Gastric Cancer Imaging: Computed Tomographic Pneumogastrography

Objective: to reveal technical nuances for obtaining high-quality images using a computed tomography protocol with pneumogastrography and virtual gastroscopy, which contribute to the detection and assessment of the morphological type of gastric cancer and to the determination of its localization and invasion depth.Material and methods. The investigation enrolled 250 patients with both early (24.8%) and locally advanced (75.2%) gastric cancer treated in Petrov National Medical Research Center for Oncology from 2015 to 2018. Preoperative chemotherapy was performed in 142 (56.8%) patients and was not done in 108 (43.2%). All the patients underwent preoperative computed tomography with pneumogastrography and virtual gastroscopy. All the patients were radically operated on through subtotal or total gastric resection.Results. Computed tomography with pneumogastrography and virtual gastroscopy was used to detect gastric cancer in 98.4% of patients; the cases with early T1a and T1b invasion depth cancers were 23.2%. The tumor could not be significantly differentiated in 4 (1.6%) patients. This group consisted of: 3 (1.2%) and 1 (0.4%) patients with pT1a and pT1b invasion depth tumors, respectively. All non-visualized tumors had a superficial morphological type of growth (Type 0–II (3 cases with 0–IIa and 1 case with 0–IIb); their sizes were less than 2 cm. Three tumors were localized in the antral portion of the stomach; one was in its cardiac portion.Conclusion. Computed tomography with pneumogastrography and virtual gastroscopy is an effective technique to detect gastric cancer, including its early types of category T1, which makes it possible to assess its localization, morphological type, and invasion depth.

Diagnosis and t-staging of gastric cancer: comparison of standard computed tomography and computed-tomographic pneumogastrography

The advantages of computed tomographic pneumogastrography with the possibility of three-dimensional visualization and virtual gastroscopy in diagnosing gastric cancer are considered. The study included 479 patients with histologically diagnosed gastric cancer who were treated at the National Medical Research Center of Oncology named after N.N. Petrov from 2011 to 2018. 232 patients received preoperative chemotherapy. All patients underwent surgery: 70 in the volume of endoscopic dissection, 40 proximal subtotal resection, 166 distal subtotal resection, 203 gastrectomy. All patients at the preoperative stage underwent staging computed tomography on a 64-slice X-ray computed tomograph: 208 patients underwent computed tomography according to the standard protocol without targeted preparation of the stomach for the study, 271 patients with targeted preparation of the stomach for the study according to the computed tomographic pneumogastrography protocol. The sensitivity of the computed tomography in assessing the T-stage was assessed by comparison with pathomorphological data. Of the 208 patients who underwent computed tomography according to the standard protocol, a gastric cancer was detected in 111 (53.4%), out of 271 patients who underwent computed tomography pneumogastrography, a gastric cancer was detected in 267 (98.52%), which is a statistically significant difference in comparing computed tomography methods (Pearson, 144.223, df = 1; p 0.001). There are statistically significant differences when comparing computed tomography according to the standard protocol and computed tomographic pneumogastrography in detecting gastric cancer for all tumor categories: T/yT1 8.2 and 94.4% (Pearson, 99.205, df = 1; p 0.001), T/yT2 47.8 and 100% (Pearson, 24.681, df = 1; p 0.001), T/yT3 72.3 and 100% (Pearson, 33.114, df = 1; p 0.001), T/yT4 90.0 and 100% (Pearson, 4.789, df = 1; p = 0.029) respectively. There are also statistically significant differences when comparing the sensitivity of computed tomography according to the standard protocol and computed tomographic pneumogastrography in determining tumor invasion for all tumor categories: T/yT1 0 and 69.4% (Pearson, 67.880, df = 1; p 0.001), T/yT2 26.1 and 71.1% (Pearson, 11.666, df = 1; p 0.001), T/yT3 32.9 and 84.6% (Pearson, 54.900, df = 1; p 0.001), T/yT4 73.3 and 95.7% (Pearson, 7.916, df = 1; p = 0.005) respectively. In general, the sensitivity of the computed tomography according to the standard protocol for determining the T-stage of gastric cancer was 28.4%, computed tomographic pneumogastrography 77.1% (Pearson, 113.505, df = 1; p 0.001). Computed tomographic pneumogastrography with the possibility of three-dimensional visualization and virtual gastroscopy significantly increases the indicators of the effectiveness of diagnosing gastric cancer both early forms (category T1) and with deeper invasion (categories T2T4), demonstrates high sensitivity in determining T/yT-stages.

Demonstration of the Capabilities of Transabdominal Ultrasonography in Assessment of Structures and Functional Disorders of Locally Advanced Gastric Cancer of Diverse Localization

Introduction: Ultrasound study of locally advanced gastric cancer that has spread to adjoining tissue and lymph nodes. This tumor can be associated with T2 to T4 stages of cancer. A “Locally advanced gastric cancer” is a tumor, which may be categorized as ‘resectable’ cancer when compared with M1 advanced cancer. Objective: The aim of this study was to evaluate the Capabilities of transabdominal ultrasonography in assessment of structures and functional disorders of the locally advanced gastric cancer of diverse localization Materials and Methods: A total of61 patients with locally advanced gastric cancer were analyzed of which 36 (59,0%) were males (mean age 62.7 years) and 25 (41,0%) were females (mean age 59.3 years). All patients were managed surgically and underwent preoperative X-ray, virtual gastroscopy techniques, multidetector computed tomography and transabdominal ultrasonography (USG). Histopathology results found, in 58 (95,1%) cases adenocarcinoma, in 3 (4,9%) – ring-cell carcinoma (cricoidal) gastric cancer was established. Stage T2 was diagnosed in 16 (26.2%) cases, T3 - in 41 (67.2%) cases, T4 - in 4 (6.6%) cases. The stomach tumor in 29 (47.5%) cases was localized mainly in the antrum, 27 (44.3%) – in the body, 5 (8.2%) in the cardia and fundus (Table 1). In 24 (39,3%) cases, pyloric stenos was diagnosed - of which in 6 (9,8%) it was compensated, in 18 (29,5%) - sub compensated. All patients underwent preoperative X-ray, virtual gastroscopy techniques, multidetector computed tomography and transabdominal ultrasonography (USG). Normal ultrasound features were observed in 35 patients without gastric pathology. Ultrasonography was carried out with the convex and micro convex transducers in the frequency range of 2-5 MHz and 4-7 MHz respectively in B and color Doppler modes. Results: The polypoid type of gastric cancer was detected in 3 (4,9±2,8%) cases, the ulcerative type – in 18 (29,5±5,8%), the infiltrative ulcerative type – in 27 (44,3±6,4%) and the diffuse infiltrative type – in 13 (21,3%±5,2%) cases respectively. In 24 (39,3%) cases, pyloric stenos was diagnosed - of which in 6 (9,8%) it was compensated, in 18 (29,5%) – sub compensated. The layers of the gastric wall were not differentiated in all patients with sub compensated pyloric stenos. The gastric wall thickness of the affected area was 10,2±2,9mm in the case compensated pyloric stenosis, the length was 27,1±6,2mm, the diameter of the pylorus was 8,3±0,8mm. Among patients with sub compensated pyloric stenos, the thickness of the gastric wall was 19,8±4,1mm, the length was 43,6±4,5mm, the pyloric diameter was 4,3±1,1mm. Among the 61 patients studied, pathological vascularization was detected in 42 (68.8%) cases. It was observed that, all 4 (6.5%) patients with gastric cancer were stage T4 and 38 (62.3%) were stage T3. Vascularization was weak in 13 cases, in 24 cases - moderate, and in 5 cases - enhanced. Metastases to the regional lymph nodes were diagnosed in 52 cases. Ultrasonographically, they were detected only in 37 (71.2%) cases. Conclusions: In the diagnosis of locally advanced gastric cancer, ultrasonography demonstrates good capabilities for determining the extent and depth of the affected area. Color doppler mode allows the study of vascularisation of a locally thickened area, as well as nearby enlarged lymph nodes, which is very important to ascertain the degree of malignancy of the hyperplastic process. ltrasonography can independently determine the degree of pyloric stenosis in patients with distal gastric cancer.

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.