Comparison of hydro-US and spiral CT in the staging of gastric cancer

Radiomics analysis based on CT's greater omental caking for predicting pathological grading of pseudomyxoma peritonei

The objective of this study was to predict the preoperative pathological grading and survival period of Pseudomyxoma peritonei (PMP) by establishing models, including a radiomics model with greater omental caking as the imaging observation index, a clinical model including clinical indexes, and a combined model of these two. A total of 88 PMP patients were selected. Clinical data of patients, including age, sex, preoperative serum tumor markers [CEA, CA125, and CA199], survival time, and preoperative computed tomography (CT) images were analyzed. Three models (clinical model, radiomics model and combined model) were used to predict PMP pathological grading. The models’ diagnostic efficiency was compared and analyzed by building the receiver operating characteristic (ROC) curve. Simultaneously, the impact of PMP’s different pathological grades was evaluated. The results showed that the radiomics model based on the CT’s greater omental caking, an area under the ROC curve ([AUC] = 0.878), and the combined model (AUC = 0.899) had diagnostic power for determining PMP pathological grading. The imaging radiomics model based on CT greater omental caking can be used to predict PMP pathological grading, which is important in the treatment selection method and prognosis assessment.

The Value of Computed Tomography in Preoperative N Staging of Early Gastric Cancer Meeting the Endoscopic Resection Criteria

Background/Aims

This study evaluated the value of abdominal computed tomography (CT) in preoperative N staging of early gastric cancers (EGCs) within standard and expanded indications of endoscopic resection (ER) and investigated the factors affecting accuracy.

Methods

Between March 2009 and March 2016, a total of 268 patients with EGC within the standard and expanded indications of ER underwent preoperative abdominal CT and surgical gastrectomy with lymph node (LN) dissection. Preoperative N staging of CT was compared with the pathologic result.

Results

The accuracy of N staging for EGCs within the standard and expanded indications was 86.1% (235/268). There was no LN metastasis in patients with cN1 in CT staging. LN metastasis was found in 7 patients with EGCs that met the expanded ER indication and cN0 in CT staging. According to the univariate analysis, ulcers, including scars, were associated with the false positive of lymph node metastasis in abdominal CT (odds ratio 3.56; 95% confidence interval 1.56-8.15).

Conclusions

The present study suggests that the value of abdominal CT is limited for nodal staging of EGCs that meet the ER indication.

Enhanced intensity on preoperative double contrast-enhanced sonography as a useful indicator of lymph node metastasis in patients with gastric cancer

OBJECTIVES

The aim of this study was to investigate the predictive value of enhanced intensity on double contrast-enhanced sonography in assessing lymph node metastasis of gastric cancer.

METHODS

A total of 357 patients with gastric cancer were enrolled in this study. Double contrast-enhanced sonography, in which an oral ultrasound contrast agent is combined with an intravenous contrast agent, was performed preoperatively, and the data were analyzed quantitatively. The predictive ability of enhanced intensity, a quantitative double contrast-enhanced sonographic measure, for lymph node metastasis was evaluated retrospectively.

RESULTS

Compared to negative lymph node metastasis cases, the presence of thicker lesions, deeper invasion, poorer differentiation, and higher enhanced intensity were found in positive cases (P< .05). An enhanced intensity cutoff value of 16.91 dB was the best point for balancing the sensitivity and specificity (71.50% and 79.30%, respectively) for prediction of lymph node metastasis, with the highest Youden index of 0.508. The area under the receiver operating characteristic curve was 0.828 (P < .001; 95% confidence interval, 0.786-0.870). In cases in which the lesions were hyperenhanced (enhanced intensity >16.91 dB), the lesions were significantly thicker and had deeper invasion, poorer differentiation, and more positive metastasis findings compared to non-hyperenhanced cases (enhanced intensity ≤16.91 dB; P < .05). On logistic regression analysis, the enhanced intensity of primary tumors and the invasion depth were significantly associated with lymph node metastasis.

CONCLUSIONS

Double contrast-enhanced sonography with quantitative analysis may be considered a novel alternative imaging modality for noninvasive preoperative evaluation of lymph node metastasis with good reliability.

Histological complete response to a combined docetaxel/cisplatin/fluorouracil neoadjuvant chemotherapy for T4 stage gastric adenocarcinoma

Local advanced gastric carcinoma has a very poor prognosis. When a T4 gastric carcinoma has invaded the surrounding tissues and organs, curative resection is unlikely. We present here a case of a 63-year-old woman with a T4 unresectable gastric adenocarcinoma. She underwent two 3-week cycles of docetaxel/cisplatin/fluorouracil chemotherapy, followed by radical gastric resection. Each cycle consisted of 75 mg/m² docetaxel and 75 mg/m² cisplatin on day 1, and 200 mg/m² leucovorin and 500 mg/m² fluorouracil on days 1 through 5. The patient exhibited a complete histologic response. Our results indicate that docetaxel/cisplatin/fluorouracil neoadjuvant chemotherapy is a promising method of treatment for advanced 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 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.

Efficacy of hydrogastric sonography and spiral Computed Tomography in staging of gastric carcinoma--a comparative study

OBJECTIVE

Accurate preoperative diagnosis and staging of patients with gastric cancer is essential for optimal treatment. The standard of care for staging gastric carcinoma is helical CT. This study was conducted to compare the efficacy of hydrogastric sonography (HGS) with that of helical CT in the staging of patients with gastric carcinoma.

METHODS

A total of 42 consecutive patients (29 men and 13 women) diagnosed with gastric carcinoma after endoscopy and biopsy were staged on the basis of TNM classification, preoperatively with HGS and helical CT and postoperatively with histopathologic examination (HPE). The findings of HGS and helical CT were compared with those on HPE with respect to TNM stage.

RESULTS

Regarding T stage, the accuracy of HGS was 78.6% (kappa = 0.68) and that of helical CT was 66.7% (kappa = 0.48). In evaluating the nodal status, the accuracy of HGS was 66.7% (kappa = 0.52) and that of helical CT was 54.6% (kappa = 0.39). Regarding distant metastases, accuracy was the same with HGS and helical CT (accuracy 95.2%, kappa = 0.89).

CONCLUSIONS

When compared with HPE, HGS was found to be more accurate than helical CT for assessment of T and N staging. Sonographic and helical CT were equally accurate for the assessment of M stage.

Hydrosonography of the gastrointestinal tract

OBJECTIVE

Bowel sonography has become accepted as a useful tool in several gastrointestinal disorders. Filling of the gut with echo-poor liquids has been proposed to achieve a detailed evaluation of the bowel. This article refers to a review made concerning the benefits and limits of hydrosonography of the gastrointestinal tract.

CONCLUSION

The use of a luminal contrast agent in bowel sonography may improve results but should be adopted on a case-by-case basis, according to the clinical context and the experience of the sonologist.

Preoperative T staging of gastric carcinoma obtained by MDCT vessel probe reconstructions and correlations with histological findings

This study aims to evaluate the diagnostic accuracy of 16-row multidetector CT (MDCT) and vessel probe reconstructions in the T staging of gastric carcinoma. Fifty-three patients (39 men, 14 women, mean age 57.5) with an endoscopic diagnosis of gastric adenocarcinoma underwent CT examination. A hypotonic drug was administered, and the gastric walls were distended by the ingestion of 400-600 ml of water. A biphasic technique with 40-s and 70-s delay was used after endovenous contrast material injection. All patients underwent surgery, and preoperative and histological stagings were compared. The diagnostic accuracy of T staging was 68% for axial images and 94% for VP reconstructions. In the T1, T2, T3 and T4 parameter evaluation, diagnostic accuracy values were 87%, 73.5%, 81% and 96%, respectively, for axial images and 96%, 96%, 98% and 100%, respectively for VP reconstructions. MDCT is an accurate technique for the preoperative staging of gastric cancer. The VP reconstructions obtained by isotropic data can evaluate the T parameter with a higher accuracy.

Imaging in assessing lymph node status in gastric cancer

BACKGROUND

Accurate assessment of lymph node status is of crucial importance for appropriate treatment planning and determining prognosis in patients with gastric cancer. The aim of this study was to systematically review the current role of imaging in assessing lymph node (LN) status in gastric cancer.

METHODS

A systematic literature search was performed in the PubMed/MEDLINE and Embase databases. The methodological quality and diagnostic performance of the included studies was assessed.

RESULTS

Six abdominal ultrasonography (AUS) studies, 30 endoscopic ultrasonography (EUS) studies, 10 multidetectorrow computed tomography (MDCT) studies, 3 conventional magnetic resonance imaging (MRI) studies, 4 (18)F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) studies, and 1 FDG-PET/CT fusion study were included. In general, the included studies had moderate methodological quality. The sensitivity and specificity of AUS varied between 12.2% and 80.0% (median, 39.9%) and 56.3% and 100% (median, 81.8%). The sensitivity and specificity of EUS varied between 16.7% and 95.3% (median, 70.8%) and 48.4% and 100% (median, 84.6%). The sensitivity and specificity of MDCT varied between 62.5% and 91.9% (median, 80.0%) and 50.0% and 87.9% (median, 77.8%). The sensitivity and specificity of MRI varied between 54.6% and 85.3% (median, 68.8%) and 50.0% and 100% (median, 75.0%). The sensitivity and specificity of FDG-PET varied between 33.3% and 64.6% (median, 34.3%) and 85.7% and 97.0% (median, 93.2%). The sensitivity and specificity of the FDG-PET/CT fusion study were 54.7% and 92.2%. For all the imaging modalities, there were no significant differences between the mean sensitivities and specificities of high- and low-quality studies.

CONCLUSION

AUS, EUS, MDCT, conventional MRI, and FDG-PET cannot reliably be used to confirm or exclude the presence of LN metastasis. The performance of highresolution PET/CT fusion and functional MRI techniques still has to be determined.

Thickening of the gastric wall on transabdominal sonography: a sign of gastric cancer

PURPOSE

To determine the value of a thickened gastric wall detected during transabdominal sonography (TAS) in the diagnosis of gastric cancer.

METHOD

This prospective study comprised 312 patients who underwent both TAS and endoscopy. Transverse TAS scanning was performed using a 3.5-MHz curved transducer to measure gastric wall thickness in the antrum and body of the stomach. Based on endoscopic and histologic findings, we classified the patients into 3 groups: normal or benign disease (BD), early gastric cancer (EGC), and advanced gastric cancer (AGC). TAS findings were then compared.

RESULTS

The thickness of the gastric wall was 4.9 +/- 1.6 mm in 262 patients with BD, 5.6 +/- 2.4 mm in 21patients with EGC, and 10.3 +/- 4.7 mm in 29 patients with AGC (p < 0.01). A gastric wall thickness of greater than 7 mm had a 75.0% sensitivity, 92.6% specificity, 50.0% positive predictive value, and 97.4% negative predictive value in the diagnosis of AGC.

CONCLUSION

Although not suitable as a screening method for gastric cancer, a thickening of the gastric wall of >7 mm may be a marker for AGC.

64 multidetector-row computed tomography for preoperative evaluation of gastric cancer: histological correlation

OBJECTIVE

To assess the accuracy of 64 multidetector-row computed tomography (MDCT) in the diagnosis and staging of gastric cancer.

METHODS

This study was approved by the institutional review board, and the patients involved gave informed consent. Forty-four patients (34 men and 10 women; mean age, 57 years) with gastric carcinoma underwent preoperative 64 MDCT (SOMATOM Sensation 64; Siemens Medical System, Forchheim, Germany; slice collimation, 0.6 mm; slice width, 5 mm; feed/rotation, 23 mm; pitch factor, 1.2; kernel, B30f; and gantry speed, 0.5 second per rotation). Gastric distension was achieved by ingestion of 8 g of effervescent granules. Scanning was performed during arterial and portal phases, as determined with bolus tracking and automated triggering technique after intravenous administration of 100 mL of contrast materials (4 mL/s). All computed tomography scans were retrospectively reviewed by 2 radiologists. Each tumor was staged according to the TNM classification system. All patients underwent surgery. Computed tomography results were compared with histological staging of tumor invasion depth and regional lymph node metastasis.

RESULTS

The accuracy of 64 MDCT for detection of gastric cancer was 90% (18/20) and 100% (24/24) in early and advanced gastric cancer, respectively, with an overall detection rate of 95% (42/44). Its accuracy for determination of tumor penetration depth was 89% (16/18) and 88% (21/24) in early and advanced gastric cancer, respectively, with an overall accuracy of 88% (37/42). Its accuracy for determination of lymph node metastasis was 90% (18/20) and 71% (17/24) in early and advanced gastric cancer, respectively, with an overall accuracy of 80% (35/44).

CONCLUSIONS

The 64 MDCT is a promising technique for the detection and preoperative staging of gastric cancer.

Evaluation of contrast-enhanced helical hydro-CT in staging gastric cancer

AIM: To discuss the helical computed tomography (CT) characteristics of gastric cancer and evaluate the diagnostic value of contrast-enhanced helical hydro-CT (HHCT) in staging gastric cancer.

METHODS: A total of 50 patients with gastric cancer were included in this study. The CT findings in them were retros-pectively analyzed and correlated with pathologic findings at surgery. All patients were preoperatively imaged by plain and contrast-enhanced helical CT after orally ingesting 1 000-1 500 mL water. Peristalsis was minimized by intra-venous administration of spasmolytics.

RESULTS: The foci of gastric cancer became more prominent in all the 50 patients and showed strong enhancement in contrast-enhanced HHCT. The tumor was located at the gastric cardia in 14 cases, at the gastric fundus in 3 cases, at the gastric body in 8 cases, at the gastric antrum in 4 cases, at the gastric fundus and the body in 8 cases, at the gastric body and antrum in 11 cases, and at three segments of the stomach in 2 cases. The CT features of gastric cancer were focal or diffuse mural thickening, soft tissue mass, cancerous ulcer, stenosis of stomach, infiltration to adjacent tissues, lymph node and distant metastases. Strong contrast enhancement of the gastric wall was closely related to gastric cancer. The accuracy rate of contrast-enhanced HHCT in staging gastric cancer was 86% (43/50). The detection rate of lymph node metastases by CT was 60% (12/20).

CONCLUSION: Contrast-enhanced HHCT is a reliable method to diagnose and stage gastric cancer.