Study the value of multidetector row computed tomography in the diagnostic staging of gastric cancer tt tiếng anh

SCIENTIFIC RESEARCH INSTITUTE OF CLINICAL MEDICINE 108 ********** NGUYEN VAN SANG STUDY THE VALUE OF MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY IN THE DIAGNOSTIC STAGING OF GASTRIC CANCE

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

THESIS SUMMARY OF DOCTORAL DISSERTATION IN MEDICINE

HA NOI - 2019

Science instructors:

1 Do Duc Cuong, Associate Professor, M.D, Ph.D

2 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 5 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:

1 Describe the characteristics of gastric cancer images on multidetector-row computed tomography

2 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; 2 page introduction, 39 page overview,

19 page objects and methods, 30 page results, 37 page discussions, 2 page conclusions, 01 page recommendation The thesis has 52 tables, 49 illustrations, 5 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

4 main forms: polypoid, fungating, ulcerated and diffusely infiltative According to Lauren’s classification, microscopic is divided into 2 types: intestinal type and diffuse type Besides, the mixed type includes both intestinal type and diffuse type TNM classification according to AJCC 7 is based on tumor invasion, metastasis LN and distant metastasis

Table 1.1: T-staging of gastric cancer, AJCC 7 th manual

Tumor - T

TX Primary tumor cannot be assessed

T0 No evidence of primary tumor

Tis Carcinoma in situ: intraepithelial tumor without invasion

of the lamina propria

T1 Tumor invades the lamina propria, muscularis mucosae,

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

Table 1.2: N-staging of gastric cancer, AJCC 7th manual

Node - N

NX Regional lymph node(s) cannot be assessed

N0 No regional lymph node metastasis

N1 Metastasis in 1 to 2 regional lymph nodes

N2 Metastasis in 3 to 6 regional lymph nodes

N3 Metastasis in 7 or more regional lymph nodes

Table 1.4 Stage and prognostic group of gastric cancer, AJCC

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<0.05 Confidence interval

of Odds Ratio (OR)

Continuous and quantitative variables are presented as average values with standard deviation X± SD

The results of the collection and analysis are presented in the form

of frequency, percentage, average value, used to express the results in the tables and charts

Indicators of Sn, Sp, Acc, PPV and NPV are determined by table setting method

Calculate kappa coefficients: To find relevance

Calculate sugar ROC: To determine the optimal cutting point

3.1.1 Age, gender

Table 3.1:Distribution of patients by age and gender

Age group Male (n,%) Female (n,%) Total (n,%)

60.9 ± 14.4 (33 - 84)

63.2 ± 11.5 (33 - 86)

p (T-test) = 0.252

Comment: The average age in the research was 63.2 ± 11.5 (33 - 86)

years There is no difference in the average age of male and female,

with p> 0.05

3.1.3 Microscopic classification

Chart 3.2: Lauren’s classification Comment: Mixed type is the most common (36.4%) Type of intestinal tye is the least common (30.7%)

3.2 Imaging characteristics of gastric cancer by MDCT

is 34.5 ± 16.9 (4 - 91) mm

Table 3.5: Thickness of the tumor

3.2.1.3 Attenuation value and tumor differentiation

Table 3.6: Attenuation value and tumor differentiation

Portal venous phase 131.9 ± 20.7 (90-180)

Comment: The majority of the tumors is undifferentiated (80.7%)

The average attenuation value of the tumors in portal venous phase is 131.9 ± 20.7 (90 - 180)HU

3.2.1.4 The extent of the tumor invasion

The research group I has a general Acc of 73.9% The research group II has a general Acc of 72.7% Kappa coefficient is 0.911 with

p <0.05 Relevance between the two independent research teams is very high, so the results of research group I should be selected

3.2.2 Lymph characteristics

The research group I diagnosed 460 LNs The II one diagnosed 485 LNs The overall Kappa coefficient was 0.926 Relevance between the two independent research teams is very high

3.2.2.2 Lymph nodes size

Table3.13: Relation of metastasis level, size and the near-far

51 (58.0)

30 (78.9)

155 (36.6) 0.000

(χ 2 )

(79.1)

75 (68.2)

37 (42.0)

8 (21.1)

268 (63.4)

10 (27.0) 0.001

(χ 2 )

(100)

5 (100)

8 (80.0)

4 (33.3)

27 (73.0)

Total

(19.8)

35 (30.4)

53 (54.1)

38 (76.0)

45 (45.9)

12 (24.0)

295 (64.1)

Comment: In near lymph nodes, there is statistically significant

difference of percentage of metastasis LNs among size groups (p<0.05) In far LNs, there is statistically significant difference of

percentage of metastasis LNs among size groups (p<0.05)

Table3.14: Relation between medium size and characteristics of

group and LN shape

Characteristics Metastasis Average p (T test)

Comment: The average size of near negative and

metastasis-positve LNs as well as far metastasis-negative and metastasis-positive LNs has difference which is statistically significant (p<0.05) The average size

of oval metastasis-negative and metastasis-positive LNs as well as spherical metastasis-negative and metastasis-positive LNs has difference which is statistically significant (p<0.05)

3.2.2.4 Lymph node shape

Table 3.15: Relevant levels of metastatic and lymph node shape

Shape Metastasis LNs

Spherical (n,%)

Oval (n,%)

Total (n,%)

more than oval lynph nodes

3.2.2.5 The properties of enhancement contrast of lymph nodes

Table 3.18 Relationship between LN size and contrast

Comment: LNs of metastatic contrast metastases have bigger size

than non-absorbent LNs benign contrast The difference is statistically significant with p <0.05

3.2.2.6 Limitation of negative-positive metastasis and metastasis LN size of LNs on MDCT

Figure 3.4 The ROC curve is related to the size of negative-positive

metastasis LNs on MDCT

Comment: The area under the curve is above 0.6 With high

sensitivity and specificity (71.5% and 70.5%), metastatic lymphadenectomy point has the size of > 7.5 mm Thus, our research using 8mm diameter is suitable with other authors

3.3 Value of MDCT in the diagnosis staging of gastric cancer 3.3.1 Value of MDCT in the diagnosis of T stage

3.3.1.2 Comparison in the diagnosis of T stage with MDCT versus

T stage with histologic evaluation