory change, and absence of serosal layer in certain areas of the stomach. The diagnostic accuracy of metastatic lymph node involvement or N staging of EUS was 100% (17/17) for N0 and 41.7% (24/10) for N+, respectively, and 66% (41/27) overall. Misdiagnosing of the metastatic lymph nodes was related to the difficulty of distinguishing inflammatory lymph nodes from malignant lymph nodes, which imitate similar echo features. Predominant location and distribution of tumors in the stomach were in the antrum (20 patients), and the lesser curvature (17 patients), respectively. Three cases were found as surgically unresectable (T4 N+), and included as being correctly diagnosed by EUS.

CONCLUSION: EUS is a useful diagnostic method for preoperative staging of gastric cancer for T and N criteria. However, EUS evaluation of malignant lymph nodes is still unsatisfactory.

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Technology Insight: current status of endoscopic ultrasonography

Endoscopic ultrasound (EUS) has become the most accurate imaging modality for locoregional cancer staging of the gastrointestinal tract. Fine-needle aspiration (FNA) has added a new level of accuracy for EUS in nodal staging, with reported numbers in the 90% range for luminal and pancreaticobiliary disease. In addition, new non-gastrointestinal applications are being evaluated, such as the role of EUS-FNA for the staging of non-small-cell lung cancer and exploration of the posterior mediastinum. Furthermore, the same techniques that make safe tissue sampling possible are being explored for their use as interventional applications, such as EUS-guided celiac plexus neurolysis, fine-needle injection, EUS-guided pseudocyst drainage, and EUS-guided cholangiography and pancreatography. This review describes the current clinical status of EUS in gastrointestinal oncology, as well as future and novel indications and therapeutic strategies for this technology.