Từ kết quả nghiên cứu 66 BN (51 BN điều trị tại Bệnh viện Quân y 103 và 15 BN điều trị tại Bệnh viện K-cơ sở Tân Triều), chúng tôi thấy có những đóng góp mới như sau: Giá trị chụp cắt lớp vi tính ổ bụng trong chẩn đoán ung thư 1/3 dưới dạ dày được điều trị phẫu thuật triệt căn Chụp cắt lớp vi tính là phương pháp tốt để chẩn đoán ung thư 1/3 dưới dạ dày, giúp đánh giá chính xác tình trạng xâm lấn u, mức độ di căn hạch, di căn xa và giai đoạn bệnh. Tỷ lệ chẩn đoán đúng mức độ xâm lấn của chụp cắt lớp vi tính là 75,76%. Độ nhạy, độ đặc hiệu, giá trị tiên đoán dương, giá trị tiên đoán âm và độ chính xác của mức độ xâm lấn T1 là 55,56%; 96,49%; 71,43%; 93,22%; 90,91%. T2: 92,31%; 90,57%; 70,59%; 97,96%; 90,91%. T3: 86,36%; 84,09%; 73,08%; 92,50%; 84,85%. T4: 63,64%; 95,45%; 87,50%; 84,00%; 84,85%. Độ nhạy trong phát hiện di căn tạng của phương pháp chụp cắt lớp vi tính ổ bụng: 100%; độ đặc hiệu: 100%; giá trị tiên đoán dương tính: 100%; giá trị tiên đoán âm tính: 100%. Tỷ lệ chẩn đoán chính xác của chụp cắt lớp vi tính ổ bụng trong chẩn đoán di căn hạch: 62,12%. Độ nhạy, độ đặc hiệu, giá trị tiên đoán dương, giá trị tiên đoán âm và độ chính xác trong chẩn đoán di căn hạch là 78,26%; 65,00%; 83,72%; 56,52%; 74,24%. N1: 75,00%; 87,04%; 56,25%; 94,00%; 84,85%. N2: 68,00%; 85,37%; 73,91%; 81,40%; 78,79%. N3: 22,22%; 96,49%; 50,00%; 88,71%; 86,36%. Kết quả phẫu thuật triệt căn điều trị ung thư 1/3 dưới dạ dày Kết quả phẫu thuật điều trị ung thư dạ dày trong nghiên cứu là khả quan với tỷ lệ biến chứng thấp và thời gian sống thêm đáng khích lệ. Biến chứng sớm sau phẫu thuật ung thư dạ dày 1/3 dưới, tắc ruột có tỷ lệ 1,5%. Thời gian sống thêm toàn bộ trung bình là 73,16 ± 6,35 tháng. Tỷ lệ sống thêm toàn bộ theo Kaplan-Meier sau 1 năm là 87,9%, 2 năm là 66,4%, 3 năm là 54,0%, 4 năm là 54,0%, 5 năm là 54,0%. Tỷ lệ sống thêm 5 năm ở các giai đoạn tương ứng như sau: Ia, Ib, IIa, IIb, IIIa, IIIb, IIIc lần lượt là 77,8%; 72,9%; 37,6%; 70,0%; 33,3%; 36,4%. Thời gian sống thêm chung theo giai đoạn Ib, IIa, IIb, IIIa, IIIb, IIIC, IV là 70,46 ± 6,55 tháng. Tỷ lệ sống thêm 5 năm theo chặng hạch di căn N0 (64,5%), N1 (55,6%), N2(47,4%), N3a (50,0%). Thời gian sống thêm chung theo chặng hạch di căn N0, N1, N2, N3a, N3b là 73,16 ± 6,35. Cán bộ hướng dẫn 1 PGS. TS. Nguyễn Văn Xuyên Cán bộ hướng dẫn 2 PGS. TS. Lê Thanh Sơn Nghiên cứu sinh Heng Lihong THE NEW MAIN SCIENTIFIC CONTRIBUTIONS OF THE THESIS Name of thesis: “Research on the value of computed tomography and results of surgical treament in 1/3 lower gastric cancer” Specialized in: Surgery Code: 9 72 01 04 Full name of researcher: HENG LIHONG Full name of scientific instructors: 1. Assoc. Prof., PhD. Nguyen Van Xuyen 2. Assoc. Prof., PhD. Le Thanh Son Educational foundation: Vietnam Military Medical University The new scientific contributions of the thesis: From the study results, 66 gastric cancer patients diagnosed as the lower third gastric cancer, preoperatively computed tomography, operated at Military Hospital 103 and K Hospital (Tan Trieu campus), we found new contributions as follows: Value of abdominal computed tomography in the diagnosis of the 1/3 lower gastric cancer treated with radical surgery Computed tomography is a good method to diagnose cancer of the 1/3 lower of the stomach, helping to accurately assess tumor invasion, degree of lymph node metastasis, distant metastasis and stage of disease. The rate of correct diagnosis of invasiveness by computed tomography is 75.76%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of T1 invasion were 55.56%; 96.49%; 71.43%; 93.22%; 90.91%. T2: 92.31%; 90.57%; 70.59%; 97.96%; 90.91%. T3: 86.36%; 84.09%; 73.08%; 92.50%; 84.85%. T4: 63.64%; 95.45%; 87.50%; 84.00%; 84.85%. Sensitivity in detecting visceral metastasis of abdominal CT: 100%; specificity: 100%; positive predictive value: 100%; negative predictive value: 100%. Accurate diagnosis rate of abdominal computed tomography in the diagnosis of lymph node metastasis: 62.12%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy in the diagnosis of lymph node metastasis are 78.26%; 65.00%; 83.72%; 56.52%; 74.24%. N1: 75.00%; 87.04%; 56.25%; 94.00%; 84.85%. N2: 68.00%; 85.37%; 73.91%; 81.40%; 78.79%. N3: 22.22%; 96.49%; 50.00%; 88.71%; 86.36%. Results of radical surgery in the treatment of the 1/3 lower gastric cancer The outcome of gastric cancer surgery in the study was positive with low complication rate and encouraging survival time. Early complications after surgery for stomach cancer in the lower third, intestinal obstruction has a rate of 1.5%. The mean overall survival time was 73.16 ± 6.35 months. Overall survival rate according to Kaplan-Meier after 1 year was 87.9%, 2 years was 66.4%, 3 years was 54.0%, 4 years was 54.0%, 5 years was 54.0% . The 5-year survival rate at the respective stages is as follows: Ia, Ib, IIa, IIb, IIIa, IIIb, IIIc respectively 77.8%; 72.9%; 37.6%; 70.0%; 33.3%; 36.4%. The overall survival time according to stages Ib, IIa, IIb, IIIa, IIIb, IIIC, IV was 70.46 ± 6.55 months. The 5-year survival rate according to lymph node metastasis stage N0 (64.5%), N1 (55.6%), N2 (47.4%), N3a (50.0%). Overall survival time according to lymph node metastasis N0, N1, N2, N3a, N3b was 73.16 ± 6.35. The first supervisor
Trang 11 Necessary
Gastric cancer (GC) is the most common malignancy ingastrointestinal cancers According to the announcement of theInternational Organization for Research on Cancer, in 2018, theworld had 1,033,701 new cases and 782,685 deaths from gastriccancer, accounting for 5.7% of all cancers and 8.2% of the totalmortality, ranking 5th in the world among common cancers and 2nd
in mortality after lung cancer
Vietnam belongs to an area of medium-high risk of gastriccancer, with a new incidence of 21.8 for men and 10.0 for women per100,000 population
Computed tomography (CT), a non-invasive method ofdiagnosing gastric cancer, allows to perform thin sections, reconstructimages in the vertical and horizontal directions Based on that, CT scannot only identifies the tumor, tumor location but also assesses theextent of invasion, invasive lymph nodes, metastasis of the tumor tointra-abdominal viscera, or distant metastasis to the lungs, bones, andother distant organs, play an important role in the diagnosis of TNMstages and help in better treatment options Currently, the CT scanningsystem is quite popular in many hospitals The application ofpreoperative CT scanning technique for gastric cancer patients isrelatively convenient There are not many studies on CT in diagnosis
and follow-up of gastric cancer, so we carried out a study on the topic: "
Research on the value of computed tomography and results of surgical treament in 1/3 lower gastric cancer”.
2 Objectives
- Imaging characteristics and value of computed tomography inpatients with the lower third of the gastric cancer treated with radicalsurgery
- Evaluation of the results of radical surgery in the treatment ofthe lower third gastric cancer
3 Valudation of the project
The results obtained through the research contribute to thespecialty on the characteristics of computed tomography,histopathology in the diagnosis of the lower third of the gastric
Trang 2cancer and the results after radical surgery to treat the lower third thegatric cancer.
The topic has scientific significance, practical value, contributing
to improving the quality of diagnosis and treatment, saving patients'lives, improving survival time in patients with the lower third of thegatric cancer
4 Structure of the project
The thesis has 118 pages, including the following parts:Introduction (2 pages), Chapter 1 (Review of literature 35 pages),Chapter 2 (Subjects and methods) 23 pages; Chapter 3 (Results) 28pages; Chapter 4 (Discussion) 27 pages; Conclusion 2 pages;Recommendation 1 page
The thesis has 49 tables, 9 charts, 27 figures and 109 references(20 Vietnamese documents, 89 English documents)
CHAPTER 1 REVIEW OF LITERATURE 1.1 Epidemiological features of gastric cancer
1.2 Pathology and classification of gastric cancer
1.2.1 Pathological features of gastric cancer
1.2.2.1 Tumor location characteristics: Gastric cancer can be found
in any location, but it is most common in the antrum-pyloric regionwith a rate of 70-80%; next, the lesser curvature region with the rate
of 10-15%; in the cardiac, bulge region is about 3-5%; Greatercurvature is rare
1.2.2.2 Macroscopic characteristics: Bormann classification
includes nodules, ulcers, invasive ulcer, and infiltrate
1.2.2.3 Microscopic characteristics: classified according to World
Health Organization and JGCR 3rd
1.2.2 Hình thức xâm lấn, di căn của ung thư dạ dày: Invasive and
metastatic form of gastric cancer: local invasion, lymphaticmetastasis, peritoneal cavity metastasis, hematogenous metastasis
1.2.3 Gastric cancer classification: gastric cancer classification
according to the Japanese Gastric Cancer Association (2011)
1.3 Clinical and sublinical features of lower third gastric cancer
Trang 3Gastric cancer often has no obvious clinical symptoms, specific symptoms can be epigastric pain, flatulence, dyspepsia,fatigue, anorexia, weight loss Anemia is also a symptom.commonly found in UTIs.
non-The typical X-ray images of gastric cancer: lacunae, amputationusually corresponds to nodule, lenticular shapes correspond to ulcers,small rigid tubular stomach, loss of peristalsis corresponds toinfiltrates
Endoscopy is the earliest and most accurate diagnostic method
available today The more biopsies, the greater the accuracy.Endoscopy is a method of early diagnosis of gastric cancer,especially when combined with Indigocalmin staining to indicate thebiopsy area
1.4 Computed tomography to diagnose gastric cancer
1.4.1 A brief history of the study of computed tomography in the diagnosis of gastric cancer
1.4.2 Anantomy of gastric computed tomography
1.4.3 Valuation and limitations of computed tomography in the diagnosis of gastric cancer
1.4.3.1 Image of gastric cancer on computed tomography: Focal
thickening of the gastric wall with mucosal abnormalities, may form
a protrusion into the lumen of the stomach, with a multilobar margin,jagged, may have or no ulcers; may or may not be symmetrical, afterinjection of strongly enhanced or non-enhanced contrast agent.Normal gastric wall thickness is less than 5mm, gastric wall incancerous lesions is defined as ≥1cm thickness Wall thickening withloss of normal mucosal folds Changes in gastric wall thicknessaccompanied by strong contrast enhancement are more pronouncedthan in the rest
1.4.3.2 Detecting tumor:
1.4.3.3 Tumor location: The most common gastric cancer is in the
antrum and pyloric areas In recent years, cardiac gastric cancer tends
to increase
1.4.3.4 Macroscopic assessment of gastric cancer: early gastric
cancer, nodular, non-invasive ulcerative, invasive ulcerative,infiltrative and unclassified
1.4.3.5 Assessment of tumor invasion: T1, T2, T3, T4 invasion.
Trang 41.4.3.6 Evaluation of lymph node metastasis: Evaluation of lymph
node metastasis on CT remains a big challenge even with thegeneration of multi-detector arrays The lymph node is consideredpathological when the short axial diameter of the lymph node is morethan 6 mm for perigastric lymph nodes and more than 8 mm for othersites N1, N2, N3 lymph node metastasis
1.4.3.7 Evaluation of distant metastases: Gastric cancer often
metastasizes to the liver, lymph nodes, peritoneum, ovaries, etc.Distant metastasis is a poor prognostic factor
1.5 Stomach cancer surgical treatment
1.5.1 Radical treatment
Surgery is the mainstay of treatment for GC In the early stage, thecancer is still localized, surgery is the method of choice for radicaltreatment At a later stage, surgery is considered a basic methodcombined with adjuvant methods such as postoperative chemotherapy,pre- and postoperative radiation therapy, and biological treatment
1.5.2 Temporary treatment of the lower third gastric cancer
1.6 Results of treatment for gastric cancer
1.6.1 Early results of surgery
The early surgical outcomes include intraoperative accidentesand deaths, complications, and postoperative mortality Postoperativemortality was defined as patients who were critically ill, dying, ordied within the first 30 days after surgery Postoperativecomplications may be encountered such as: peritonitis, oesophagealfistula, duodenal apex fistula, postoperative bleeding, oropharyngealbleeding…
1.6.2 Late results after surgery: Cancer in general and gastric
cancer in particular often recur in the first 2 years after treatment,especially in the first 5 years Surgery for radical treatment of gastriccancer with the expectation of cure of gastric cancer In the US andWestern countries, the 5-year survival rate in patients undergoingradical surgery is about 25-30%, the 5-year overall survival rate isabout 4-10% In Japan, the 5-year overall survival rate is about 57%,the 5-year survival rate after gastrectomy is about 61%, and thesurgical mortality rate is only about 1%
CHAPTER 2
Trang 5SUBJECTS AND METHODS 2.1 Subjects
Including 66 gastric cancer patients diagnosed as the lower thirdgastric cancer, preoperatively computed tomography, operated atMilitary Hospital 103 and K Hospital (Tan Trieu campus) from 2009
to 2017
2.1.1 Criteria of selection
- Patients with histopathological diagnosis ofadenocarcinoma of the lower third of the stomach (defined ascarcinoma according to WHO regulations and the tumor location inthe lower third according to JGCA 3rd)
- Get a computerized tomography (CT) film of the abdomenwith contrast injection
- Have not had any other type of cancer
- The patient was treated with radical surgery to treat gastriccancer The radical treatment of the lower third gastric cancer isperformed according to the following principles:
+ Gastric bypass: in the lower part of the duodenum, 2 - 3 cmfrom the pylorus At the top, cut at least 6cm from the lesion
+ Remove all the great omentum, the small omentumtogether with the superior area of the transverse mesentery
+ Remove the metastatic lymph node system: remove gastriclymph nodes to level D2
+ Radical resection of invasive or metastatic organs: Invadedorgans such as colon, tail of pancreas, liver or metastases, such asovaries, need to be removed along with the tumor
2.1.2 Exclusion criteria
- The patient did not receive surgical treatment
- Patients with incorrect technique of CT scan
- Patient has cancer in other organs
- The medical record is not full of research information
2.2 Methods
- Retrospective, prospective, descriptive cross-sectional study,longitudinal follow-up to evaluate postoperative outcomes
2.2.1 Research indexes
2.2.1.1 Research criteria and general characteristics of patients
- Age (year), gender (male/female)
- Time of illness
Trang 6- Functional symptoms, physical symptoms
2.2.1.2 Research indicators on computed tomography with gastric cancer
- Tumor diagnostic signs:
- Tumor limit:
- Tumor position:
- Tumor size:
- Tumor thickness:
- Tumor shape: nodules, ulcerative, invasive and infiltrative
- Density, tumor enhancement properties:
- Invasive nature: T1, T2, T3, T4 level
- Research criteria on lymph node metastasis: number of lymphnodes, lymph node location, degree of lymph node metastasis N1,N2, N3
- Research criteria on distant metastasis on CT: M0, M1
- Research indicators on diagnosis of disease stage on CT: Based
on CT results of T, N, and M, determine the stage of lower thirdgastric cancer on CT according to JGCA3rd
2.2.1.3 Research criteria for radical treatment of the lower third gastric cancer
- Surgical methods; Method of closing the duodenal apex;Methods of re-establishing gastrointestinal circulation; Surgery time:
- Early post-operative results: time after surgery, length ofhospital stay, complications, postoperative complications, mortalityrate due to surgery
- Late results after surgery: postoperative complications,recurrence rate, postoperative metastasis, postoperative survival time
2.2.1.3 Research criteria on pathology
Trang 7- The data collected in this study is honest, the researchprocess does not affect the medical examination and treatmentactivities at the relevant clinical departments.
- Patient information is kept confidential
- Medical records during the research process are stored andpreserved carefully, without causing loss
CHAPTER 3 RESULTS
There were a total of 66 patients (51 patients treated at MilitaryMedical Hospital 103 and 15 patients treated at K Hospital - TanTrieu facility) who met the selection criteria and were included in thestudy We get the following results:
3.1 Some characteristics of the lower third gastric cancer
3.1.1 Epidemiological features
Table 3 1 Age and sex characteristics
54.33 ± 14.21(36 – 81)
57.76 ± 11.74(31 – 81)Comment: The average age of the study group was 57.76 ±11.74 (years), in which the oldest person was 81, the youngest was
31 The rate of gastric cancer in men was 72.73% higher than female
is 27.27% The age group 51-60 is the age group with the highest rate
of gastric cancer with 39.39%, the rate of gastric cancer is low in theage group ≤ 40 (9.09%)
3.1.2 Clinical and paraclinical features
Table 3 2 Clinical features
Trang 8Comment: The symptoms encountered with the highest rate were:abdominal pain (75.76%), followed by fatigue, weight loss (48.48%),anorexia, bloating (42.42%), hematemesis symptoms (3.03%),pyloric stenosis are rare.
3.2 Value of computed tomography image of the lower third gastric cancer
3.2.1 Tumor characteristics on computed tomography
Table 3.3 Tumor location on CT Tumor location on CT Number (n) Rate (%)
Table 3.4 Invasion, metastasis of tumor on computed
Trang 9Table 3.5 Stage of gastric cancer on computed tomography
3.2.2 Value of computed tomography in the diagnosis of gastric cancer of the lower third
Table 3.6 Comparison of invasiveness between computed tomography
Trang 10T1a T1b T4a T4b
T1 1(50.00) 4(57.14) 1(7.69) 1(4.55) 0(0.00) 0(0.00) 7(10.61) T2 1(50.00) 0(0.00) 12(92.31) 1(4.55) 2(13.33) 1(14.29) 17(25.76)T3 0(0.00) 2(28.57) 0(0.00) 19(86.36) 2(13.33) 3(42.86) 26(39.39)T4a 0(0.00) 1(14.29) 0(0.00) 1(4.55) 11(73.33) 3(42.86) 16(24.24)
Total 2(3.03) 7(10.61) 13(19.70) 22(33.33) 15(22.73) 7(10.61) 66(100)
Comment: The rate of correct diagnosis of invasiveness of CT scan withpathology: (5+12+19+14)/66 = 75.76% Sensitivity corresponding to thedegree of invasion, respectively: T1: 5/9 = 55.56%; T2: 12/13 = 92.31%;T3: 19/22 = 86.36%; T4: 14/22 = 63.64% The specificity corresponds
to the levels of invasion, respectively: T1: 55/57 = 96.49%; T2: 48/53 =90.57%; T3: 37/44 = 84.09%; T4: 42/44 = 95.45% The positivepredictive value corresponds to the levels of invasion, respectively: T1:5/7 = 71.43%; T2: 12/17 = 70.59%; T3: 19/26 = 73.08%; T4: 14/16 =87.50% The negative predictive value corresponds to the levels ofinvasion, respectively: T1: 55/59 = 93.22%; T2: 48/49 = 97.96%; T3:37/40 = 92.50%; T4: 42/50 = 84.00% The accuracy in diagnosiscorresponds to the levels of invasion, respectively: T1: 60/66 = 90.91%;T2: 60/66 = 90.91%; T3: 56/66 = 84.85%; T4: 56/66 = 84.85%
Table 3.7 Comparison of visceral metastases between computed
tomography and pathology
Comment: There were 2 patients with visceral metastases identified
on preoperative abdominal CT Through the above table, we foundthat the sensitivity in detecting visceral metastases of the abdominal
CT scan method: 2/2 = 100%; specificity: 64/64 = 100%; positivepredictive value: 2/2 = 100%; negative predictive value: 64/64 =100% Accuracy: (64 + 2)/66 = 100%
Trang 11Table 3.8 Comparison of lymph node metastasis between
computed tomography and pathology
Total 20(30.30) 12(18.18) 25(37.88) 8(12.12) 1(1.52) 66(100)
Comment: Accurate diagnosis rate of abdominal CT scan indiagnosing metastasis in gastric cancer lymph nodes:(13+9+17+2)/66 = 62.12% Sensitivity corresponding to thediagnosis of lymph node metastasis and the degree of lymph nodemetastasis, respectively: N: 36/46 = 78.26%; N1: 9/12 = 75.00%; N2:17/25 = 68.00%; N3: 2/9 = 22.22% The specificity corresponding tothe diagnosis of lymph node metastasis and the degree of lymph nodemetastasis, respectively: N: 13/20 = 65.00%; N1: 47/54 = 87.04%;N2: 35/41 = 85.37%; N3: 55/57 = 96.49% The positive predictivevalue corresponds to the diagnosis of lymph node metastasis and thedegree of lymph node metastasis, respectively: N: 36/43 = 83.72%;N1: 9/16 = 56.25%; N2: 17/23 = 73.91%; N3: 2/2 = 50.00% Thenegative predictive value corresponds to the diagnosis of lymph nodemetastasis and the degree of lymph node metastasis, respectively: N:13/23 = 56.52%; N1: 47/50 = 94.00%; N2: 35/43 = 81.40%; N3:55/62 = 88.71% The accuracy corresponding to the diagnosis oflymph node metastasis and the degree of lymph node metastasis,respectively: N: 49/66 = 74.24%; N1: 56/66 = 84.85%; N2: 52/66 =78.79%; N3: 57/66 = 86.36%
Trang 12Table 3.9 Comparison of disease stage between computed
tomography and pathology
3 (4.55)
Ib (11.11
1)
5 (55.5 6)
1 (11.1 1)
1 (11.1 1)
0 (0.00)
1 (11.1 1)
0 (0.00)
0 (0.00 )
9 (13.64 ) IIa (0.0)0 (6.25)1
6 (37.5 0)
2 (12.5 0)
4 (25.0 0)
1 (6.25)
2 (12.5 0)
0 (0.00 )
16 (24.24 ) IIb (0.00)0
3 (20.0 0)
1 (6.67)
10 (66.6 7)
0 (0.00)
1 (6.67)
0 (0.00)
0 (0.00 )
15 (22.73 ) IIIa (0.00)0 (0.00)0 (0.00)0
1 (10.0 0)
5 (50.0 0)
1 (10.0 0)
3 (30.0 0)
0 (0.00 )
10 (15.15 ) IIIb (0.00)0 (0.00)0 (0.00)0
1 (14.2 9)
1 (14.2 9)
1 (14.2 9)
4 (57.1 4)
0 (0.00 )
7 (10.61 ) IIIc (0.00)0 (0.00)0 (0.00)0
1 (25.0 0)
0 (0.00)
1 (25.0 0)
2 (50.0 0)
0 (0.00 )
4 (6.06)
IV (0.00)0 (0.00)0 (0.00)0 (0.00)0 (0.00)0 (0.00)0 (0.00)0 (1002
)
2 (3.03)
Tota
l (6.06)4
9 (13.6 4)
8 (12.1 2)
16 (24.2 4)
10 (15.1 5)
6 (9.09)
11 (16.6 7)
2 (3.03 )
66 (100)
Comment: Accurate diagnosis rate of abdominal CT scan indiagnosing gastric cancer stage: (3+5+6+10+5+1+2+2)/66 = 51.52%.Sensitivity corresponding to disease stages, respectively: Ia: 3/4 =75.00%; Ib: 5/9 = 55.56%; IIa: 6/8 = 75.00%; IIb: 10/16 = 62.50%;IIIa: 5/10 = 50.00%; IIIb: 1/6 = 16.67%; IIIc: 2/11 = 18.18%; IV: 2/2
= 100.00% Specificity corresponding to the disease stagesrespectively: Ia: 62/62 = 100.00%; Ib: 53/57 = 92.98%; IIa: 48/58 =82.76%; IIb: 45/50 = 90.00%; IIIa: 51/56 = 91.07%; IIIb: 54/60 =90.00%; IIIc: 53/55 = 96.36%; IV: 64/64 = 100.00% Positivepredictive value corresponding to the disease stages respectively: Ia:3/3 = 100.00%; Ib: 5/9 = 55.56%; IIa: 6/16 = 37.50%; IIb: 10/15 =