MINISTRY OF EDUCATION MINISTRY OF AND TRAINING DEFENCE SCIENTIFIC RESEARCH INSTITUTE OF CLINICAL MEDICINE 108 ********** NGUYEN VAN SANG STUDY THE VALUE OF MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY IN THE DIAGNOSTIC STAGING OF GASTRIC CANCER Specialisation : Image diagnostics Code : 627220166 THESIS SUMMARY OF DOCTORAL DISSERTATION IN MEDICINE HA NOI - 2019 THESIS IS COMPLETED AT 108 MILITARY CENTRAL HOSPITAL Science instructors: Do Duc Cuong, Associate Professor, M.D, Ph.D Trieu Trieu Duong, Associate Professor, M.D, Ph.D Reviewer 1: Reviewer 2: Reviewer 3: The dissertation will be defended in front of the University level Dissertation Committee at 108 Central Military Hospital at o’clock … month … day … year… This thesis can be searched at: National Library of Vietnam Library of scientific research institute of clinical medicine 08 INTRODUCTION The rate of patients suffering from of gastric cancer keeps increasing That of gastric cancer in Southeast Asia including Vietnam is 15/100.000 Carcinoma is the most common, which accounts for 90% If gastric cancer is diagnosed and treated early, the survival rate of above years can reach 90% However, it is often diagnosed late, so the disease has a high mortality rate Gastroscopy, edoscopic ultrasound (EUS) cannot be used to evaluate TNM stages, which causes difficulties in the treatment process Multidetector-row computed tomography (MDCT) can evaluate stages of TNM In the world, there are many studies that have evaluated values and limitations of the MDCT method To date, there is no final criteria for predicting lymph node (LN) metastasis among researchers with using MDCT In Vietnam, there are many researches on T and N stages, but no metastatic LN studies to divide the gastric cancer stages have been found Hence, we carried out this topic with two objectives: Describe the characteristics of gastric cancer images on multidetector-row computed tomography Study the value of multidetector-row computed tomography in the diagnosis of T and N stages of gastric cancer THE NECESSITY OF RESEARCH Currently, there has been great progress in the diagnosis of gastric cancer thanks to the strong development of modern facilities (Gastroscopy, EUS, MDCT) Abdominal MDCT plays a very important role in helping clinical physicians assess the gastric cancer stages, from which to select appropriate treatments and prognosis In the world, there have been many valuable studies using abdominal MDCT to diagnose gastric cancer In Vietnam, there are also studies on gastric cancer, but there is no adequate study on the value of MDCT in gastric cancer diagnosis, especially the evaluation of metastasis LNs which is an important factor affecting the prognosis as well as helping the surgeon make a surgery plan (open surgery or endoscopic surgery, LN dissection) Therefore, the research is necessary, emerging and has scientific and practical meanings NEW CONTRIBUTION OF THE RESEARCH Dividing stages of gastric cancer according to AJCC obtained the following results: overall accuracy: 46.6%, Sn: 30.8 – 62.5%, Sp: 78.3% - 100%, Acc: 70.5% - 87.5%, PPV: 36.4% - 100%, NPV: 84.4% - 94.8% The following characteristics, which has significant values in the diagnosis of gastric cancer on MDCT, include tumor length, tumor position and microscopic classification (The difference is not statistically significant in dianosing stages by MDCT and histologic) However, the limitations of MDCT are tumor differentiation, invasive tumor, N stage, stages of gastric cancer and number of metastatic LN /harvested LN (The difference is statistically significant dianosing stages by MDCT and histologic) Its low sensitivity of N and AJCC staging presents problems when using it to make therapeutic decisions, which was shown by this research Therefore, improvements in imaging equipment and techniques will be essential in overcoming the drawbacks of this method, and rigorous criteria should be developed to diagnose metastatic LNs THESIS STRUCTURE The thesis includes 130 pages; page introduction, 39 page overview, 19 page objects and methods, 30 page results, 37 page discussions, page conclusions, 01 page recommendation The thesis has 52 tables, 49 illustrations, charts 97 references in which Vietnamese has 11 CHAPTER 1: OVERVIEW 1.1 Outline of gastric caner Among gastric cancers, carcinoma is the most important and also the most common, accounting for 90-95% The rate of pyloric antrum cancer is 50-60%, and the rate of the lesser curvature cancer is 20-30% Early gastric cancer is often flat, smaller than 3cm, discreet and difficult to identify Advanced gastric cancer includes main forms: polypoid, fungating, ulcerated and diffusely infiltative According to Lauren’s classification, microscopic is divided into types: intestinal type and diffuse type Besides, the mixed type includes both intestinal type and diffuse type TNM classification according to AJCC is based on tumor invasion, metastasis LN and distant metastasis Table 1.1: T-staging of gastric cancer, AJCC 7th manual Tumor - T Primary tumor cannot be assessed T0 No evidence of primary tumor Carcinoma in situ: intraepithelial tumor without invasion Tis of the lamina propria Tumor invades the lamina propria, muscularis mucosae, T1 or submucosa T1a Tumor invades the lamina propria or muscularis mucosae T1b Tumor invades the submucosa T2 Tumor invades the muscularis propria T3 Tumor penetrates the subserosal connective tissue T4 Tumor invades the serosa or adjacent structures T4a Tumor invades the serosa T4b Tumor invades adjacent structures TX Table 1.2: N-staging of gastric cancer, AJCC 7th manual Node - N NX N0 N1 N2 N3 Regional lymph node(s) cannot be assessed No regional lymph node metastasis Metastasis in to regional lymph nodes Metastasis in to regional lymph nodes Metastasis in or more regional lymph nodes Table 1.4 Stage and prognostic group of gastric cancer, AJCC 7th manual Stage Stage I A Stage I B Stage II A Stage II B Stage III A Stage III B Stage III C Stage IV Tis T1 T2 T1 T3 T2 T1 T4a T3 T2 T1 T4a T3 T2 T4b T4a T3 T4b T4a Any T N0 N0 N0 N1 N0 N1 N2 N0 N1 N2 N3 N1 N2 N3 N0;N1 N2 N3 N2; N3 N3 Any N M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M0 M1 1.2 Diagnostic methods of gastric cancer 1.2.3.1 Gastric X-ray Double contrast allows us to identify lesions more clearly when there are abnormal changes in the gastric mucularis The advantage of this method is that it is used for patients without gastroscopic indications The disadvantage is that the diagnose is more difficult and it cannot evaluate TNM 1.2.3.2 Gastroscopy - biopsy It is widely applied and causes less catastrophes Some patients with pyloric stenosis or pyloric stenosis-causing tumor will cause many difficulties for gastroscopy and biopsy Gastroscopy does not evaluate TNM 1.2.3.3 Edoscopic ultrasound EUS evaluates T invasion well but does not evaluate distant LNs and distant metastasis 1.2.3.4 Magnetic resonance imaging Compared to those using MDCT, there are several studies of gastric cancer diagnosis using MRI, largely due to the intrinsic limitations of MRI, such as the susceptibility to bulk motion (e.g., respiration, pulsation, and peristalsis), high cost, and lower spatial resolution compared to MDCT or EUS) 1.2.3.5 PET/CT PET/CT cannot evaluate metastasis LNs PET / CT is mainly used for detecting distant metastases 1.3 MDCT in the diagnosis of gastric cancer 1.3.2 Image of gastric cancer on MDCT The image of gastric cancer on MDCT varies according to the anatomy Direct signs can be seen: The gastric wall can be divided into two or three layers (there may be only one layer in advanced gastric cancer such as T3 and T4) If the mucosal layer was unevenly thickened and showed abnormal enhancement on MDCT, a mucosal lesion or gastric cancer would be diagnosed Early gastric cancer with ulceration would be considered when focal interruption of mucosa with adjacent nodularity or thickening was found If only focal interruption of the mucosal layer was found, a benign gastric ulcer would be considered A lesion was determined to be cancer ous when the gastric wall showed focal thickening of at least 5-6 mm or greater or when focal enhancement was seen in the gastric wall.) Although many radiologists classify metastasis LNs as those with short axis diameters of 6-8 mm for perigastric LNs, other criteria are frequently used, including sphericalness and central necrosis, heterogeneous enhancement, more than , marked enhancement (over 80 or 100 HU), and clustering of more than three LNs To date, the accuracy of predicting LNs metastasis has not been satisfactory using any criteria, and there is still no worldwide consensus for diagnosing metastatic LNs using MDCT N-staging of gastric cancer is one of the inherent limitations of MDCT) The LNs are only identified on histologic by microscopy to identify metastatic-negative LNs or metastasis-positive LNs (metastatic-negative LNs are LNs without metastatic cells in LNs, metastatic-positive LNs are LNs with metastatic cells in the LNs) CHAPTER 2: OBJECT AND METHODOLOGY 2.1 Objects of the research 2.1.1 Location and time of research The research was conducted at Military Central Hospital 108 from September 2015 to October 2016 2.1.2 Objects of the research Patients was diagnosed with gastric cancer, taken with MDCT 16 were identified as epithelial cancer by histology and were under gastrectomy surgery at 108 Military Central Hospital 2.1.2.1 Criteria to select patients Diagnosis identifies gastric cancer on gastroscopy and histology The patients received radical surgery at 108 Military Central Hospital The patients had radical surgery for the first time, not using chemotherapy, regardless of age and gender 2.1.2.2 Exclusion criteria MDCT patients who were not well performed according to preoperative techniques at 108 Military Central Hospital 2.2 Methods of research 2.2.1 Research design This is a cross-sectional descriptive and prospective research in which there is a comparison among MDCT, surgery and histopathology 2.2.2 Sample size With the accuracy of T stage according to author Kim JW and et al which is 77.2%, error m = 10% Apply for cross-sectional descriptive research n≥ 68 patients We have n = 88 patients 2.2.3 Research tools MDCT machine with 16 rows of BRIVO CT 385 detectors GE US is located at the Diagnostic imaging Department, in 108 Military Central Hospital Medical record forms are all the same 2.2.4 Analyzing and processing data The research data is encoded, imported, processed and analyzed on computers using SPSS 22.0 medical statistical software Using chi square test (χ2) for ratios, Test - T - Student (two groups), anova (3 groups or more) for quantitative variables The difference is statistically significant with p