Three-dimensional MDCT Gastrography Compared With Axial CT for the Detection of Early Gastric Cancer

Utility of the gastric window in computed tomography for differentiation of early gastric cancer (T1 stage) from muscularis involvement (T2 stage)

OBJECTIVE

To analyze the diagnostic value of using the gastric window in computed tomography for differentiation of early gastric cancer (T1 stage) from muscularis involvement (T2 stage).

MATERIALS AND METHODS

All patients with pathologically confirmed T1 stage and T2 stage gastric cancer and who underwent endoscopic resection or gastrectomy at our institution from January 2011 to November 2018 were examined. Each patient received an enhanced CT scan of the abdomen before the operation. T staging of tumors based on the CT scans was performed independently by two radiologists using the gastric window (width 150-200 HU, level 80-100 HU) and the abdominal window (width 350-400 HU, level 50 HU).

RESULTS

Use of the gastric window to diagnose stage T1 EGC led to an accuracy of 88.9% for observer1 and 91.5% for observer2; use of the abdominal window led to an accuracy of 53.6% for observer1 and 51.6% (38/106) for observer2. Use of the gastric window to diagnose stage T2 led to an accuracy of 85.6% for observer1 and 82.4% for observer2; use of the abdominal window led to an accuracy of 52.3% for both observer1 and observer2. For observer1, use of the gastric window had a diagnostic accuracy of 69.2% for stage T1a and 62.5% for stage T1b; for observer2, the diagnostic accuracy was 65.1% for stage T1a and 67.0% for stage T1b. A Kappa test indicated moderate and substantial inter-observer agreement for T staging with gastric window (κ = 0.598, P < 0.001) and abdominal window (κ = 0.745, P < 0.001).

CONCLUSION

Use of the gastric window in computed tomography provided more accurate staging for T1 and T2 stages of gastric cancer than the conventional abdominal window.

Three-dimensional fusion images combining CT gastrography and CT angiography for early gastric cancer: pilot experiences of preoperative simulation prior to totally laparoscopic gastrectomy

We herein report two cases of gastric cancer in which preoperative 3-D CT gastrography and CT angiography fusion images enabled totally laparoscopic gastrectomy. Case 1 involved a 60-year-old woman with a superficial depressed lesion on the greater curvature of the middle gastric body. Case 2 involved a 64-year-old woman with a superficial depressed lesion on the posterior wall of the upper gastric body. In both cases, 3-D fusion images were prepared from enhanced CT scans after the area near the lesions was clipped under preoperative gastroendoscopy. Based on the relative position between the clips and nearby vessels, a resection line was preoperatively determined in each case. Totally laparoscopic distal gastrectomy and totally laparoscopic proximal gastrectomy were performed in cases 1 and 2, respectively, with safe surgical margins. Three-dimensional fusion images can help in preoperative simulation of totally laparoscopic gastrectomy.

Gastric cancer detection using MDCT compared with 2D axial CT: diagnostic accuracy of three different reconstruction techniques

PURPOSE

To assess the diagnostic accuracy of different reconstruction techniques using MDCT for gastric cancer detection compared with 2D axial CT.

MATERIALS AND METHODS

During 7 months, we performed CT examinations of 104 consecutive patients with gastric cancer and of a control group composed of 35 patients without gastric disease. All gastric cancer was pathologically proven by endoscopy and surgery. Among 104 patients with gastric cancer, 63 patients had early gastric cancer (EGC). Two radiologists retrospectively and independently interpreted the axial CT and three different reconstruction techniques including multiplanar reformation (MPR), transparent imaging (TI), and virtual gastroscopy (VG), using a commercially available, 3D workstation. They graded the presence or absence of gastric cancer in each image sets using a five-point scale and, if present, they assessed its location. Diagnostic accuracy was compared using the area under the receiver operating characteristic curve (Az) for both gastric cancer and only EGC. Sensitivity and specificity were also calculated for each image technique. The k statistics were used to determine inter-observer agreement.

RESULTS

The diagnostic accuracy for overall gastric cancer detection for each of the image sets was as follows: 2D axial CT (Az = 0.858); MPR (Az = 0.879); TI (Az = 0.873); and VG (Az = 0.928). VG had significantly better performance than 2D axial CT (p = 0.016). The sensitivity and specificity were as follows: 76.7% and 82.9% in axial CT; 79.6% and 85.7% in MPR; 91.3% and 80% in TI; and 95.1% and 74.3% in VG. In EGC, the diagnostic performance for its detection was as follows: axial CT (Az = 0.777); MPR (Az = 0.811); TI (Az = 0.825); and VG (Az = 0.896). VG had significantly better performance than both 2D axial CT (P = 0.006) and MRP (P = 0.038). The sensitivity and specificity were as follows: 62.9% and 82.9% in axial CT; 67.7% and 85.7% in MPR; 85.5% and 80% in TI; and 91.9% and 74.3% in VG. The inter-observer agreement showed substantial agreement (κ = 0.67-0.75).

CONCLUSION

Among the different reconstruction techniques, VG accurately detects gastric cancer and is especially useful for EGC compared with 2D axial CT.

Clinical application of immune-enhanced enteral nutrition in patients with advanced gastric cancer after total gastrectomy

OBJECTIVE

To determine whether immune-enhanced enteral nutrition (EN) was effective on nutritional status, immune function, surgical outcomes and days of hospitalization after total gastrectomy for patients with advanced gastric cancer (AGC).

METHODS

From August 2005 to May 2011, 78 patients with AGC who underwent a total gastrectomy were enrolled and divided randomly into three groups: immune-enhanced EN (EN + glutamine [Gln]) group, standard EN group and control group. Serum parameters including total protein, albumin, proalbumin and transferrin were examined on preoperative day 1, postoperative day 2 and day 12. Levels of immunoglobulin M (IgM), immunoglobulin G (IgG), natural killer (NK) cells, CD4⁺ and CD8⁺ T cells were also compared.

RESULTS

The formulas were tolerated well in all the patients except 5 with mild complications. The EN + Gln and EN groups showed a faster onset of flatus and shorter hospitalization duration than the control group. On postoperative day 12, serum total protein, albumin, proalbumin and transferrin levels of the EN + Gln and EN groups were significantly higher than those of the control group (P < 0.05). CD4⁺ T cells, NK cells, IgM and IgG levels of the EN + Gln group increased prominently, and were significantly higher than those before the operation as well as those in the EN and control groups.

CONCLUSION

Immune-enhanced EN can improve nutritional status and immune function for the patients with AGC after total gastrectomy.

T-staging of gastric cancer of air-filling multidetector-row CT: comparison with hydro-multidetector-row CT

PURPOSE

The purpose of this study was to evaluate the accuracy of T-staging of gastric cancer by air-filling multidetector-row CT (air-MDCT) compared with water-filling MDCT (hydro-MDCT).

MATERIALS AND METHODS

One hundred fifteen patients with histologically diagnosed gastric cancer were included in this study. Fifty-eight patients underwent air-MDCT, and the remaining 57 had hydro-MDCT using a 64-channel scanner. Based on the volumetric data of contrast-enhanced MDCT obtained about 75 s after intravenously injecting 525 mg iodine per kilogram patients weight (525 mgI/kg) nonionic contrast material at the rate of 2 ml/s, oblique coronal and oblique sagittal multi-planar reformatted images perpendicular to the stomach wall, including the tumor, were reconstructed on a workstation. Mural invasion of gastric cancer into the gastric wall, as visualized by CT, was classified according to the TNM classification, and the results of T-staging by MDCT were compared with those by pathologic analysis after surgery.

RESULTS

Correct assessment of T-staging by air-CT was achieved in 48 of 58 patients (83%), and that by hydro-MDCT was 49 of 57 patients (86%). The sensitivity, specificity, and accuracy of the technique in determining the invasion of serosa were 88%, 93%, and 91% for air-CT and 83%, 95%, and 91% for hydro-CT. There were no significant differences between hydro-MDCT and air-MDCT in sensitivity (P=0.73), specificity (P=0.71) and accuracy (P=0.98).

CONCLUSION

Air-MDCT is a very valuable tool in T-staging of gastric cancer as well as hydro-MDCT.

Evaluation of early gastric cancer at multidetector CT with multiplanar reformation and virtual endoscopy

Early gastric cancer (EGC) is defined as a carcinoma in which invasion is limited to the mucosa and submucosa, regardless of lymph node status and distant metastasis. Recent advances in multidetector computed tomography (CT) with multiplanar reformation (MPR) provide a powerful tool for identifying gastric wall invasion and the perigastric extent of gastric cancer. In addition, MPR images confer advantages in the assessment of both intra- and extraluminal processes of the gastric wall and the evaluation of more distant regions, such as the paraaortic lymph nodes and other abdominal organs. Virtual endoscopy performed after air distention of the stomach can aid in the evaluation of gastric endoluminal morphologic features and the extent of EGC. Moreover, virtual endoscopy helps in detecting subtle mucosal changes and differentiating them from submucosal lesions in the same way as conventional endoscopy. Virtual endoscopy can depict abnormal endoluminal lesions within a wider field of view than can conventional endoscopy, and there are no "blind spots" because retrospective image reformation is available, which provides useful information for preoperative mapping. Multidetector CT with MPR and virtual endoscopy is a powerful, noninvasive tool for the early detection and accurate preoperative staging of EGC.

Detection of early gastric cancer using hydro-stomach CT: Blinded vs unblinded analysis

AIM: To evaluate the difference in diagnostic performance of hydro-stomach computed tomography (CT) to detect early gastric cancer (EGC) between blinded and unblinded analysis and to assess independent factors affecting visibility of cancer foci.

METHODS: Two radiologists initially blinded and then unblinded to gastroscopic and surgical-histological findings independently reviewed hydro-stomach CT images of 110 patients with single EGC. They graded the visibility of cancer foci for each of three gastric segments (upper, middle and lower thirds) using a 4-point scale (1: definitely absent, 2: probably absent, 3: probably present, and 4: definitely present). The sensitivity and specificity for detecting an EGC were calculated. Intraobserver and interobserver agreements were analyzed. The visibility of an EGC was evaluated with regard to tumor size, invasion depth, gastric segments, histological type and gross morphology using univariate and multivariate analysis.

RESULTS: The respective sensitivities and specificities [reviewer 1: blinded, 20% (22/110) and 98% (215/220); unblinded, 27% (30/110) and 100% (219/220)/reviewer 2: blinded, 19% (21/110) and 98% (216/220); unblinded, 25% (27/110) and 98% (215/220)] were not significantly different. Although intraobserver agreements were good (weighted κ = 0.677 and 0.666), interobserver agreements were fair (blinded, 0.371) or moderate (unblinded, 0.558). For both univariate and multivariate analyses, the tumor size and invasion depth were statistically significant factors affecting visibility.

CONCLUSION: The diagnostic performance of hydro-stomach CT to detect an EGC was not significantly different between blinded and unblinded analysis. The tumor size and invasion depth were independent factors for visibility.

Three-dimensional MDCT for preoperative local staging of gastric cancer using gas and water distention methods: a retrospective cohort study

OBJECTIVE

The purpose of this article is to compare the T-staging accuracy and lesion detectability of MDCT with gas distention versus water distention according to the surgical and histopathologic findings, for the preoperative evaluation of gastric cancer.

MATERIALS AND METHODS

For a 3-month period, 113 consecutive patients (72 men and 41 women; age range, 23-85 years; mean age, 58 years) with 116 surgically confirmed gastric cancers from a single institution were included in our study. All patients had undergone preoperative MDCT with either effervescent granules taken orally (n = 55) or after having drunk 1,000 mL of tap water (n = 58) to create gastric distention. In addition to transverse images, multiplanar reformation images and 3D surface shaded display images were also obtained with gas distention CT, and multiplanar reformation images were obtained with water distention CT. The CT images were retrospectively reviewed by two abdominal radiologists separately with regard to T staging and lesion detectability. The accuracy values were compared between the two methods using Fisher's exact test.

RESULTS

The T-staging accuracy for gastric cancer did not differ significantly between gas distention and water distention CT scans, according to both radiologists (p > 0.05). Furthermore, the staging accuracy values for T1a cancers on gas distention CT scans for radiologists 1 and 2 were also comparable with those of water distention CT scans (91.1% vs 85% for radiologist 1 and 89.3% vs 85% for radiologist 2; p > 0.05). However, the tumor detection rate was significantly higher on gas distention CT scans using 2D and surface shaded display images for both radiologists (94.6% for radiologist 1 and 91.1% for radiologist 2), compared with the rates for water distention CT scans (78.3% and 73.3%) or gas distention CT scans using only 2D images (75.0% and 67.9%) (p < 0.05).

CONCLUSION

MDCT using the gas distention technique showed performance comparable to that of the water distention technique for the T staging of preoperative gastric cancer with better lesion detectability.

Comparison between blinded and partially blinded detection of gastric cancer with multidetector CT using surgery and endoscopic submucosal dissection as reference standards

The aim of this study is to compare blinded with partially blinded detection of gastric cancer with multidetector (MD) CT by using surgery and endoscopic submucosal dissection (ESD) as reference standards. 44 patients with gastric cancer underwent MDCT with air as an oral contrast agent. Surgery was performed on 37 patients, ESD on six and surgery after ESD on one. To provide comparison cases of blinded evaluation, 38 MDCT examinations were added for cases where no focal gastric lesion was seen on endoscopy. Two radiologists, blinded to the presence, number and location of the tumours, evaluated axial and axial plus multiplanar reformation (MPR) images of 82 MDCT examinations with or without gastric cancer. For partially blinded evaluation, the same radiologists, blinded to the location and number of tumours, evaluated axial and axial plus MPR images of 44 MDCT examinations of gastric cancer. Differences in assessment were resolved by consensus. 45 gastric cancers were found in surgical and ESD specimens. Detection rates of gastric cancer from axial and axial plus MPR images during blinded evaluation and from axial and axial plus MPR images during partially blinded evaluation were 62% (28/45), 64% (29/45), 64% (29/45) and 71% (32/45), respectively. There was no statistical significance for the comparison between blinded and partially blinded detection rates of gastric cancer. The detection rate of gastric cancer with MDCT during blinded evaluation showed no specific difference compared with the detection rate of gastric cancer with MDCT during partially blinded evaluation.

Value of multidetector-row computed tomography in the preoperative T and N staging of gastric carcinoma: a large-scale Chinese study

OBJECTIVES

To investigate the value of multidetector-row computed tomography (MDCT) in the preoperative T and N staging of gastric carcinoma and to further investigate the clinicopathological factors affecting the diagnostic accuracy.

METHODS

Seven hundred ninety gastric carcinoma patients underwent preoperative MDCT examination. The results of MDCT were compared with surgical and pathological findings.

RESULTS

Early gastric carcinoma patients whose primary tumor was detected by MDCT had higher incidence of lymph node metastasis, larger tumor size, and deeper invasion. The overall accuracy of MDCT in determining T stage of gastric carcinoma was 73.80% (T1 45.93%, T2 53.03%, T3 86.49%, and T4 85.79%). The overall accuracy of MDCT in preoperative N staging was 75.22% (N0 76.17%, N1 68.81%, and N2 80.63%). The overall diagnostic sensitivity, specificity, and accuracy of MDCT for determining lymph node metastasis was 86.26%, 76.17%, and 82.09%, respectively. Multivariate analysis showed that the diagnostic sensitivity of MDCT in determining lymph node metastasis related with tumor size, N stage, and number of metastatic lymph nodes.

CONCLUSIONS

The clinical value of MDCT in the preoperative T and N staging of gastric carcinoma is relatively high. MDCT can be the first choice for the preoperative evaluation of patients with gastric carcinoma.