Hydro-dynamic CT preoperative staging of gastric cancer: correlation with pathological findings. A prospective study of 107 cases

Value of orthogonal axial MR images in preoperative T staging of gastric cancer

PURPOSE

To assess the value of orthogonal axial images (OAI) of MRI in gastric cancer T staging.

METHODS

This retrospective study enrolled 133 patients (median age, 63 [range, 24-85] years) with gastric adenocarcinoma who underwent both CT and MRI followed by surgery. MRI lacking or incorporating OAI and CT images were evaluated, respectively. Diagnostic performance (accuracy, sensitivity, and specificity) for each T stage, overall diagnostic accuracy and rates of over- and understaging were quantified employing pathological T stage as a reference standard. The McNemar's test was performed to compare the overall accuracy.

RESULTS

Among patients with pT1-pT4 disease, MRI with OAI (accuracy: 88.7-94.7%, sensitivity: 66.7-93.0%, specificity: 91.5-100.0%) exhibited superior diagnostic performance compared to MRI without OAI (accuracy: 81.2-88.7%, sensitivity: 46.2-83.1%, specificity: 85.5-99.1%) and CT (accuracy: 88.0-92.5%, sensitivity: 53.3-90.1%, specificity: 88.7-98.1%). The overall accuracy of MRI with OAI was significantly higher (83.5%) than that of MRI without OAI (67.7%) (p < .001). However, there was no significant difference in the overall accuracy of MRI with OAI and CT (78.9%) (p = .35). The over- and understaging rates of MRI with OAI (12.0, 4.5%) were lower than those of MRI without OAI (21.8, 10.5%) and CT (12.8, 8.3%).

CONCLUSION

OAI play a pivotal role in the T staging of gastric cancer. MRI incorporating OAI demonstrated commendable performance for gastric cancer T-staging, with a slight tendency toward its superiority over CT.

Advanced Gastric Cancer: CT Radiomics Prediction of Lymph Modes Metastasis After Neoadjuvant Chemotherapy

This study aims to create and assess machine learning models for predicting lymph node metastases following neoadjuvant treatment in advanced gastric cancer (AGC) using baseline and restaging computed tomography (CT). We evaluated CT images and pathological data from 158 patients with resected stomach cancer from two institutions in this retrospective analysis. Patients were eligible for inclusion if they had histologically proven gastric cancer. They had received neoadjuvant chemotherapy, with at least 15 lymph nodes removed. All patients received baseline and preoperative abdominal CT and had complete clinicopathological reports. They were divided into two cohorts: (a) the primary cohort (n = 125) for model creation and (b) the testing cohort (n = 33) for evaluating models' capacity to predict the existence of lymph node metastases. The diagnostic ability of the radiomics-model for lymph node metastasis was compared to traditional CT morphological diagnosis by radiologist. The radiomics model based on the baseline and preoperative CT images produced encouraging results in the training group (AUC 0.846) and testing cohort (AUC 0.843). In the training cohort, the sensitivity and specificity were 81.3% and 77.8%, respectively, whereas in the testing cohort, they were 84% and 75%. The diagnostic sensitivity and specificity of the radiologist were 70% and 42.2% (using baseline CT) and 46.3% and 62.2% (using preoperative CT). In particular, the specificity of radiomics model was higher than that of conventional CT in diagnosing N0 cases (no lymph node metastasis). The CT-based radiomics model could assess lymph node metastasis more accurately than traditional CT imaging in AGC patients following neoadjuvant chemotherapy.

Accuracy of 18F-FDG PET/CT and CECT for primary staging and diagnosis of recurrent gastric cancer: A meta-analysis

Contrast-enhanced computed tomography (CECT) is commonly used for staging and diagnosing recurrent gastric cancer. Recently, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT gained popularity as a diagnostic tool owing to advantages including dual functional and anatomical imaging, which may facilitate early diagnosis. The diagnostic performance of 18F-FDG PET/CT and CECT has been assessed in several studies but with variable results. Therefore, the present meta-analysis aimed to evaluate the accuracy of 18F-FDG PET/CT and CECT for primary TNM staging and the diagnosis of recurrent gastric cancers. A systematic search of the PubMed Central, Medline, Scopus, Cochrane and Embase databases from inception until January 2020 was performed. The Quality Assessment of Diagnostic Accuracy Study-2 tool was used to determine the quality of the selected studies. Pooled estimates of sensitivity and specificity were calculated. A total of 58 studies comprising 9,997 patients were included. Most studies had a low risk of bias. The sensitivity and specificity for nodal staging of gastric cancer were 49% (95% CI, 37-61%) and 92% (95% CI, 86-96%) for 18F-FDG PET/CT, respectively, and 67% (95% CI, 57-76%) and 86% (95% CI, 81-89%) for CECT, respectively. For metastasis staging, the sensitivity and specificity were 56% (95% CI, 40-71%) and 97% (95% CI, 87-99%) for 18F-FDG PET/CT, respectively, and 59% (95% CI, 41-75%) and 96% (95% CI, 83-99%) for CECT, respectively. For diagnosing cancer recurrence, the pooled sensitivity and specificity were 81% (95% CI, 72-88%) and 83% (95% CI, 74-89%) for 18F-FDG PET/CT, respectively, and 59% (95% CI, 41-75%) and 96% (95% CI, 83-99%) for CECT, respectively. Both 18F-FDG PET/CT and CECT were deemed highly useful for diagnosing recurrent gastric cancer due to their high sensitivities and specificities. However, these techniques cannot be used to exclude or confirm the presence of lymph node metastases or recurrent gastric cancer tumors, but can be used for the confirmation of distal metastasis.

Regional Lymph Node Dissection as an Additional Treatment Option to Endoscopic Resection for Expanded Indications in Gastric Cancer: a Prospective Cohort Study

Purpose

Expanded indications for endoscopic submucosal dissection (ESD) in early gastric cancer (EGC) remain controversial due to the potential risk of undertreatment after adequate lymph node dissection (LND). Regional LND (RLND) is a novel technique used for limited lymphadenectomy to avoid gastrectomy. This study established the safety and effectiveness of RNLD as an additional treatment option after ESD for expanded indications.

Materials and Methods

A total of 69 patients who met the expanded indications for ESD were prospectively enrolled from 2014 to 2017. The tumors were localized using intraoperative esophagogastroduodenoscopy (EGD) before RLND. All patients underwent RLND first, followed by conventional radical gastrectomy with LND. The locations of the preoperative and intraoperative EGD were compared. Pathologic findings of the primary lesion and the RLND status were analyzed.

Results

The concordance rates of tumor location between the preoperative and intraoperative EGD were 79.7%, 76.8%, and 63.8% according to the longitudinal, circumferential, and regional locations, respectively. Of the 4 patients (5.7%) with metastatic LNs, 3 were pathologically classified as beyond the expanded indication for ESD and 1 had a single LN metastasis in the regional lymph node.

Conclusions

RLND is a safe additional option for the treatment of EGC in patients meeting expanded indications after ESD.

Risk factors for stage underestimation in patients with clinical T1N0 gastric cancer

PURPOSE

Limited gastrectomy has been generally performed in clinical T1N0 gastric cancer. The aim of this study was to identify risk factors for stage underestimation in clinical T1N0 gastric cancer.

METHODS

This study reviewed the medical records of 566 patients who underwent gastrectomy for clinical T1N0 gastric cancer.

RESULTS

The tumor stage was underestimated in 122 (21.6%) patients. The relapse-free survival rate was significantly lower in the patients with pathological stage II (P = 0.021) and III (P < 0.001) disease than in those with pathological stage IA disease. In the multivariate analysis, a location in the upper third of the stomach, tumor size of ≥ 30 mm, undifferentiated adenocarcinoma and clinical tumor depth of SM were identified as independent risk factors for pathological stages II and III. The rate of pathological stages II and III was 0% in the patients with no risk factors, 3% in those with 1 risk factor, 10.5% in those with 2 risk factors, 19.8% in those with 3 risk factors and 50% in those with 4 risk factors.

CONCLUSIONS

Location, tumor size, undifferentiated adenocarcinoma and clinical tumor depth were independent risk factors for pathological stages II and III in clinical T1N0 gastric cancer.

Value of computed tomography evaluation in pathologic classification and prognosis prediction of gastric neuroendocrine tumors

Background

The study aims to investigate the correlation of CT characteristics with pathological classifications and the prognostic value of CT features in patients with gastric neuroendocrine neoplasms (g-NENs).

Methods

Ninety-one cases of pathologically diagnosed g-NENs, including 15 cases of well-differentiated neuroendocrine tumors (NETs) (G1 and G2) and 76 cases of poor-differentiated neuroendocrine carcinomas (NECs) (G3 and MANEC) were retrospectively studied. All cases were included in correlation analysis of CT characteristics with pathologic grades. Among them, 76 patients who had fulfilled follow-up data were included for overall survival (OS) and disease-free survival (DFS) analysis.

Results

CT characteristics that favor poor differentiation include tumor location (fundus and cardia), larger tumor size (>3.0 cm), infiltrative growth, unclear tumor margin, serosa involvement, ulceration and lymph node metastasis (P<0.05). Most variables had sensitivities >80% and specificities >60% to distinguish NECs from NETs. Through log-rank analysis, it was revealed that serosa involvement, cystic degeneration, necrosis, heterogeneous enhancement and lymph node metastasis led to worse DFS and OS for patients with g-NENs (P<0.05). COX regression analysis showed that serosa involvement and lymph node metastasis were independent risk factor for DFS and OS, respectively, despite of grading, staging and therapeutic choices (P<0.05). Moreover, high Ki-67 index (>55%) in G3 g-NENs is in correlation with serosa involvement and lymph node metastasis; accordingly, patients with higher Ki-67 index had worse 1-year DFS (61.7% vs. 92.3%; P<0.05).

Conclusions

CT characteristics can be useful discriminators and prognostic factors for g-NENs and may help identify G3 g-NEC from G3 g-NEN by revealing its poor differentiation and high invasive potential.

DWI-MRI vs CT in gastric MALT lymphoma-preliminary results in 19 patients

OBJECTIVE

To assess the diagnostic performance of [F18] fluoro-2-desoxy-D-glucose positron emission tomography/CT [(18F) FDG-PET/CT] compared to diffusion-weighted imaging (DWI)-MRI of lesion detection in patients with non-FDG avid gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

METHODS

19 patients with histologically proven gastric MALT lymphoma were included in this prospective Institutional Review Board-approved study. Patients underwent [18F]-FDG-PET/CT and consecutive MRI/DWI. Images were evaluated for the presence of gastric lesions in two anatomically defined groups (region 1: cardia, body, fundus; region 2: antrum, pyloric region) by two senior board-certified radiologists, in an observer-blinded manner. Overall accuracy relative to the reference standard (histology obtained by biopsy) was calculated for each reader and a consensus rating.

RESULTS

We found a statistically significant higher accuracy of lesion detection for lesions in region 1 (p = 0.030) and 2 (p = 0.070) for DWI-MRI (100%/78.9%) than for CT (68.4%/42.1%).

CONCLUSION

DWI-MRI seems to be superior accurate to CT for lesion detection in non-FDG avid gastric MALT lymphoma.

ADVANCES IN KNOWLEDGE

DWI-MRI seems to be an alternative reliable imaging method for locoregional disease evaluation of non-FDG avid gastric MALT lymphoma.

Clinical significance of computed tomography-detected ascites in gastric cancer patients with peritoneal metastases

Patients with peritoneal metastases (PM) are generally considered incurable; therefore, the presence of PM is a critical factor in deciding between palliative surgery and curative resection as a therapeutic strategy. Previous studies have not determined the predictive value of ascites detected on computed tomography (CT) for the presence of PM. We aimed to analyze the factors that are associated with PM in patients with CT-detected ascites.A total of 2207 consecutive patients who were diagnosed with gastric cancer between 2004 and 2013 were identified. Eleven patients with liver cirrhosis or chronic renal insufficiency with ascites and 57 patients who received previous treatment were excluded. Ninety-eight patients who had definite evidence of distant metastasis or PM on CT and 64 patients who did not undergo surgery were excluded. A total of 91 patients were enrolled in the study to analyze the association between CT-detected ascites and surgically confirmed PM.Seventy-six patients underwent curative resection and 15 patients underwent palliative surgery. Twelve patients exhibited peritoneal seeding and 37 patients showed regional lymph node metastasis. Regional lymph node metastasis, advanced gastric cancer, undifferentiated pathology, and the amount of ascites were significantly associated with PM. Multivariable logistic regression analysis identified the amount of ascites to be an independent risk factor for the presence of PM.Regional lymph node metastasis, advanced gastric cancer, undifferentiated pathology, and the amount of ascites were associated with PM. The amount of ascites was found to be an independent risk factor for PM.

CT volumetry for gastric adenocarcinoma: association with lymphovascular invasion and T-stages

Purpose

To determine whether gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict presence of lymphovascular invasion and T-stages.

Results

Gross tumor volume increased with the lymphovascular invasion (r = 0.426, P < 0.0001) and T stage (r = 0.656, P < 0.0001). Univariate analysis showed gross tumor volume could predict lymphovascular invasion (P < 0.0001). Multivariate analyses indicated gross tumor volume as an independent risk factor of lymphovascular invasion (P = 0.026, odds ratio = 2.284). The Mann-Whitney U test showed gross tumor volume could distinguish T2 from T3, T1 from T2–T4a, T1–T2 from T3–T4a and T1–T3 from T4a (P = 0.000). In the development cohort, gross tumor volume could predict lymphovascular invasion (cutoff, 15.92 cm³; AUC, 0.760), and distinguish T2 from T3 (cutoff, 10.09 cm³; AUC, 0.828), T1 from T2-T4a (cutoff, 8.20 cm³; AUC, 0.860), T1-T2 from T3-T4a (cutoff, 15.88 cm³; AUC, 0.883), and T1-T3 from T4a (cutoff, 21.53 cm³; AUC, 0.834). In validation cohort, gross tumor volume could predict presence of lymphovascular invasion (AUC, 0.742), and distinguish T2 from T3 (AUC, 0.861), T1 from T2-T4a (AUC, 0.859), T1–T2 from T3–T4a (AUC, 0.875), and T1–T3 from T4a (AUC, 0.773).

Materials and Methods

360 consecutive patients with gastric adenocarcinoma were retrospectively identified. Gross tumor volume was evaluated on multidetector computed tomography images. Statistical analysis was performed to determine whether gross tumor volume could predict presence of lymphovascular invasion and T-stages. Cutoffs of gross tumor volume were first investigated in 212 patients and then validated in an independent 148 patients using area under the receiver operating characteristic curve (AUC) for predicting lymphovascular invasion and T-stages.

Conclusions

Gross tumor volume of resectable gastric adenocarcinoma at multidetector computed tomography demonstrated capability in predicting lymphovascular invasion and distinguishing T-stages.

Computed tomographic characteristics for patients with unresectable gastric cancer harboring low-volume peritoneal carcinomatosis

Although current staging workups could differentiate most patients with operable from inoperable advanced gastric cancers, there are still some patients with low-volume peritoneal carcinomatosis, defined as only metastasis with multiple subcentimeter lesions in peritoneum, receiving unnecessary open-close procedures. The computed tomography (CT) of the patients with unresectable advanced gastric cancer harboring low-volume peritoneal carcinomatosis was retrospectively identified and then thoroughly reviewed by two independent radiologists unaware of the peritoneal carcinomatosis status. Of the 798 patients with newly diagnosed gastric cancer between January 2007 and December 2010, 52 patients harboring advanced gastric cancer with low-volume peritoneal carcinomatosis receiving surgery with curative intent were identified. Descriptive statistic was used for the radiologic characteristics. The most common radiologic characteristic of CT was omental fat stranding (57.7%), followed by omental clustered subcentimeter nodules (53.8%), distant enlarged lymph node (40.4%), distant grouping of small lymph nodes (36.5%), peritoneal nodules or thickening (34.6%), minimal loculated ascites (21.2%), intestinal wall thickening or irregularity (9.6%), and hydronephrosis or hydroureter without stone or urothelial lesion (5.8%). Comprehensively reviewing the radiologic characteristics of CT may identify the patients harboring advanced gastric cancer with low-volume peritoneal carcinomatosis.

Impact of clinical tumor-node-metastasis staging on survival in gastric carcinoma patients receiving surgery

BACKGROUND

Preoperative clinical staging of gastric cancer is used to determine therapeutic strategies. However, the impact of the clinical stage on survival has not been completely investigated, although the relationship between pathologic staging and survival outcome has been reported. The aim of the present study was to clarify the predictability of patient survival based on clinical staging and to evaluate the usefulness of staging as an indicator for selecting the treatment modality.

METHODS

A total of 3033 patients who underwent surgery for gastric cancer were included. A survival analysis was conducted based on the seventh edition of the tumor-node-metastasis (TNM) clinical staging system of the American Joint Committee on Cancer. The predictive ability of the TNM clinical stage for survival was evaluated by Harrell's C-index, a measure of the separation of survival distributions.

RESULTS

The cumulative 5-year survival rates according to the clinical stage were 94.3 % (IA), 84.7 % (IB), 71.7 % (IIA), 56.1 % (IIB), 55.7 % (IIIA), 42.3 % (IIIB), 22.8 % (IIIC), and 9.1 % (IV). Although no significant difference was observed between clinical stages IIB and IIIA (p = 0.865), significant differences existed between all other clinical stages (p < 0.001). Harrell's C-index applied to these results was 0.825 (95 % confidence interval 0.819-0.831).

CONCLUSIONS

The seventh edition of the TNM clinical staging system has a strong prognostic ability with a satisfactory C-index and should be considered valuable for selecting therapeutic strategies for the treatment of gastric cancer.

Negative predictive value of preoperative computed tomography in determining pathologic local invasion, nodal disease, and abdominal metastases in gastric cancer

BACKGROUND

Before undergoing curative-intent resection of gastric adenocarcinoma (ga), most patients undergo abdominal computed tomography (ct) imaging to determine contraindications to resection (local invasion, distant metastases). However, the ability to detect contraindications is variable, and the literature is limited to single-institution studies. We sought to assess, on a population level, the clinical relevance of preoperative ct in evaluating the resectability of ga tumours in patients undergoing surgery.

METHODS

In a provincial cancer registry, 2414 patients with ga diagnosed during 2005-2008 at 116 institutions were identified, and a primary chart review of radiology, operative, and pathology reports was performed for all patients. Preoperative abdominal ct reports were compared with intraoperative findings and final pathology reports (reference standard) to determine the negative predictive value (npv) of ct in assessing local invasion, nodal involvement, and intra-abdominal metastases.

RESULTS

Among patients undergoing gastrectomy, the npv of ct imaging in detecting local invasion was 86.9% (n = 536). For nodal metastasis, the npv of ct was 43.3% (n = 450). Among patients undergoing surgical exploration, the npv of ct for intra-abdominal metastases was 52.3% (n = 407).

CONCLUSIONS

Preoperative abdominal ct imaging reported as negative is most accurate in determining local invasion and least accurate in nodal assessment. The poor npv of ct should be taken into account when selecting patients for staging laparoscopy.

Preoperative Gross Classification of Gastric Adenocarcinoma: Comparison of Double Contrast-Enhanced Ultrasound and Multi-Detector Row CT

The aim of this study was to compare the accuracy of multi-detector computed tomography (MDCT) with double contrast-enhanced ultrasound (DCEUS), in which intravenous microbubbles are used alongside oral contrast-enhanced ultrasound, in determining the gross classification of patients with gastric carcinoma (GC). Altogether, 239 patients with GC proved by histology after endoscopic biopsy were included in this study. DCEUS and MDCT were performed pre-operatively. The diagnostic accuracies of DCEUS and MDCT in determining the gross classification were calculated and compared. The overall accuracy of DCEUS in determining the gross appearance of GC was higher than that of MDCT (84.9% vs. 79.9%, p < 0.001). There was no significant difference in accuracy between DCEUS and MDCT for Borrmann I and IV classifications of advanced gastric cancer (χ(2), p = 0.323 for Borrmann type I, p = 0.141 for Borrmann type IV). The accuracy of DCEUS for early GC and Borrmann II and III classifications of GC was higher than that of MDCT (χ(2), p = 0.000 for all). DCEUS may be regarded as a valuable complementary tool to MDCT in determining the gross appearance of gastric adenocarcinoma pre-operatively.

A novel endoscopic marker for radiological localization and image-guided radiotherapy in esophageal and gastric cancers (with video)

BACKGROUND AND AIMS

Radiotherapy is an accepted modality in the treatment of esophageal cancers and is currently being evaluated in conjunction with chemotherapy for the neoadjuvant treatment of gastric cancers. Our aim was to assess whether a novel endoscopically inserted marker can be used to improve radiological assessment of the primary cancer and allow for image-guided radiotherapy.

METHODS

A phase II feasibility study was conducted at a tertiary-care center. Twenty-six consecutive adult patients with esophagogastric cancers underwent endoscopic marking of the tumor margins with a novel radiopaque marker (mixture of lipiodol and n-butyl 2-cyanoacrylate). The main outcome measure was the successful insertion of the marker based on a combination of radiological, endoscopic, and histological assessment.

RESULTS

A total of 92 markers were inserted in 26 patients. Twenty-two (88%) had follow-up imaging to assess the 81 markers inserted, 79 of which (97.5%) were visible. There were no postprocedural adverse events noted in our cohort. Radiological assessment of tumor size improved such that it was in line with the endoscopic evaluation after marker placement in 18 of 21 patients (85.7%) who had appropriate follow-up radiology imaging. Ten patients (38.5%) from our cohort underwent image-guided radiotherapy (IGRT) by using the endoscopically inserted markers.

CONCLUSION

Within the limitations of our small pilot study, endoscopic placement of our novel marker was successful in the majority of our cohort without significant adverse events. Marker placement resulted in improved radiological localization in the majority of our cohort and allowed for IGRT. (Australian New Zealand Clinical Trials Registry: ACTRN12613000239763.).

MRI of the stomach: a pictorial review with a focus on oncological applications and gastric motility

The purpose of this pictorial review is to demonstrate gastric pathology seen on magnetic resonance imaging (MRI) and discuss the essential MRI sequences for the evaluation of benign and malignant gastric pathologies. Common tumors of the stomach, polyposis syndromes, iatrogenic conditions, as well as other conditions of the stomach will be reviewed. The utility of MRI in the evaluation of patients with gastric malignancies and disorders of gastric motility will also be discussed.

Liver metastasis from hepatoid adenocarcinoma of the stomach mimicking hepatocellular carcinoma: Dynamic computed tomography findings

AIM: To evaluate the dynamic computed tomography (CT) findings of liver metastasis from hepatoid adenocarcinoma of the stomach (HAS) and compared them with hepatocellular carcinoma (HCC).

METHODS: Between January 2000 and January 2015, 8 patients with pathologically proven HAS and liver metastases were enrolled. Basic tumor status was evaluated for the primary tumor location and metastatic sites. The CT findings of the liver metastases were analyzed for tumor number and size, presence of tumor necrosis, hemorrhage, venous tumor thrombosis, and dynamic enhancing pattern.

RESULTS: The body and antrum were the most common site for primary HAS (n = 7), and observed metastatic sites included the liver (n = 8), lymph nodes (n = 7), peritoneum (n = 4), and lung (n = 2). Most of the liver metastases exhibited tumor necrosis regardless of tumor size. By contrast, tumor hemorrhage was observed only in liver lesions larger than 5 cm (n = 4). Three patterns of venous tumor thrombosis were identified: direct venous invasion by the primary HAS (n = 1), direct venous invasion by the liver metastases (n = 7), and isolated portal vein tumor thrombosis (n = 2). Dynamic CT revealed arterial hyperattenuation and late phase washout in all the liver metastases.

CONCLUSION: On dynamic CT, liver metastasis from HAS shared many imaging similarities with HCC. For liver nodules, the presence of isolated portal vein tumor thrombosis and a tendency for tumor necrosis are imaging clues that suggest the diagnosis of HAS.

Laparoscopy, computerised tomography and fluorodeoxyglucose positron emission tomography in the management of gastric and gastro-oesophageal junction cancers

BACKGROUND

The staging laparoscopy has been used in the management of gastrointestinal cancers. The aim of this study was to evaluate the role of staging laparoscopy, in comparison with computed tomography (CT) and fluorodeoxyglucose positron emission tomography (FDG-PET) imaging in staging patients with gastro-oesophageal junction (GOJ) and gastric cancers.

METHODS

The data were collected for patients between 1996 and 2013 undergoing investigation and treatment for GOJ and gastric cancers at a single institute. The pre-operative data (staging data), intraoperative details, post-operative course and follow-up were analysed for individual cases.

RESULTS

Staging laparoscopy altered management plan in 64 (17 %) of 387 patients with negative staging CT and FDG-PET scan. Twenty-seven (7 %) patients with GOJ cancer (types I, II and III) were identified with pathological intraperitoneal nodes, 15 (4 %) gastric cancer with metastatic intraperitoneal deposits and liver metastases and 3 % gastric cancers with positive ascitic fluid for cancer cells. Ten (3 %) of patients were downstaged and were offered curative resection. Patients with metastatic disease were referred for palliative chemotherapy. The overall sensitivity of staging laparoscopy in diagnosing intraabdominal pathology was 86 % in comparison with CT (81 %) and FDG-PET (78 %).

CONCLUSIONS

The diagnostic laparoscopy is useful for detecting and confirming nodal involvement and distant metastatic disease not evident on the staging CT scan and FDG-PET. This could potentially alter treatment and prognosis in patients with upper gastrointestinal cancer. The diagnostic laparoscopy should be performed as part of investigation and treatment planning for patients suffering from GOJ and gastric cancers. This can help to avoid surgery in patients with advanced disease.

Accuracy of EUS and CT imaging in preoperative gastric cancer staging

BACKGROUND

Neoadjuvant therapy is recommended for locally advanced gastric cancer patients (stage IB-IIIC). The objective of this study is to evaluate the accuracy of endoscopic ultrasound (EUS) and computed tomography (CT) in identifying patients with locally advanced gastric cancer.

METHODS

Patients with gastric adenocarcinoma who underwent gastrectomy at our institution were reviewed. Preoperative EUS and CT staging were compared with pathologic staging to determine accuracy.

RESULTS

Between 2001 and 2013, 280 patients were identified. Forty-nine patients (18%) who underwent preoperative staging by EUS were analyzed. The accuracy of EUS in identifying individual T stage and N stage was 41.0% and 42.9%, respectively. EUS had moderate accuracy in differentiating locally advanced from early (stage 0-IA) disease (75.5%, area under curve (AUC) 0.772). For individual T stage and N stage, the accuracy of CT was 4.0% and 56%, respectively. CT had relatively poor accuracy in differentiating locally advanced from early disease (60.0%, AUC 0.649).

CONCLUSIONS

EUS and CT had poor performance in identifying individual T and N stage although EUS demonstrated moderate accuracy in identifying patients with locally advanced disease. A combined staging approach, in addition to further optimization of staging modalities, is required for accurate staging for patients with gastric cancer.

Preoperative CA 125 is significant indicator of curative resection in gastric cancer patients

AIM: To investigate the correlation among tumor markers, curative resection, and recurrence in gastric cancer.

METHODS: The patients with preoperative tumor makers [Carcinoembryonic antigen, Carbohydrate antigen (CA) 19-9, and CA 125] and elective gastrectomy between January 2000 and December 2009 at Chungbuk National University Hospital were enrolled in this study. We analyzed the relationship among the tumor makers, curative resection and recurrence, retrospectively.

RESULTS: Among the 679 patients with gastric cancer, curative resection was 93.6% (n = 636) and non-curative resection was 6.4% (n = 43). The independent risk factors for the non-curative resection were tumor location and the positivity of preoperative serum CA 19-9 and CA 125 levels. After curative resection, the independent prognostic risk factors for recurrence in curative resection were gender, stage, and preoperative increased serum CA 125 level (HR = 2.431, P =0.020), in a multivariate analysis.

CONCLUSION: Preoperative CA 125 is a useful predictive biomarker for curative resection and prognostic biomarker for recurrence in gastric cancer patients.

A pilot study of EUS-guided fiducial insertion for the multidisciplinary management of gastric cancer

BACKGROUND AND STUDY AIMS

The 5-year survival rates for gastric cancer remain poor despite evolving therapies, and fiducial insertion via endoscopic ultrasound (EUS) is novel within this setting. We aimed to assess the feasibility of fiducial insertion for response assessment and anatomic localization in patients with gastric cancer.

PATIENTS AND METHODS

A prospective phase II feasibility study was undertaken at Austin Health (Victoria, Australia) from February 2011 to November 2012. Consecutive adult patients were enrolled who had primary adenocarcinoma of the stomach with American Joint Committee on Cancer stage T1 - 3,N0 - 1,M0 - 1a and Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1. In addition, the patients were medically suitable for gastrectomy and chemotherapy/chemoradiotherapy. Gold fiducial markers were inserted under EUS guidance into the margins of the gastric cancer primary. The main outcome was successful insertion of the fiducial without complications for response assessment and anatomic localization.

RESULTS

A total of 15 fiducials were successfully inserted into 7 (88 %) of 8 patients. No immediate or delayed complications were noted. One patient proceeded to image-guided radiotherapy through the use of fiducials and is disease free at 12 months. Fiducials were used to assess treatment response in all patients who underwent computed tomographic imaging after insertion. Follow-up computed tomography with fiducial placement improved anatomic localization and estimation of the gastric cancer primary size in 3 (60 %) of 5 patients.

CONCLUSIONS

Within the limitations of our small study cohort, fiducials were placed in gastric cancers under EUS guidance without complications, and placement was successful in the majority of our patients. Although potential benefits exist, there remain substantial limitations to the generalization of this technique across our patient population.

Accuracy of multidetector-row CT in diagnosing lymph node metastasis in patients with gastric cancer

OBJECTIVES

The purpose of this study was to determine the optimal cut-off value of lymph node size for diagnosing metastasis in gastric cancer with multidetector-row computed tomography (MDCT) after categorizing perigastric lymph nodes into three regions.

METHODS

The study included 90 gastric cancer patients who underwent gastrectomy. The long-axis diameter (LAD) and short-axis diameter (SAD) of all visualized lymph nodes were measured with transverse MDCT images. The locations of lymph nodes were categorized into three regions: lesser curvature, greater curvature, and suprapancreatic. The diagnostic value of lymph node metastasis was assessed with receiver operating characteristic (ROC) analysis.

RESULTS

The area under the curve was larger for SAD than LAD in all groups. The optimal cut-off values of SAD were determined as follows: overall, 9 mm; differentiated type, 9 mm; undifferentiated type, 8 mm; lesser curvature region, 7 mm; greater curvature region, 6 mm; and suprapancreatic region, 9 mm. The diagnostic accuracies for lymph node metastasis using individual cut-off values were 71.1% based on histological type and 76.6% based on region of lymph node location.

CONCLUSIONS

The diagnostic accuracy of lymph node metastasis in gastric cancer was improved by using individual cut-off values for each lymph node region.

KEY POINTS

• Multidetector-row computed tomography is widely used to predict pathological nodal status. • An optimal cut-off value of lymph node size has not been determined. • Cut-off values were assessed according to histology and nodal location. • The optimal cut-off values differed based on histology and nodal location. • Diagnostic accuracy was improved by using individual cut-off values for each region.

Temporal evolution of multidetector CT findings after endoscopic submucosal dissection in patients with early gastric cancer: correlation with endoscopy

OBJECTIVE

To assess changes over time in imaging findings retrospectively by multidetector CT (MDCT) with two-dimensional (2D) multiplanar reconstruction and three-dimensional (3D) CT gastrography (CTG), after endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC), and to correlate 3D CT images with endoscopic appearance.

MATERIALS AND METHODS

In this retrospective study, a total of 84 patients underwent ESD and were followed up with MDCT. Fifteen patients underwent CT twice, and 3 patients underwent CT 3 times. A total of 105 CTs were included in this study and 43 CTs contained 3D CTGs. Two radiologists in consensus interpreted CT images for lesion detectability, presence and characteristics of ulcer, focal wall thickening, perigastric fat infiltration, and overlying enhancing layer in 2D images. The presence of ulcer or subtle mucosal nodularity, ulcer mound, and fold convergence were analysed in 3D CT images. We also assessed the time interval between ESD and CT and analysed the temporal evolution of CT findings. The sensitivity, specificity, and overall accuracy of 3D CTG were assessed regarding endoscopic features as the gold standard.

RESULTS

The mean interval between ESD and follow up CT was 76.9 days (median, 62; range, 2-223). No tumour recurrence in any lesion was found on follow-up endoscopic biopsy and also lymph node or distant metastasis was not observed on CT exams in the follow-up period. The lesion detectability in a total of 105 post-ESD 2D CT images was 42.0% (44/105), and 93.2% (41/44) of the detected lesions were visualizable 2 months after ESD. Focal wall thickening was observed during the entire follow-up period in all patients. Perigastric fat infiltration was observed in 4 lesions within 1 week of ESD. Overlying enhancing layer appeared in 27 lesions without temporal evolution. On a total of 43 post-ESD 3D CTG, lesion detectability was 76.7% (33/43), and lesions could be visualized for a longer period than by 2D CT images (223 days versus 99 days). Three-dimensional imaging features revealed ulcer, ulcer mound, and fold convergence. Ulcer mounds disappeared first (median, 12.5 days; range, 2-14 days after ESD), ulcers appeared up to 4 months after ESD (median, 14 days; range, 2-174 days after ESD) and fold convergence continued to the end of the study (median, 74 days; range, 2-223 days after ESD). We found that sensitivity, specificity, and overall accuracy of 3D CTG were 70.0%, 92.9%, 83.3% for ulcer, 28.6%, 100%, 71.4% for ulcer mound, and 71.4%, 100%, 75% for fold convergence regarding endoscopy, respectively.

CONCLUSION

On follow-up 2D or 3D CT images after ESD, early findings were of perigastric fat infiltration, ulcer, and surrounding oedema. Focal wall thickening and fold convergence continued to be observed late in the study. The overlying enhancing layer did not show temporal evolution.

Extent of arterial tumor enhancement measured with preoperative MDCT gastrography is a prognostic factor in advanced gastric cancer after curative resection

OBJECTIVE

The objective of this study was to investigate the correlation between pathologic findings and arterial tumor enhancement at MDCT gastrography of patients with a prognosis of advanced gastric cancer after curative resection.

MATERIALS AND METHODS

The cases of 41 patients with advanced gastric cancer (23 men, 18 women; age range, 35-92 years; median, 60 years) who underwent MDCT gastrography and optical endoscopy before surgery were retrospectively evaluated. Two radiologists reviewed virtual endoscopic and multiplanar reconstruction images to measure arterial phase CT values of the inner tumor margin and healthy gastric wall. They used consensus regions of interest on a cross-sectional image of the largest tumor diameter and then calculated tumor-to-normal wall enhancement ratio (TNR). Advanced gastric cancers were divided into high- and low-TNR groups with mean TNR as the cutoff. The correlations between groups and pathologic factors, patient survival, and mode of recurrence were studied.

RESULTS

Multivariate logistic regression analysis showed that the arterial tumor enhancement ratio correlated with both microvessel density and lymphatic vessel invasion. The survival rate after curative resection was worse for the high-TNR group than for the low-TNR group. The rate of lymphatic and hematogenous recurrences was also higher in the high-TNR group. Multivariate survival analysis revealed that TNR was an independent prognostic factor.

CONCLUSION

The extent of arterial tumor enhancement correlated with tumor angiogenesis and lymphatic vessel invasion and was a useful prognostic indicator after curative resection in patients with advanced gastric cancer.

Assessment of (18)F-fluorodeoxyglucose positron emission tomography combined with computed tomography in the preoperative management of patients with gastric cancer

BACKGROUND

The significance of (18)F-2-deoxy-2-fluoro-glucose positron emission tomography combined with computed tomography imaging (FDG-PET/CT) in the diagnosis of gastric cancer remains controversial. This study aimed to evaluate the efficacy of preoperative FDG-PET/CT in staging of gastric cancer.

METHODS

FDG-PET/CT results for 90 patients with gastric cancer were retrospectively examined. For quantitative PET analysis, FDG uptake was assessed based on the maximum standardized uptake values (SUVmax).

RESULTS

FDG-PET/CT detected the primary gastric cancer in 71 of the 90 patients (sensitivity 78.9 %). The median SUVmax was significantly higher in patients with T3/T4 disease than in those with T1/T2 (9.0 vs. 3.8; P < 0.001), in patients with distant metastasis than in those with no metastasis (9.5 vs. 7.7; P = 0.018), and with stage III/IV tumors than in those with stage I/II (9.0 vs. 4.7; P = 0.017). The SUVmax of the primary tumor was significantly correlated with tumor size (r = 0.461, P < 0.001). The sensitivity, specificity, and accuracy of FDG-PET/CT in assessing metastasis to regional lymph nodes were 64.5, 85.7, and 71.1 %, respectively.

CONCLUSIONS

FDG-PET/CT results are significantly associated with tumor progression in gastric cancer, and such findings can reliably identify cancer cell populations.

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.

Differential diagnosis between benign and malignant ulcers: 320-row CT virtual gastroscopy

PURPOSE

This study aims to assess the diagnostic accuracy of virtual gastroscopy obtained by 320-row computed tomography (CT) examination in differentiating benign from malignant gastric ulcers (GUs).

MATERIALS AND METHODS

49 patients (30 M, 19 F, mean age 58.6) with endoscopic and histological diagnosis of GU underwent CT examination. A hypotonizing drug was administered and gastric walls were distended by air in order to perform virtual endoscopy. Based on morphological features, GUs were subdivided into benign or malignant forms by two blinded radiologists. Interobserver agreement was evaluated using Cohen’s kappa (κ) test. CT results were then compared with endoscopic and histological findings, having the latter as the reference standard.

RESULTS

Thirty-five out of 49 patients (71%) were affected by malignant ulcers, while in the remaining 14 cases diagnosis of benign GU was made. Virtual gastroscopy showed diagnostic accuracy, sensitivity, and specificity values of 94%, 91%, and 100%, respectively, in differentiating benign from malignant ulcers. Almost perfect agreement between the two readers was found (κ = 0.86).

CONCLUSION

CT virtual gastroscopy improves the identification of GUs and allows differentiating benign from malignant forms.

Gastric cancer staging with dual energy spectral CT imaging

Purpose

To evaluate the clinical utility of dual energy spectral CT (DEsCT) in staging and characterizing gastric cancers.

Materials and Methods

96 patients suspected of gastric cancers underwent dual-phasic scans (arterial phase (AP) and portal venous phase (PP)) with DEsCT mode. Three types of images were reconstructed for analysis: conventional polychromatic images, material-decomposition images, and monochromatic image sets with photon energies from 40 to 140 keV. The polychromatic and monochromatic images were compared in TNM staging. The iodine concentrations in the lesions and lymph nodes were measured on the iodine-based material-decomposition images. These values were further normalized against that in aorta and the normalized iodine concentration (nIC) values were statistically compared. Results were correlated with pathological findings.

Results

The overall accuracies for T, N and M staging were (81.2%, 80.0%, and 98.9%) and (73.9%, 75.0%, and 98.9%) determined with the monochromatic images and the conventional kVp images, respectively. The improvement of the accuracy in N-staging using the keV images was statistically significant (p<0.05). The nIC values between the differentiated and undifferentiated carcinoma and between metastatic and non-metastatic lymph nodes were significantly different both in AP (p = 0.02, respectively) and PP (p = 0.01, respectively). Among metastatic lymph nodes, nIC of the signet-ring cell carcinoma were significantly different from the adenocarcinoma (p = 0.02) and mucinous adenocarcinoma (p = 0.01) in PP.

Conclusion

The monochromatic images obtained with DEsCT may be used to improve the N-staging accuracy. Quantitative iodine concentration measurements may be helpful for differentiating between differentiated and undifferentiated gastric carcinoma, and between metastatic and non-metastatic lymph nodes.

Effectiveness of endoscopic clipping and computed tomography gastroscopy for the preoperative localization of gastric cancer

Purpose

Before laparoscopic gastrectomy for gastric cancer can be planned, it is very important to know the precise location of the tumor. The aim of this study was to evaluate 3 methods of predicting the exact location of the tumor: preoperative gastrofibroscopy (GFS), preoperative computed tomography gastroscopy (CT), and intraoperative gastroscopy-guided laparoscopy (Lap).

Methods

In this study, 15 patients were prospectively identified, and endoscopic clips were preoperatively placed on the proximal 1 cm of the tumor, at the angle on the greater curvature and opposite the angle on the greater curvature. The distances between the pylorus and the proximal tumor clip (PT), the angle clip (PA), the greater curvature clip (PG), and the gastroesophageal junction were measured by preoperative GFS, preoperative CT, intraoperative Lap, and visual inspection (Vis).

Results

PT, PA, and PG values measured by preoperative GFS differed significantly from the Vis values (P < 0.01). However, preoperative CT measurements of PT, PA, and PG did not differ from the Vis values (P = 0.78, P = 0.48, and P = 0.53, respectively). Intraoperative Lap and Vis PT values differed by only 1.1 cm on an average (P = 0.10), but PA and PG values varied by 1.9 and 3.4 cm, respectively (P = 0.01 for both).

Conclusion

Endoscopic clipping combined with preoperative CT gastroscopy is more useful than preoperative GFS for preoperatively predicting the location of early gastric cancers and will be helpful for planning laparoscopic gastrectomy.

The role of CT and staging laparoscopy in the staging of gastric cancer

AIM

To assess the relative roles of computed tomography (CT) and diagnostic laparoscopy in the staging process of patients with potentially curable gastric cancer.

MATERIALS AND METHODS

Fifty-two patients underwent laparoscopy and CT as part of staging; 36 patients underwent surgery without laparoscopy. Pathological findings at laparoscopy or surgery were compared with initial CT reports, and analysis of the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) was performed.

RESULTS

Of the patients who underwent laparoscopy and CT, six were staged as positive for peritoneal disease (PD), of which five (83%) were positive for PD at laparoscopy. Forty-six patients were reported at CT as negative for PD, of which 40 (87%) were negative at laparoscopy. Of 36 patients with no advanced disease at CT, who had surgery without diagnostic laparoscopy, nine (25%) were positive at surgery for PD. The overall sensitivity of CT for PD was therefore 25%, the specificity was 99%, the PPV was 86%, and the NPV was 83%.

CONCLUSION

CT is not sufficiently sensitive to detect or exclude PD in patients with gastric cancer, although is highly specific. Staging laparoscopy is an essential adjunct to imaging in all patients being considered for curative surgery for gastric cancer.

How useful is preoperative imaging for tumor, node, metastasis (TNM) staging of gastric cancer? A meta-analysis

BACKGROUND

Surgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.

METHODS

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.

RESULTS

For pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥ 4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.

CONCLUSIONS

The agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.

A systematic review of the accuracy and indications for diagnostic laparoscopy prior to curative-intent resection of gastric cancer

BACKGROUND

Despite improved preoperative imaging techniques, patients with incurable or unresectable gastric cancer are still subjected to non-therapeutic laparotomy. Diagnostic laparoscopy (DL) has been advocated by some to be essential in decision-making in gastric cancer. We aimed to identify and synthesize findings on the value of DL for patients with gastric cancer, in this era of improved preoperative imaging.

METHODS

Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We calculated the change in management and avoidance of laparotomy based on the addition of DL and laparoscopic ultrasound (LUS). The accuracy, agreement (kappa), sensitivity, and specificity of DL in assessing tumor extent, nodal involvement, and the presence of metastases with respect to the gold standard (pathology) were also calculated.

RESULTS

Twenty-one articles were included. DL showed moderate to substantial agreement with final pathology for T stage, but only fair agreement for N stage. For M staging, DL had an overall accuracy, sensitivity, and specificity ranging from 85-98.9%, 64.3-94%, and 80-100%, respectively. The use of DL altered treatment in 8.5-59.6% of cases, avoiding laparotomy in 8.5-43.8% of cases. LUS provided additional benefit in 5.8-7.2% of cases.

CONCLUSIONS

Despite evolving preoperative imaging techniques, diagnostic laparoscopy continues to be of substantial value in staging patients with gastric cancer and in avoiding unnecessary laparotomy. The current data support DL for all patients with advanced gastric cancer.

FDG PET imaging in the staging and management of gastric cancer

Gastric cancer is a leading cause of cancer death worldwide. Complete resection offers the only chance for permanent control, and accurate staging and evaluation of treatment response are crucial for appropriate management. Positron Emission Tomography (PET) is increasingly used to complement anatomic imaging in cancer management. PET use in gastric cancer has been limited by 1) some gastric histologies are not PET avid, 2) spatial resolution limits the ability to distinguish between primary tumor and compartment I or II lymph nodes, and 3) the lack of a unified criteria in how to interpret PET for management decisions. New criteria have been proposed establishing response metrics in the utilization of PET. More study is needed to support these criteria in routine practice and establish the place of PET in the staging and management of gastric cancer.

Preoperative plasma fibrinogen level is a useful predictor of adjacent organ involvement in patients with advanced gastric cancer

Purpose

The aim of the present study was to assess the association between the pre-operative plasma fibrinogen level and the adjacent organ involvement in advanced gastric cancer.

Materials and Methods

A total of 923 pre-operative plasma samples were obtained from 923 patients diagnosed clinically as having advanced gastric cancer, and fibrinogen levels were measured by immunoassay. Associations between fibrinogen levels and clinicopathologic findings (depth of tumor, adjacent organ involvement, and lymph node metastasis), along with survival were examined by univariate and multivariate analyses.

Results

Tumor size, tumor depth, and the presence of lymph node metastasis were found to be positively correlated with the preoperative plasma fibrinogen levels (P<0.001). Fifty (5.4%) patients had adjacent organ involvement. Lymphatic invasion (P<0.001), tumor size (P<0.001), clinical T (depth of invasion) stage (P<0.001), and clinical nodal stage (P=0.018) were found to be associated with adjacent organ involvement. Univariate and multivariate regression analyses showed that a preoperatively elevated plasma fibrinogen level was associated with adjacent organ involvement (P<0.001, 0.028), and Kaplan-Meier analysis showed that it was associated with poorer survival (P<0.001).

Conclusions

Plasma fibrinogen was found to be a clinically useful marker of adjacent organ involvement and overall survival. When a high fibrinogen level is encountered, preoperatively, adjacent organ involvement should be suspected in clinically advanced gastric cancer.

Benign regional lymph nodes in gastric cancer on multidetector row CT

BACKGROUND

Benign regional lymph nodes (LNs) are sometimes enlarged in gastric cancer patients due to reactive or inflammatory changes. Frequently these enlarged LNs can mimic LN metastasis and lead to overstaging.

PURPOSE

To assess frequency of benign regional LNs in gastric cancer patients compared with that in a healthy population and to assess the frequency of benign regional LNs in gastric cancer according to T-staging.

MATERIAL AND METHODS

Between August 2005 and June 2009, 177 patients with surgically proven gastric cancer without LN metastasis (TanyN0M0) who had previously undergone preoperative multidetector row CT (MDCT) and 168 healthy patients who visited the healthcare center and underwent an abdominal MDCT were included in this retrospective study. An abdominal radiologist evaluated the distribution of regional LNs and measured the short diameter of LNs ≥6 mm, ≥8 mm, and ≥10 mm. The number of enlarged benign LNs was compared between the two groups, and the distribution of LN with regard to T-stage of gastric cancer was also evaluated.

RESULTS

At least one LN ≥6 mm, ≥8 mm, and ≥10 mm was detected in 64.4% (114/177), 22.0% (39/177), and 4.0% (7/177) of patients in the gastric cancer group, respectively, compared to 29.8% (50/168), 4.2% (7/168), and 0% of patients in the healthy group, respectively. The difference between the two groups was statistically significant (P <0.0001). The LN ≥8 mm was found in 14.9% (20/134) in early gastric cancer (T1), and 44.2% (19/43) in advanced cancer (T2 or higher); the difference was statistically significant (P = 0.0002). However, the frequency of LN ≥6 mm in mucosal cancer (T1a) and submucosal cancer (T2b) was not significantly different, regardless of its size.

CONCLUSION

Benign regional LNs ≥6 mm are more frequently detected in gastric cancer patients than in a healthy population and in advanced gastric cancer than in early cancer.

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.

Phase II trial of combined treatment consisting of preoperative S-1 plus cisplatin followed by gastrectomy and postoperative S-1 for stage IV gastric cancer

BACKGROUND

To improve the poor prognosis in patients with stage IV (StIV) gastric cancer (GC), we conducted a multicenter phase II study of preoperative S-1 plus cisplatin followed by gastrectomy and postoperative S-1 for StIV GC (the protocol is registered at the clinical trial site of the National Cancer Institute; KYUH-UHA-GC03-01, NCT00088816).

METHODS

Eligibility criteria included histologically proven StIVGC. Patients received S-1 (80 mg/m(2)/day, days 1-21) plus cisplatin (60 mg/m(2) on day 8) for 2 courses. After preoperative chemotherapy (CTx), radical gastrectomy was performed. Postoperative S-1 (80 mg/m(2)/day, days 1-14) was administered every 3 weeks for 1 year.

RESULTS

Fifty-one patients were enrolled and all patients were followed for more than 2 years. The 2-year overall survival and progression-free survival rates were 43.1% (95% confidence interval [CI] 29.4-56.1%) and 33.3% (95% CI 20.9-46.2%), respectively. Preoperative chemotherapy was accomplished in 44 patients (86.3%). These 44 patients underwent surgery and R0 resection was achieved in 26. The rate of R0 resection for GC with a single StIV factor (n = 24) was 79.2% and that for GC with multiple StIV factors (n = 27) was 25.9%. All patients with cancer cells in peritoneal washings (cytology [Cy] 1) alone (n = 12) became Cy0 after preoperative chemotherapy. Postoperative chemotherapy was completed in 11 patients, including 8 with Cy1 alone. No treatment-related death was recorded. Recurrences were observed in 14 patients after R0 resection. The most frequent recurrence site was the peritoneum. Patients who underwent R0 resection and those with Cy1 alone had a better survival.

CONCLUSIONS

This perioperative treatment was safe and feasible for StIVGC but failed to show a survival benefit. In patients with StIVGC with Cy1 alone this treatment resulted in a better prognosis.

Diagnostic performance of 64-section CT using CT gastrography in preoperative T staging of gastric cancer according to 7th edition of AJCC cancer staging manual

OBJECTIVES

To evaluate the accuracy of 64-section multidetector CT with CT gastrography for determining the depth of mural invasion in patients with gastric cancer according to the 7th edition of the AJCC cancer staging manual.

METHODS

A total of 127 patients with gastric cancer and who had undergone both esophago-gastro-duodenoscopy and 64-section CT were included in this study. Two radiologists independently reviewed the preoperative CT images with respect to the detectability and T-staging of the gastric cancers. The sensitivity, specificity, accuracy and overall accuracy of each reviewer for the T staging of gastric cancer were calculated.

RESULTS

Overall, gastric cancer was detected in 123 (96.9%) of the 127 cancers on the CT images. Reviewer 1 correctly staged 98 gastric cancers, and reviewer 2 correctly classified 105 gastric cancers. The overall diagnostic accuracy of the T staging was 77.2% (98/127) for reviewer 1 and 82.7% (105/127) for reviewer 2.

CONCLUSION

64-section CT using CT gastrography showed a reasonable diagnostic performance for determining the T staging in patients with gastric cancer according to the 7th edition of the AJCC cancer staging manual.

KEY POINTS

64-section CT is useful for determining the T staging of gastric cancer Virtual gastroscopy is helpful for detecting early gastric cancer New CT criteria may be applicable to the T staging The normal gastric wall frequently shows a multilayered pattern.

A risk score system to preoperatively predict TNM stages in gastric cancer

BACKGROUND

To improve the estimation of tumor status and facilitate the stage-dependent treatment planning, we developed a reliable and easy-to-use risk score for prediction of tumor-node-metastasis stages in gastric cancer.

METHODS

Clinicopathological data were collected prospectively from 108 curatively resected patients with gastric cancer. The risk score was established on the basis of independent predictive factors for tumor stages, and its performance was evaluated by receiver operating characteristic (ROC) analysis.

RESULTS

The following 4 independent factors were included in our score: serum albumin levels, tumor size, T and N categories determined by helical computed tomography. Using ROC analysis, we chose a score at 7 as the optimal cut point for differentiating the more advanced disease (stage III/IV) from the less advanced one (stage I/II). With the defined cut point, our score allowed predicting stage III/IV with sensitivity of 79.6%, specificity of 85.2%, and accuracy of 82.4%. The discriminative ability of this score was good (the area under the ROC curve, 0.861-0.965).

CONCLUSIONS

The risk score may be helpful to preoperative gastric cancer staging. It probably assists surgeons in deciding the extent of surgery and in choosing the appropriate perioperative adjuvant therapies.

Impact of pretherapeutic routine clinical staging for the individualization of treatment in gastric cancer patients

PURPOSE

The usefulness and prognostic impact of a pretherapeutic clinical staging is still a matter of discussion. However, a pretherapeutic estimation of the prognosis would be essential to adjust the patient's therapy. Our aim was to compare clinical and histopathological staging and to analyze the predictive value of routine clinical staging and its significance for the individualization of treatment.

PATIENTS AND METHODS

We analyzed the data of 368 patients treated with gastric cancer in the University of Heidelberg, Department of Surgery, from January 2001 to June 2009. Pretherapeutic parameters including sex, age, cTNM, grading, Laurén classification, tumor localization, as well as posttherapeutic parameters were analyzed, and their impact for survival was evaluated. Follow-up data was obtained for all patients (2.17% lost to follow-up).

RESULTS

The overall accuracy was 64.1% for pT category, 54.5% for pN category, and 80.3% for M category for the primary resected patients. For the patients treated neoadjuvantly, the overall accuracy was 21.8% for the pT category, 58.0% for the pN category, and 80.0% for the M category. The prognosis was associated to the age (p = 0.017), tumor localization (p < 0.001), grading (p = 0.041), cT category (p < 0.001), cN category (p < 0.001), and cM category (p = 0.001). The multivariate analysis, including pre- and postoperative factors, revealed tumor localization (p = 0.002), cN category (p = 0.019), and metastatic lymph node rate (p < 0.001) as independent prognostic factors.

CONCLUSION

The accordance between clinical and histopathological staging is limited, but nevertheless pretherapeutic parameters have a high prognostic impact and could be used for individualized therapy planning. The relevant pretherapeutic prognostic factors can all be determined by routine clinical staging including CT and endoscopy. Consequently pretherapeutic prognostic evaluation and therapy planning seem to be feasible with routine staging methods.

Lymph node metastasis of gastric cancer

Despite a decrease in incidence in recent decades, gastric cancer is still one of the most common causes of cancer death worldwide [1]. In areas without screening for gastric cancer, it is diagnosed late and has a high frequency of nodal involvement [1]. Even in early gastric cancer (EGC), the incidence of lymph node (LN) metastasis exceeds 10%; it was reported to be 14.1% overall and was 4.8 to 23.6% depending on cancer depth [2]. It is important to evaluate LN status preoperatively for proper treatment strategy; however, sufficient results are not being obtained using various modalities. Surgery is the only effective intervention for cure or long-term survival. It is possible to cure local disease without distant metastasis by gastrectomy and LN dissection. However, there is no survival benefit from surgery for systemic disease with distant metastasis such as para-aortic lymph node metastasis [3]. Therefore, whether the disease is local or systemic is an important prognostic indicator for gastric cancer, and the debate continues over the importance of extended lymphadenectomy for gastric cancer. The concept of micro-metastasis has been described as a prognostic factor [4-9], and the biological mechanisms of LN metastasis are currently under study [10-12]. In this article, we review the status of LN metastasis including its molecular mechanisms and evaluate LN dissection for the treatment of gastric cancer.

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.

Has the accuracy of preoperative diagnosis improved in cases of early-stage gastric cancer?

BACKGROUND

Adequate preoperative evaluation for gastric cancer staging is essential to develop an individualized treatment strategy involving surgery with reduced lymphadenectomy and laparoscopic gastrectomy.

METHODS

A total of 509 gastric cancer patients with clinical Stage IA or IB disease were divided into two groups: 304 patients were admitted in 2000 or earlier (Group A), and 205 patients were admitted in 2001, when multidetector computed tomography (MD-CT) was available, or later (Group B). We evaluated the accuracy of the preoperative diagnoses of tumor depth, lymph node involvement, and tumor stage.

RESULTS

With respect to tumor depth, 94.5 and 52.8% of patients were staged correctly in cT1 and cT2 patients, respectively. Among both cT1 and cT2 patients, the underestimated rates were lower in Group B than in Group A. For nodal metastasis, 83.2 and 30.0% of patients were staged correctly in cN0 and cN1 patients, respectively. Among the cN0 patients, 82.1 and 84.7% of Group A and Group B patients, respectively, were staged correctly. Among the cN1 patients, none of the patients in Group B was underestimated, while 9.7% of Group A patients were underestimated. There was a significant increase in the percentage of correctly staged patients and a decrease in the percentage of underestimated patients in Group B in comparison to Group A in both cStage IA and cStage IB patients.

CONCLUSIONS

Remarkable advances have been observed in the accuracy of preoperative staging in the early stage of gastric cancer. However, it is necessary to continue to develop accurate preoperative and intraoperative diagnostic systems.

[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.

R0 resection in the treatment of gastric cancer: Room for improvement

Gastric carcinoma is one of the most frequent malignancies in the world and its clinical behavior especially depends on the metastatic potential of the tumor. In particular, lymphatic metastasis is one of the main predictors of tumor recurrence and survival, and current pathological staging systems reflect the concept that lymphatic spread is the most relevant prognostic factor in patients undergoing curative resection. This is compounded by the observation that two-thirds of gastric cancer in the Western world presents at an advanced stage, with lymph node metastasis at diagnosis. All current therapeutic efforts in gastric cancer are directed toward individualization of therapeutic protocols, tailoring the extent of resection and the administration of preoperative and postoperative treatment. The goals of all these strategies are to improve prognosis towards the achievement of a curative resection (R0 resection) with minimal morbidity and mortality, and better postoperative quality of life.

Essential pre-treatment imaging examinations in patients with endoscopically-diagnosed early gastric cancer

Background

There have been no reports discussing which imaging procedures are truly necessary before treatment of endoscopically-diagnosed early gastric cancer (eEGC). The aim of this pilot study was to show which imaging examinations are essential to select indicated treatment or appropriate strategy in patients with eEGC.

Methods

In 140 consecutive patients (95 men, 45 women; age, 66.4 +/- 11.3 years [mean +/- standard deviation], range, 33-90) with eEGC which were diagnosed during two years, the pre-treatment results of ultrasonography (US) and contrast-enhanced computed tomography (CT) of the abdomen, barium enema (BE) and chest radiography (CR) were retrospectively reviewed. Useful findings that might affect indication or strategy were evaluated.

Results

US demonstrated useful findings in 13 of 140 patients (9.3%): biliary tract stones (n = 11) and other malignant tumors (n = 2). Only one useful finding was demonstrated on CT (pancreatic intraductal papillary mucinous tumor) but not on US (0.7%; 95% confidential interval [CI], 2.1%). BE demonstrated colorectal carcinomas in six patients and polyps in 10 patients, altering treatment strategy (11.4%; 95%CI, 6.1-16.7%). Of these, only two colorectal carcinomas were detected on CT. CR showed three relevant findings (2.1%): pulmonary carcinoma (n = 1) and cardiomegaly (n = 2). Seventy-nine patients (56%) were treated surgically and 56 patients were treated by endoscopic intervention. The remaining five patients received no treatment due to various reasons.

Conclusions

US, BE and CR may be essential as pre-treatment imaging examinations because they occasionally detect findings which affect treatment indication and strategy, although abdominal contrast-enhanced CT rarely provide additional information.