Multidetector computed tomography in the preoperative staging of gastric adenocarcinoma

Radiomics analysis of dual-energy CT-derived iodine maps for differentiating between T1/2 and T3/4a in gastric cancer: A multicenter study

OBJECTIVE

To investigate the value of radiomic analysis of dual-energy CT (DECT)-derived iodine maps (IMs) for the differentiation between T1/2 and T3/4a stage tumors in gastric cancer (GC).

METHODS

A total of 263 patients who received upfront surgery and were pathologically confirmed with gastric adenocarcinoma were enrolled in this study. Dual-phase enhanced CT scans with gemstone spectral imaging (GSI) mode were performed within two weeks before surgery. 151 patients were retrospectively collected for the training (n = 105) and validation (n = 46) cohorts, and 112 patients were prospectively collected for the external test1 (n = 68) and external test2 (n = 44) cohorts. According to the postoperative pathological T stage, patients were classified into T1/2 and T3/4a stage groups. Clinical characteristics were recorded and quantitative iodine concentration (IC) of tumors was measured. Radiomics features were extracted from the venous phase (VP) IMs by three-dimensional region of interest (3D-ROI) segmentation. Feature selection was performed using the least absolute shrinkage and selection operator. Four machine learning algorithms, including random forest, logistic regression, naive Bayes, and support vector machine, were used to construct radiomics models. Finally, the most valuable clinical characteristics, DECT parameters, and the best radiomics model were combined to build a nomogram. The diagnostic performance of nomogram was evaluated by the area under receiver operating characteristic curve (AUC), calibration curve, and decision curve.

RESULTS

The nomogram combined tumor clinical T stage (cT), tumor thickness, venous-phase iodine concentration (ICVP), normalized arterial-phase iodine concentration (nICAP), and Radscore (derived from logistic regression model). This integrated model demonstrated favorable performance in the differentiation between T1/2 and T3/4a stage tumors in GC, with AUCs of 0.892 (95 %CI: 0.829-0.956), 0.846 (95 %CI: 0.734-0.958), 0.894 (95 %CI: 0.818-0.970) and 0.821 (95 %CI: 0.689-0.952) observed for the training, validation, external test 1, and external test 2 cohorts, respectively. Hosmer-Lemeshow test showed a good fit (all P > 0.05). Decision curves confirmed that the nomogram provided more net clinical benefit than the default simple strategy over a wide range of threshold probabilities.

CONCLUSION

We have developed and validated a multidimensional personalized nomogram that integrates a radiomics model based on DECT-derived IMs, DECT quantitative parameters, and traditional clinical features. The proposed model demonstrated favorable performance in preoperative identification of T3/4a stage tumors in GC.

Clinical implications of micro lymph node metastasis for patients with gastric cancer

BACKGROUND

Lymph node size is considered as a criterion for possible lymph node metastasis in imageology. Micro lymph nodes are easily overlooked by surgeons and pathologists. This study investigated the influencing factors and prognosis of micro lymph node metastasis in gastric cancer.

METHODS

191 eligible gastric cancer patients who underwent D2 lymphadenectomy from June 2016 to June 2017 in the Third Surgery Department at the Fourth Hospital of Hebei Medical University were retrospectively analyzed. Specimens were resected en bloc and the postoperative retrieval of micro lymph nodes was carried out by the operating surgeon for each lymph node station. Micro lymph nodes were submitted for pathological examination separately. According to the results of pathological results, patients were divided into the "micro-LNM (micro lymph node metastasis)" group (N = 85) and the "non micro-LNM" group (N = 106).

RESULTS

The total number of lymph nodes retrieved was 10,954, of which 2998 (27.37%) were micro lymph nodes. A total of 85 (44.50%) gastric cancer patients had been proven to have micro lymph node metastasis. The mean number of micro lymph nodes retrieved was 15.7. The rate of micro lymph node metastasis was 8.1% (242/2998). Undifferentiated carcinoma (90.6% vs. 56.6%, P = 0.034) and more advanced Pathological N category (P < 0.001) were significantly related to micro lymph node metastasis. The patients with micro lymph node metastasis had a poor prognosis (HR for OS of 2.199, 95% CI = 1.335-3.622, P = 0.002). For the stage III patients, micro lymph node metastasis was associated with shorter 5-year OS (15.6% vs. 43.6%, P = 0.0004).

CONCLUSIONS

Micro lymph node metastasis is an independent risk factor for poor prognosis in gastric cancer patients. Micro lymph node metastasis appears to be a supplement to N category in order to obtain more accurate pathological staging.

Multi-modal analysis for accurate prediction of preoperative stage and indications of optimal treatment in gastric cancer

BACKGROUND

Accurate preoperative clinical staging of gastric cancer helps determine therapeutic strategies. However, no multi-category grading models for gastric cancer have been established. This study aimed to develop multi-modal (CT/EHRs) artificial intelligence (AI) models for predicting tumor stages and optimal treatment indication based on preoperative CT images and electronic health records (EHRs) in patients with gastric cancer.

METHODS

This retrospective study enrolled 602 patients with a pathological diagnosis of gastric cancer from Nanfang hospital retrospectively and divided them into training (n = 452) and validation sets (n = 150). A total of 1326 features were extracted of which 1316 radiomic features were extracted from the 3D CT images and 10 clinical parameters were obtained from electronic health records (EHRs). Four multi-layer perceptrons (MLPs) whose input was the combination of radiomic features and clinical parameters were automatically learned with the neural architecture search (NAS) strategy.

RESULTS

Two two-layer MLPs identified by NAS approach were employed to predict the stage of the tumor showed greater discrimination with the average ACC value of 0.646 for five T stages, 0.838 for four N stages than traditional methods with ACC of 0.543 (P value = 0.034) and 0.468 (P value = 0.021), respectively. Furthermore, our models reported high prediction accuracy for the indication of endoscopic resection and the preoperative neoadjuvant chemotherapy with the AUC value of 0.771 and 0.661, respectively.

CONCLUSIONS

Our multi-modal (CT/EHRs) artificial intelligence models generated with the NAS approach have high accuracy for tumor stage prediction and optimal treatment regimen and timing, which could facilitate radiologists and gastroenterologists to improve diagnosis and treatment efficiency.

EFFICACY ANALYSIS OF ENDOSCOPIC SUBMUCOSAL DISSECTION FOR THE EARLY GASTRIC CANCER AND PRECANCEROUS LESIONS

BACKGROUND

Endoscopic treatment of precancerous lesions and early gastric cancer has been widely accepted in recent years. Endoscopic submucosal dissection (ESD), following established indication criteria, can lead to cure of the disease in more than 90% of cases.

OBJECTIVE

This study aimed to analyze the use of ESD in patients with early gastric cancer and precancerous lesions, as well as the results of the procedure, its complications and effectiveness in controlling the disease.

METHODS

This is a retrospective cohort study composed of 41 patients aged from 53 to 87 years (mean age: 65 years; 58.53% male) who were analyzed from 2008 to 2019. The variables collected from the medical records were: comorbidities, classification of the lesion regarding resection criteria, type of resection, histology, degree of invasion, resection margin, complications, disease recurrence. Statistical analysis was performed using the Kruskal-Wallis test, the McNemar's test, and the Mann-Whitney test, with 5% statistical significance (P<0.05).

RESULTS

The most frequent site of the lesion was the gastric antrum and the predominant presentation by the Japanese or Paris classification was the one with depressed components in 56.09%. Adenocarcinoma occurred in 75.6% of the biopsies, and the remainder were adenomas without neoplasia. En-bloc resection occurred in 97.57% of cases, and compromise of the safety margin occurred in one patient. The main pre-existing comorbidity was liver cirrhosis in 29.26% of cases. There was a significant increase in post- ESD adenocarcinoma compared to pre-resection diagnosis. The mean follow-up time was 38.4 months, with one recurrence (2.43%) and two metachronous lesions (4.87%). Complications during and after the procedure occurred in three patients (7.31%), being due to bleeding (two cases) and perforation (one case). There was one death due to a cardiac event not directly related to the procedure.

CONCLUSION

Endoscopic submucosal dissection proved to be a safe procedure, with a low complication and recurrence rate. Its recommendation must occur within the established criteria; however, it can be indicated for patients outside the criteria, if there is a high risk for surgical treatment.

Naples Prognostic Score Predicts Tumor Regression Grade in Resectable Gastric Cancer Treated with Preoperative Chemotherapy

Despite recent progresses, locally advanced gastric cancer remains a daunting challenge to embrace. Perioperative chemotherapy and D2-gastrectomy depict multimodal treatment of gastric cancer in Europe, shows better results than curative surgery alone in terms of downstaging, micrometastases elimination, and improved long-term survival. Unfortunately, preoperative chemotherapy is useless in about 50% of cases of non-responder patients, in which no effect is registered. Tumor regression grade (TRG) is directly related to chemotherapy effectiveness, but its understanding is achieved only after surgical operation; accordingly, preoperative chemotherapy is given indiscriminately. Conversely, Naples Prognostic Score (NPS), related to patient immune-nutritional status and easily obtained before taking any therapeutic decision, appeared an independent prognostic variable of TRG. NPS was calculated in 59 consecutive surgically treated gastric cancer patients after neoadjuvant FLOT4-based chemotherapy. 42.2% of positive responses were observed: all normal NPS and half mild/moderate NPS showed significant responses to chemotherapy with TRG 1-3; while only 20% of the worst NPS showed some related benefits. Evaluation of NPS in gastric cancer patients undergoing multimodal treatment may be useful both in selecting patients who will benefit from preoperative chemotherapy and for changing immune-nutritional conditions in order to improve patient's reaction against the tumor.

2D and 3D CT Radiomic Features Performance Comparison in Characterization of Gastric Cancer: A Multi-Center Study

OBJECTIVE

Radiomics, an emerging tool for medical image analysis, is potential towards precisely characterizing gastric cancer (GC). Whether using one-slice 2D annotation or whole-volume 3D annotation remains a long-time debate, especially for heterogeneous GC. We comprehensively compared 2D and 3D radiomic features' representation and discrimination capacity regarding GC, via three tasks ( T^LNM, lymph node metastasis' prediction; T^LVI, lymphovascular invasion's prediction; T^pT, pT4 or other pT stages' classification).

METHODS

Four-center 539 GC patients were retrospectively enrolled and divided into the training and validation cohorts. From 2D or 3D regions of interest (ROIs) annotated by radiologists, radiomic features were extracted respectively. Feature selection and model construction procedures were customed for each combination of two modalities (2D or 3D) and three tasks. Subsequently, six machine learning models ( Model_2D^LNM, Model_3D^LNM; Model_2D^LVI, Model_3D^LVI; Model_2D^pT, Model_3D^pT) were derived and evaluated to reflect modalities' performances in characterizing GC. Furthermore, we performed an auxiliary experiment to assess modalities' performances when resampling spacing different.

RESULTS

Regarding three tasks, the yielded areas under the curve (AUCs) were: Model_2D^LNM's 0.712 (95% confidence interval, 0.613-0.811), Model_3D^LNM's 0.680 (0.584-0.775); Model_2D^LVI's 0.677 (0.595-0.761), Model_3D^LVI's 0.615 (0.528-0.703); Model_2D^pT's 0.840 (0.779-0.901), Model_3D^pT's 0.813 (0.747-0.879). Moreover, the auxiliary experiment indicated that Models_2D are statistically advantageous than Models_3D with different resampling spacings.

CONCLUSION

Models constructed with 2D radiomic features revealed comparable performances with those constructed with 3D features in characterizing GC.

SIGNIFICANCE

Our work indicated that time-saving 2D annotation would be the better choice in GC, and provided a related reference to further radiomics-based researches.

Survival and adequate preoperative staging in patients undergoing gastric cancer surgery at a Peruvian Police Hospital

INTRODUCTION

Gastric cancer is the fifth most common malignant neoplasm and the third leading cause of cancer-related death worldwide. In Peru, its incidence is 15.8 per 100,000 population, and it is associated with high mortality rates, especially in areas with low socioeconomic status. The aim of this study was to compare preoperative, postoperative, and anatomopathological staging results and their relation to disease recurrence and survival.

METHODS

We conducted a retrospective cohort study of patients undergoing surgery for gastric cancer with a definitive postoperative anatomopathological diagnosis from 2005 to 2014 at the Hospital Nacional Luis N. Sáenz. Statistical analyses included descriptive and correlation statistics using the κ index, determination of associations between preoperative and postoperative staging and surgical reintervention and recurrence using the χ2  test, as well as Kaplan Meier survival analysis.

RESULTS

There was little correlation between preoperative staging and final anatomopathological diagnosis, while there was a good correlation with postoperative staging. A significant association was found between preoperative staging and cancer recurrence. In the survival analysis, survival was lower among patients with underestimated staging.

CONCLUSIONS

The survival of patients with gastric cancer can be affected by an overestimation of preoperative staging, therefore improvements in preoperative staging could lengthen the survival of patients undergoing gastric cancer surgery.

Diagnosis of gastric cancer by MDCT gastrography: diagnostic characteristics and management potential

Background

Gastric cancer is regarded as the fifth most frequent tumor globally but the third most common fatal illness. As early as possible, we diagnose cancer stomach especially at early stages, the higher the rate of life. Nevertheless, most cases are diagnosed at late cases where surgery is not of the same benefit at early stages because of clinically indefinite symptoms. The prospective study goal is to estimate the role of MDCT in diagnosis and staging of cancer stomach.

Results

In our study, it was found that there was a high relationship between pathological and CT staging by using MPR. CT with MPR was specific and accurate in diagnosis of all stages of gastric cancer with specificity ranged between 93 and 97% and accuracy ranged between 90 and 92.5%. However, it showed lowest sensitivity in diagnosis of stage 1 of gastric cancer. On the other hand, it showed highest sensitivity (90%) in diagnosis of stage IV as well as we found that MPR and VR of MDCT are much more accurate (92.5%) than multi-detector computed tomography axial images (80%) in the diagnosis of all stages of gastric cancer with the difference between the two sequences was significant (P = 0.009).

Conclusion

Our results demonstrate that preoperative MDCT with contrast filling technique for abdomen and pelvis evaluates the local disease process of gastric cancer as well as the potential areas of spread. This information is vital in choosing between palliative or radical surgery. MPR and VR help in the assessment of tumor extension and considered as a highly representative prognostic value. Making it the imaging modality of choice in diagnosis and staging of gastric cancers.

Which is the optimal management for locally advanced gastric cancer patients with TRG 0 and 1 after R0 resection?

Background

Neoadjuvant chemotherapy (NAC) followed by surgery currently offers promise as a strategy for patients with locally advanced gastric cancer (GC). However, there is limited evidence to guide treatment for TRG 0 and 1 patients with locally advanced GC after R0 resection. This study set out to explore the optimal management for TRG 0 and 1 patients with locally advanced GC after R0 resection.

Methods

The retrospective data of 154 TRG 0 and 1 patients with locally advanced GC following R0 resection who were treated between January 2012 and December 2018 were collected and analyzed. The Kaplan-Meier method was used to estimate the survival rate. Multivariate analysis was performed using the Cox proportional hazards model.

Results

The median follow-up was 34.1 (range, 6.6–90.9) months. Six patients (3.9%) were lost during follow-up. Of the 27 patients who experienced relapse, 12 died, including 2 patients who died of non-neoplastic causes. The 5-year recurrence-free survival (RFS) and 5-year overall survival (OS) were 71.6% (95% CI: 68.5–79.6) and 82.9% (95% CI: 76.9–86.1) for the whole cohort, respectively. Univariate analysis revealed that patients with carcinoembryonic antigen (CEA) <5.0 ng/ml after NAC (77.7% vs. 20.1%, P<0.001), distal gastrectomy (91.7% vs. 67.5%, P=0.046) had higher 5-year RFS. Meanwhile, combined resection (55.6% vs. 73.1%, P=0.042), major complications (42.7% vs. 80.50%, P<0.001), and lymph node metastasis (ypN+) (52.0% vs. 83.7%, P<0.001) had lower 5-year RFS. The multivariate analysis showed that CEA level after NAC (HR =2.876, 95% CI: 1.051–7.872, P=0.040), major complications (HR =2.432, 95% CI: 1.062–5.567, P=0.035), and lymph node metastasis (ypN+) (HR =3.183, 95% CI: 1.242–8.161, P=0.016) were independent prognostic factors.

Conclusions

TRG 0 and 1 patients with local GC after R0 resection following NAC had a good prognosis, especially patients with CEA <5.0 ng/mL after NAC, and those without major complications or lymph node metastasis. Monotherapy or no chemotherapy may offer options for treating TRG 0 and 1 patients without adverse prognostic factors.

FKBP10 Acts as a New Biomarker for Prognosis and Lymph Node Metastasis of Gastric Cancer by Bioinformatics Analysis and in Vitro Experiments

Purpose

To explore the role of FKBP prolyl isomerase 10 (FKBP10) protein in the progression of gastric cancer.

Methods

Four independent gastric cancer databases (GSE27342, GSE29272, GSE54129 and TCGA-STAD) were used to identify differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was used to identify the abnormally active pathways in patients with gastric cancer. Univariate Cox regression analysis was used to identify genes with stable prognostic value in gastric cancer patients based on three independent gastric cancer databases (GSE15459, GSE62254, TCGA-STAD). Gene set enrichment analysis (GSEA) was used to explore the possible pathways related to FKBP10. The reverse transcription-polymerase chain reaction (RT-PCR) was employed to determine the expression of FKBP10 mRNA in the HGC-27 and MKN-7 cell lines. Adhesion assay was used to detect changes in cell adhesion ability. FKBP10, ITGA1, ITGA2, ITGA5, ITGAV, ITGA6, P-AKT₄₇₃, P-AKT₃₀₈, AKT, and β-actin were evaluated by Western blot (WB).

Results

We first performed differential expression genes (DEGs) screening of four independent GC databases (GSE27342, GSE29272, GSE54129 and TCGA-STAD). Eighty-nine genes showed consistent up-regulation in GC, the results of pathway analysis showed that they were related to “Focal adhesion”. The prognostic value of these 89 genes was tested in three independent GC databases GSE15459, GSE62254 and TCGA-STAD cohort. Finally, 12 genes, in which the expression of FKBP10 was prominently increased in patients with lymph node metastasis (LNM), showed stable prognostic value. The following gene set enrichment analysis (GSEA) also showed that FKBP10 is mainly involved in cell adhesion process, while adhesion experiments confirmed that cell adhesion was down-regulated after silencing FKBP10 in GC cells, and adhesion-related molecules integrin αV and α6 were down-regulated.

Conclusion

FKBP10 may be used as a marker for lymph node metastasis of GC and could be used as a potential target for future treatment of GC.

Preoperative Staging of Gastric Cancer Using Computed Tomography and Its Correlation with Histopathology with Emphasis on Multi-planar Reformations and Virtual Gastroscopy

BACKGROUND

Gastric cancer is the fifth most common cancer in the world. Preoperative staging of gastric cancer has assumed pivotal role in deciding appropriate management of gastric cancer with multi-detector computed tomography (MDCT) using hydro- and gaseous distension of stomach superseding endoscopic ultrasound in tumor (T) and nodal (N) staging. We undertook this study to evaluate the diagnostic accuracy of MDCT in the T and N staging of gastric cancer with an attempt to differentiate between early and advanced gastric carcinomas.

METHODS

A total of 160 patients with endoscopically diagnosed and biopsy-proven gastric cancer were subjected to MDCT after adequate gaseous and hydro-distention of stomach. Multi-planar reformatted (MPR) as well as virtual gastroscopy images were also obtained. Gastric lesions were categorized into T1 to T4 stages with N staging from N0 to N3. Preoperative CT findings were correlated with histopathological findings.

RESULTS

Overall diagnostic accuracy of T staging in our study was 82.5% (132/160) with an accuracy of 75% (120/160) for N staging. The diagnostic accuracy of CT for early gastric carcinoma in our study was 93.75% with high specificity of 96% but low sensitivity of 66.7%.

CONCLUSION

MDCT using gaseous and hydro-distension of stomach is an excellent modality for near accurate preoperative T staging of gastric cancer. However, CT has a limited role in the N staging of gastric cancer. This study also suggested that the combined use of virtual gastroscopy and MPR images helps in better detection of early gastric cancers.

Significance of Gastric Wall Thickening Detected in Abdominal CT Scan to Predict Gastric Malignancy

BACKGROUND

Early diagnosis of gastric cancer is one of the most important parameters affecting the survival of the disease. In this study, we aimed to stress the importance of antrum wall thickness in CT examination.

METHOD

The study included 111 patients between ages of 18 and 95 who had antral wall thickening in computed tomography and also had endoscopic evaluation performed in the same clinic. The patients were divided into two groups as benign and malignant according to the pathology results. The thickness of the antrum wall in computed tomography, hemoglobin and albumin levels, and age was compared among these two groups. Parameters with significant differences were further analyzed by multivariate analysis using logistic regression analysis.

RESULTS

Of the 111 patients included in the study, 57 were male and 54 were female. Mean age was 65 years. Fifty-one patients were classified as benign and 60 patients as malignant. Mean age of the malignant patients was 70, while that of benign patients was 59 (p < 0.05). Antrum wall thickness was 13.68 ± 3.27 mm in malignant patients and 9.22 ± 2.17 mm in benign patients (p < 0.05). Similarly, hemoglobin level was significantly different in malignant and benign patients (10.78 ± 1.57 g/dl and 12.64 ± 1.43 g/dl, respectively; p < 0.05). Albumin levels were 3.36 ± 0.57 mg/dl in malignant patients and 3.97 ± 0.57 mg/dl in benign patients (p < 0.05).

CONCLUSION

Evaluation of antrum wall thickness, age, hemoglobin, and albumin values together may contribute to distinguishing the benign and malignant pathologies involving this region in patients with suspected stomach wall thickening in abdominal CT scan.

Cellular magnetic resonance imaging: in vivo tracking of gastric cancer cells and detecting of lymph node metastases using microparticles of iron oxide in mice

Background

Monitoring the fate of implanted cells over time in an experimental animal may provide a new way to track the metastatic process. Lymph node metastase is of extremely importance for the prognostic prediction of gastric carcinoma. The aim of this study was to assess the feasibility of magnetic resonance imaging (MRI), using micron-sized superparamagnetic iron oxide particles (MPIO), for monitoring of the fate of gastric cancer cells and detecting the migration of gastric cancer cells through the lymphatic system in a mouse model.

Methods

SGC-7901 gastric cancer cells were labeled with green fluorescent MPIO. The cells were monitored in vitro at multiple time points by staining for iron-labeled cells and by flow cytometric detection of the fluorescent MPIO. MPIO-labeled cells were implanted subcutaneously into nude mice, and cellular MRI was performed at different time points until 35 days postinjection.

Results

The potential for retention of the iron particles in vitro was evaluated. Our results showed that the labeling and uptake efficiency of MPIO reached 90.0% after 24 hrs of incubation, and a small percentage of cells that retained MPIO could be examined until 16 days after labeling. In vivo MRI-based tracking over several weeks in mice revealed regions of signal loss in the primary tumors for up to 5 weeks. Furthermore, small regions of signal void were detected in images of the inguinal lymph nodes in three mice at day 28 postinjection or later, and histological assays confirmed the presence of iron-labeled cancer cells.

Conclusion

This study supports MPIO-based cell tracking is a useful tool for monitoring the fate of gastric cancer cells in mice over time, which may facilitate progress in understanding the mechanisms of early regional lymph node micrometastases.

Predictive values of multidetector-row computed tomography combined with serum tumor biomarkers in preoperative lymph node metastasis of gastric cancer

OBJECTIVE

Multidetector-row computed tomography (MDCT) and serum tumor biomarkers are commonly used to evaluate the preoperative lymph node metastasis and the clinical staging of gastric cancer (GC). This study intends to evaluate the clinical predictive value of MDCT and serum tumor biomarkers in lymph node metastasis of GC.

METHODS

The clinicopathologic data of 445 GC patients who underwent radical gastrectomy were retrospectively analyzed to evaluate the diagnostic value of MDCT and serum tumor biomarkers in lymph node metastatic staging of GC before surgery.

RESULTS

With the multinomial logistic regression analysis, the independent relative factors of lymph node metastasis of GC were identified as tumor size, depth of tumor invasion, vessel invasion, vascular embolus, and soft tissue invasion. The optimal critical value of the short diameter of lymph nodes detected by MDCT scanning for evaluation of preoperative lymph node metastasis was 6.0 mm, with 75.7% as predictive accuracy of lymph node metastasis compared to the postoperative pathological results of GC patients. In addition, the critical value of the short diameter of lymph nodes combined with serum tumor biomarkers [including carbohydrate antigen (CA)-724 and CA-199] could show an enhancement of predictive sensitivity of lymph node metastasis (up to 89.3%) before surgery.

CONCLUSIONS

MDCT combined with serum tumor biomarkers should be adopted to improve preoperative sensitivity and accuracy of lymph node metastasis for GC patients.

Application of spectral CT imaging in evaluating lymph node metastasis in patients with gastric cancers: initial findings

BACKGROUND

Traditional computed tomography (CT) can predict the lymph node metastasis of gastric cancers with moderate accuracy; however, investigation of spectral CT imaging in this field is still limited.

PURPOSE

To explore the application of spectral CT imaging in evaluating lymph node metastasis in patients with gastric cancers.

MATERIAL AND METHODS

Twenty-four patients with gastric cancers prospectively underwent spectral CT imaging in the arterial phase. The short and long diameters, material concentrations, and CT values were measured and compared between lymph nodes with and without metastasis. The diagnostic performance of the CT index in identifying metastatic lymph nodes was analyzed with receiver operating characteristic (ROC) analysis.

RESULTS

A total of 102 lymph nodes (77 metastatic, 25 non-metastatic) were detected on spectral CT imaging with the reference of postoperative pathologic exanimation. The short and long diameters, water/fat concentrations, CT value, and ratio between lymph nodes vs. tumors of metastatic lymph nodes were significantly higher than those of non-metastatic ones (all P < 0.05). With a cut-off of 0.785, the CT ratio of lymph node/tumor on 70-keV monochromatic images yielded an accuracy of 81.4% in differentiating lymph nodes with and without metastasis.

CONCLUSION

Spectral CT imaging detects lymph nodes more clearly, and the CT ratio of lymph node/tumor on 70-keV monochromatic images holds great potential in differentiating lymph nodes with and without metastasis, which is more accurate than size measurement.

Computed tomography with a stomach protocol and virtual gastroscopy in the staging of gastric cancer: an initial experience

Objective

To evaluate the accuracy of multidetector computed tomography with a stomach protocol in staging of gastric cancer.

Materials and Methods

We evaluated 14 patients who underwent computed tomography in a 16-channel scanner for preoperative staging of gastric adenocarcinoma between September 2015 and December 2016. All images were analyzed by the same radiologist, who had extensive experience in abdominal cancer imaging. The sensitivity, specificity, and accuracy of the method were calculated by comparing it with the pathology result. All patients underwent partial or total gastrectomy.

Results

The mean age was 61.5 years, and 53.8% of the patients were male. The gastric lesions were classified as T1/T2 in 35.7% of the cases, as T3 in 28.5%, and as T4 in 35.7%. Eleven patients (68.7%) had suspicious (N positive) lymph nodes. The accuracy of the T1/T2, T3, T4, and lymph node staging tests was 85%, 78%, 90%, and 78%, respectively. The respective sensitivity and specificity values were 71% and 100% for T1/T2, 66% and 81% for T3, 100% and 90% for T4, and 88% and 60% for lymph nodes.

Conclusion

Multidetector computed tomography with a stomach protocol, used in conjunction with virtual gastroscopy, shows good accuracy in the tumor and lymph node staging of gastric adenocarcinoma.

Is Accurate N - Staging for Gastric Cancer Possible?

Node stage (N stage) is of paramount importance for gastric cancer staging. Radiologically node status implies detection and characterization of suspect malignant lymph nodes. Clinically it might determine survival and alter therapeutic plans. A number of modalities, including computerized tomography, MRI, PET and endoscopic ultrasound are currently available. Using a multimodality strategy, accuracy ranges between 50-90% across various studies. Specificity and sensitivity varies with respect to method, number of positive lymph nodes, their location and other characteristics. Restaging after neoadjuvant therapy and staging of recurrence presents its own, particular challenges. Each method has its advantages and limitations and none of them alone is adequate enough for staging. While most of them are clinically well established, they are also active research topics. To overcome the aforementioned limitations a multidisciplinary, multimodality approach with emphasis on clinical staging and treatment plans is proposed.

Transabdominal Ultrasonography for Assessing the Depth of Tumor Invasion in Gastric Cancer

BACKGROUND

Although endoscopy and endoscopic ultrasonography are generally used to diagnose the depth of gastric tumor invasion, endoscopy is invasive and frequently results in patient discomfort. Transabdominal ultrasonography (TUS) is noninvasive and may be useful in determining this depth. We investigated the usefulness of TUS in determining the depth of tumor invasion in patients with gastric cancer.

METHODS

This retrospective study included 190 patients with gastric cancer and 200 lesions who underwent curative resection at the Department of Gastrointestinal Surgery of Tottori University Hospital from July 2007 to July 2015. The results of conventional diagnostic imaging and TUS were compared with those of pathological analysis obtained after surgery. Furthermore, the ruptured form of the third layer on TUS imaging was reviewed and investigated to differentiate between the SM2 and MP lesions.

RESULTS

The accuracy of TUS was similar to that of conventional diagnostic imaging for all depths of tumor invasion. Eight lesions could not be assessed by TUS, including four that could not be identified and four in which TUS was unable to diagnose the depth. In cases where the ruptured form of the third layer could be determined in MP lesions, the forms were observed toward the inside of the gastric lumen.

CONCLUSION

The results of this study suggested that the accuracy of TUS was equivalent to that of conventional diagnostic imaging in determining the depth of tumor invasion. TUS assessment criteria may be useful to classify this depth. Furthermore, the ruptured form of the third layer is believed to be important in distinguishing between early and advanced gastric cancer.

Endoscopic ultrasonography compared with multidetector computed tomography for the preoperative staging of gastric cancer: a meta-analysis

Background

The current study sought to perform a meta-analysis to compare the preoperative staging of endoscopic ultrasonography (EUS) and multidetector computed tomography (MDCT) in gastric carcinoma.

Methods

Articles published between January 1, 2000, and April 1, 2016, that compared EUS with MDCT were included, and data were presented as 2 × 2 tables. The sensitivities, specificities and summary receiver operating characteristic (ROC) curves for T and N staging were calculated using a bivariate mixed effects model. Data were weighted by generic variance and then pooled by random-effects modeling.

Results

Eight studies comprising 1736 patients were included in this meta-analysis. For T1 staging, the sensitivity value for EUS (82%) was significantly higher than that for MDCT (41%) (relative risk (RR): 2.06, 95% confidence interval (CI) 1.07–3.94; P = 0.030). For lymph node involvement, the sensitivity value for EUS (91%) was also significantly higher than that for MDCT (77%) (RR 1.14, 95% CI 1.05–1.23; P = 0.001). However, the specificity values of both EUS and MDCT were quite low, at 49 and 63%, respectively. No significant differences in T2–4 staging between EUS and MDCT were noted.

Conclusion

This meta-analysis indicates that EUS may be superior to MDCT in preoperative T1 and N staging. Additionally, the low specificity values of EUS and MDCT for N staging merits attention.

Abdominal vascular syndromes: characteristic imaging findings

Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital-including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)-or compressive-including "nutcracker" syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic.

Defecography by digital radiography: experience in clinical practice

Objective

The objective of this study was to profile patients who undergo defecography, by age and gender, as well as to describe the main imaging and diagnostic findings in this population.

Materials and Methods

This was a retrospective, descriptive study of 39 patients, conducted between January 2012 and February 2014. The patients were evaluated in terms of age, gender, and diagnosis. They were stratified by age, and continuous variables are expressed as mean ± standard deviation. All possible quantitative defecography variables were evaluated, including rectal evacuation, perineal descent, and measures of the anal canal.

Results

The majority (95%) of the patients were female. Patient ages ranged from 18 to 82 years (mean age, 52 ± 13 years): 10 patients were under 40 years of age; 18 were between 40 and 60 years of age; and 11 were over 60 years of age. All 39 of the patients evaluated had abnormal radiological findings. The most prevalent diagnoses were rectocele (in 77%) and enterocele (in 38%). Less prevalent diagnoses were vaginal prolapse, uterine prolapse, and Meckel's diverticulum (in 2%, for all).

Conclusion

Although defecography is performed more often in women, both genders can benefit from the test. Defecography can be performed in order to detect complex disorders such as uterine and rectal prolapse, as well as to detect basic clinical conditions such as rectocele or enterocele.