The purpose of this study was to analyze the value of transrectal shear-wave elastography (SWE) in combination with multivariable tools for predicting adverse pathological features before radical prostatectomy (RP). Preoperative clinicopathological variables, multiparametric magnetic resonance imaging (mp-MRI) manifestations, and the maximum elastic value of the prostate (Emax) on SWE were retrospectively collected. The accuracy of SWE for predicting adverse pathological features was evaluated based on postoperative pathology, and parameters with statistical significance were selected. The diagnostic performance of various models, including preoperative clinicopathological variables (model 1), preoperative clinicopathological variables + mp-MRI (model 2), and preoperative clinicopathological variables + mp-MRI + SWE (model 3), was evaluated with area under the receiver operator characteristic curve (AUC) analysis. Emax was significantly higher in prostate cancer with extracapsular extension (ECE) or seminal vesicle invasion (SVI) with both P < 0.001. The optimal cutoff Emax values for ECE and SVI were 60.45 kPa and 81.55 kPa, respectively. Inclusion of mp-MRI and SWE improved discrimination by clinical models for ECE (model 2 vs model 1, P = 0.031; model 3 vs model 1, P = 0.002; model 3 vs model 2, P = 0.018) and SVI (model 2 vs model 1, P = 0.147; model 3 vs model 1, P = 0.037; model 3 vs model 2, P = 0.134). SWE is valuable for identifying patients at high risk of adverse pathology.
Male ; Humans ; Prostate/pathology* ; Seminal Vesicles/diagnostic imaging* ; Elasticity Imaging Techniques ; Retrospective Studies ; Extranodal Extension/pathology* ; Neoplasm Staging ; Prostatectomy/methods* ; Prostatic Neoplasms/pathology* ; Magnetic Resonance Imaging/methods*

At present, preoperative assessment of rectal cancer stage mainly relies on imaging examination, and the results of imaging reading will directly determine the treatment. In order to alleviate the reading pressure of the radiologist and improve the efficiency and accuracy of imaging diagnosis, there are related studies on using artificial intelligence automatic recognition system to assist the imaging assessment of rectal cancer staging now. Colorectal Surgery Group, Chinese Society of Surgery of the Chinese Medical Association, along with Beihang University, proposed the expert's advice on the surgical clinical application of rectal cancer staging recognition system based on artificial intelligence platform, so as to guide the standard application of this technology and promote the automation and intelligence of imaging reading.
Artificial Intelligence ; Diagnostic Imaging ; Digestive System Surgical Procedures ; Humans ; Magnetic Resonance Imaging ; Neoplasm Staging ; Rectal Neoplasms/surgery*

The International Agency for Research on Cancer (IARC) published the World Health Organization (WHO) classification of thoracic tumors (5th edition) in May 2021, only six years after the 4th edition of WHO Classification. With the application of low-dose spiral computed tomography (CT) as an early screening method for lung tumors in recent years, lung adenocarcinoma has become the main type of disease in many hospital surgical treatments. The WHO classification serves as the authoritative guide for pathological diagnosis, and any slight change in the classification is at the heart of pathologists, clinicians and patients. Adenocarcinoma in situ is a newly added type of adenocarcinoma diagnosis in the 4th edition of the WHO classification, and it is also the focus of clinical treatment and research at home and abroad in recent years. Because its catalog position has been adjusted in the 5th edition of the WHO classification, there has been a huge controversy and discussion among clinicians and patients that "adenocarcinoma in situ was excluded from the category of malignant tumors". This article will briefly explain the origin of the diagnosis of lung adenocarcinoma in situ, the adjustment of the new classification catalog, and whether adenocarcinoma in situ is benign or malignant.
.
Adenocarcinoma in Situ/pathology* ; Adenocarcinoma of Lung/diagnostic imaging* ; Humans ; Lung Neoplasms/pathology* ; Neoplasm Staging

OBJECTIVE: To evaluate the performance of 3.0T magnetic resonance imaging examination (MRI) for the local detecting of muscle invasive bladder cancer following transurethral resection of bladder tumor (TURBT). METHODS: Retrospective study identified 55 patients with pathology-proven bladder cancer who underwent transurethral resection of bladder tumor followed by 3.0T magnetic resonance imaging between September 2012 and April 2019 in our hospital. Two radiologists reviewed pelvic magnetic resonance imaging together and judged muscle invasive bladder cancer. Sensitivity, specificity and accuracy were calculated for the presence of muscle invasion by T2 weighted imaging (T2WI) only, diffusion-weighted imaging (DWI) only and T2WI+DWI compared with the findings at radical cystectomy as the reference standard. RESULTS: Of the 55 patients with pathological results from radical cystectomy, 3.64% (2/55) had no residual disease; 29.09% (16/55) were non-muscle invasive bladder cancer on pathology, including 13 cases in T1 and 3 cases in Ta; 34.55% (19/55) were in stage T2 depending on pathology, 25.45% (14/55) in T3, and 7.27% (4/55) in T4. The average age was 60.76 years, ranging from 42 to 82 years. There were 48 males and 7 females in our study. Before pelvic MRI examination, all the patients received transurethral resection of bladder tumor, including 16 cases taking the operation in our hospital and 39 cases in other hospitals. The interval between the pelvic MRI examination and transurethral resection of bladder tumor was more than 2 weeks in all the patients. They all underwent radical cystectomy within 1 month after the pelvic MRI examination, and no patient underwent radiotherapy or chemotherapy in our study during the interval between the MRI examination and radical cystectomy. T2WI only, DWI only, and T2WI+DWI of 3.0T magnetic resonance imaging for readers were with sensitivity: 94.59%, 83.78%, 91.89%; with specificity: 66.67%, 77.78%, 72.22% and with accuracy: 85.45%, 81.82%, 85.45%, respectively. CONCLUSION 3.0T MRI may have a role in diagnosing muscle invasive bladder cancer following TURBT. T2WI has the advantage of detecting the location of bladder tumor, and DWI has the advantage of differentiating between the benign and malignant lesion. 3.0T MRI T2WI+DWI has a good utility in the detection of muscle invasive bladder cancer following TURBT with satisfied accuracy.
Adult ; Aged ; Aged, 80 and over ; Cystectomy ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neoplasm Staging ; Retrospective Studies ; Urinary Bladder Neoplasms/diagnostic imaging*

BACKGROUND: An artificial intelligence system of Faster Region-based Convolutional Neural Network (Faster R-CNN) is newly developed for the diagnosis of metastatic lymph node (LN) in rectal cancer patients. The primary objective of this study was to comprehensively verify its accuracy in clinical use. METHODS: Four hundred fourteen patients with rectal cancer discharged between January 2013 and March 2015 were collected from 6 clinical centers, and the magnetic resonance imaging data for pelvic metastatic LNs of each patient was identified by Faster R-CNN. Faster R-CNN based diagnoses were compared with radiologist based diagnoses and pathologist based diagnoses for methodological verification, using correlation analyses and consistency check. For clinical verification, the patients were retrospectively followed up by telephone for 36 months, with post-operative recurrence of rectal cancer as a clinical outcome; recurrence-free survivals of the patients were compared among different diagnostic groups, by methods of Kaplan-Meier and Cox hazards regression model. RESULTS: Significant correlations were observed between any 2 factors among the numbers of metastatic LNs separately diagnosed by radiologists, Faster R-CNN and pathologists, as evidenced by rradiologist-Faster R-CNN of 0.912, rPathologist-radiologist of 0.134, and rPathologist-Faster R-CNN of 0.448 respectively. The value of kappa coefficient in N staging between Faster R-CNN and pathologists was 0.573, and this value between radiologists and pathologists was 0.473. The 3 groups of Faster R-CNN, radiologists and pathologists showed no significant differences in the recurrence-free survival time for stage N0 and N1 patients, but significant differences were found for stage N2 patients. CONCLUSION: Faster R-CNN surpasses radiologists in the evaluation of pelvic metastatic LNs of rectal cancer, but is not on par with pathologists. TRIAL REGISTRATION www.chictr.org.cn (No. ChiCTR-DDD-17013842).
Adult ; Aged ; Aged, 80 and over ; Artificial Intelligence ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Neural Networks (Computer) ; Pathologists ; Radiologists ; Rectal Neoplasms ; diagnostic imaging ; mortality ; pathology

The accurate judgement of the upper and lower borders of the adenocarcinoma of esophagogastric junction (AEG) by radiology can facilitate the decisions on surgical approach and staging criteria. X-ray double contrast radiography, CT and MRI are the common modalities. The accuracy of X-ray double contrast radiography in determining the invasion length of esophagus and the central point of gastric infiltration can be improved by standardized pretreatment, combination of multiple contrast methods such as double contrast and flow-coating procedure, and combination of multi-angle observations such as conventional frontal, left /right anterior oblique and supine right posterior oblique position. Abdominal enhanced CT is the imaging method recommended by clinical guidelines for the radiological examination of AEG. The relative position of the central point of the tumor from 2 cm line can be determined through the combination of measurement and formula calculation on multi-planar reconstructed CT images. The "three-layer four-type" classification can provide reference for the selection of abdominothoracic incision. The direct demonstration of the tumor extension can be achieved through the CT curved planar reconstruction by drawing lines along esophagus to stomach. The combination of multiple sequences of MRI is helpful to determine the extension of the lesions. In the future, more radiological studies are needed to establish criteria with high accuracy, repeatability and convenient operation,and to assist clinical evaluation of AEG invasion.
Adenocarcinoma ; classification ; diagnostic imaging ; pathology ; surgery ; Contrast Media ; Esophageal Neoplasms ; classification ; diagnostic imaging ; pathology ; surgery ; Esophagogastric Junction ; diagnostic imaging ; pathology ; surgery ; Humans ; Magnetic Resonance Imaging ; Neoplasm Invasiveness ; Neoplasm Staging ; Stomach Neoplasms ; classification ; diagnostic imaging ; pathology ; surgery ; Tomography, X-Ray Computed

BACKGROUND: Pneumonic-type lung carcinoma is a special type of lung cancer both clinically and radiologically. Here we present our experience on pneumonic-type lung carcinoma in an attempt to investigate the clinical, radiological and pathological features, diagnostic procedures, treatment, and prognosis of this type of tumor. METHODS: Pathologically confirmed lung cancer with a chest CT characterized by ground glass opacity or consolidation was defined as pneumonic-type lung carcinoma. Cases with advanced pneumonic-type lung carcinoma admitted to Peking Union Medical College Hospital (PUMCH) from January 1, 2013 to August 30, 2018 were enrolled. Retrospective analysis of clinical data and survival follow-up of these patients was conducted. RESULTS: A total of 46 cases were enrolled, all of which were adenocarcinoma. Cough (41/46, 89.1%) and expectoration (35/46, 76.1%) were the most prominent symptoms. The most frequent chest CT findings were ground glass attenuation (87.0%), patchy consolidation (84.8%), and multiple ground-glass nodules (84.8%). Multiple cystic changes (40%) and cavitation (13%) were also quite frequent. Ipsilateral and contralateral intrapulmonary metastasis were noted in 95.3% and 84.8% of cases respectively. The median duration from symptom onset to diagnosis was 214 days (95%CI: 129-298). Both surgical lung biopsy and CT-guided percutaneous lung biopsy had a diagnostic yield of 100%. Transbronchial lung biopsy (TBLB) combined with bronchoalveolar lavage (BAL) had a diagnostic yield of 80.9% (17/21). Sputum cytology had a diagnostic yield of 45% (9/20). Twenty-six cases were invasive mucinous adenocarcinoma (26/46, 56.5%) and the remainder were unable to identify pathological subtypes due to lack of adequate biopsy sample size. EGFR mutation was detected in 15.8% (6/38) of patients and ALK rearrangement was detected in 3.0% (1/33) of patients. The median overall survival for these patients was 522 d (95%CI: 424-619). In patients without EGFR mutation or ALK rearrangement, chemotherapy significantly improved survival (HR=0.155, P=0.002,2). The median overall survival was 547 d (95%CI: 492-602 d) with chemotherapy and 331 d (95%CI: 22-919) without chemotherapy. CONCLUSIONS Diagnosis of pneumonic-type carcinoma is usually delayed due to clinical and radiological features mimicking pulmonary infection. TBLB combined with BAL has a quite high diagnostic yield. The most frequent histological type is invasive mucinous adenocarcinoma. The incidence of EGFR mutation or ALK rearrangement is low in pneumonic-type carcinoma. For patients without cancer driver genes, chemotherapy is recommended to improve overall survival.
Aged ; Anaplastic Lymphoma Kinase ; genetics ; metabolism ; Antineoplastic Agents ; therapeutic use ; Carcinoma ; diagnostic imaging ; drug therapy ; genetics ; pathology ; ErbB Receptors ; genetics ; metabolism ; Female ; Gene Rearrangement ; Humans ; Lung Neoplasms ; diagnostic imaging ; drug therapy ; genetics ; pathology ; Male ; Middle Aged ; Mutation ; Neoplasm Staging ; Retrospective Studies ; Survival Analysis ; Tomography, X-Ray Computed

OBJECTIVETo investigate the value of preoperative abdominal contrast-enhanced multiple-row detector computed tomography (ceMDCT) in predicting the postoperative 1-year disease-free survival (DFS) for gastric cancer.

METHODSBetween January 2009 and December 2015, 237 gastric cancer patients at Peking University People's Hospital with complete preoperative clinical, image and follow-up data were enrolled in this retrospective study.

INCLUSION CRITERIA(1) primary gastric cancer was confirmed by pathology; (2) radical gastrectomy and D2 lymph node dissection were performed;(3) patients underwent preoperative ceMDCT. Patients with gastric stump cancer, concurrent metastasis, other malignancies, and undergoing neoadjuvant treatment were excluded. According to ceMDCT examination with or without ctEMVI (extramural venous invasion), patients were divided into ctEMVI-positive and ctEMVI-negative group. ctEMVI-positive was defined as that there was a continuous tubular and nodular soft tissue filling defect from the tumor to the adjacent blood vessel lumen in ceMDCT, suggesting the tumor directly invaded the blood vessels outside the muscularis propria of the gastrointestinal smooth muscle. Log-rank test was used to compare differences in 1-year DFS between ctEMVI-positive group and ctEMVI-negative group. According to the 8th edition of the American Joint Committee on Cancer (AJCC), the T staging in ceMDCT (ctT) and lymph node metastasis (lymph nodes with shorter diameter > 8 mm) were determined. The patients were subdivided into four subgroups, ctT4N(+), ctT4N(-), ctT1-3N(+), and ctT1-3N(-), to further compare the difference in postoperative 1-year DFS between ctEMVI-positive and -negative patients in each subgroups. Kaplan-Meier univariate analysis was performed on preoperative imaging data (ctT, ctN, ctEMVI, tumor location/growth pattern, and ctSize). Cox proportional hazard regression was used to find the independent risk factors of 1-year DFS rate. According to the number of independent risk factors, the patients were classified to different risk stratifications. The difference of 1-year DFS rate between different risk stratifications was compared.

RESULTSAccording to the results of ceMDCT, 72 patients (30.4%) were divided into the ctEMVI-positive group and 165 patients(69.6%) into the ctEMVI-negative group. The ctEMVI-positive group had significantly lower 1-year DFS rate (55.3%) than the ctEMVI-negative group (90.2%) (χ²=40.17, P<0.001). The 1-year DFS in the ctEMVI-positive ctT4N(+) subgroup was 34.5%, which was significantly lower than that of the ctMVI-negative ctT4N(+) subgroup (85.3%) (χ²=19.13, P<0.001). In the ctEMVI-positive ctT1-3N(-) subgroup, the 1-year DFS was 77.8%, which was also significantly lower than 98.5% of the ctEMVI-negative ctT1-3N(-) subgroup(χ²=15.09, P=0.003). In Cox proportional hazards regression analysis, ctT, ctN and ctEMVI were identified as independent prognostic factors of 1-year DFS with hazard ratio (HR) of 3.351(95%CI:1.249-8.986, P=0.017), 1.987(95%CI:1.085-3.637, P=0.027) and 3.398(95%CI:1.785-6.469, P<0.001), respectively. Risk classification was carried out according to the number of independent risk factors (ctT, ctN and ctEMVI). Grade 0 had no independent risk factors, grade 1 had one independent risk factor, grade 2 had two independent factors and grade 3 had 3 independent risk factors. The risk grading result showed that the numbers of patients form grade 0 to 3 were 71, 65, 68, 33, respectively, and the 1-year DFS rates were 98.5%, 82.1%, 79.0%, 34.5%, respectively(P<0.001). With the increase of the number of independent risk factors, 1-year DFS rate decreased gradually in patients with gastric cancer (P<0.001). Differences of 1-year DFS between grade 0 and grade 1(P=0.002), between grade 2 and grade 3(P<0.001) were both significant. Meanwhile the difference between grade 1 and grade 2 was not significant (P=0.578).

CONCLUSIONSctEMVI, ctT and ctN defined by preoperative ceMDCT are independent risk factors for the prognosis of gastric cancer. With the increase of risk factors, the 1-year DFS decreases gradually.

Disease-Free Survival ; Gastrectomy ; Humans ; Neoplasm Invasiveness ; Neoplasm Staging ; Prognosis ; Proportional Hazards Models ; Retrospective Studies ; Stomach Neoplasms ; diagnostic imaging ; surgery ; Survival Rate ; Tomography, X-Ray Computed

OBJECTIVETo explore the application value of texture analysis of magnetic resonance images (MRI) in predicting the efficacy of neoadjuvant chemoradiotherapy(nCRT) for rectal cancer.

METHODSA total of 34 rectal cancer patients who were hospitalized at Zhejiang Provincial People's Hospital from February 2015 to April 2017 were prospectively enrolled and received 3.0T MRI examination at pre-nCRT (1 day before nCRT), early stage (at 10-day after nCRT) and middle stage (at 20-day after nCRT).

INCLUSION CRITERIAdistance from tumor lower margin to anal edge was less than 12 cm under rectoscope; rectal cancer was confirmed by preoperative pathology; clinical stage was T3 or above; lymph node metastasis existed but without distant metastasis; functions of liver, kidney and heart present no contraindications of operation.

EXCLUSION CRITERIAunfinished nCRT, surgery and three examinations of MRI; image motion artifacts; lack of postoperative pathological results. All the patients underwent rectal cancer long-term three-dimensional radiotherapy and chemotherapy combined with nCRT (oxaliplatin plus capecitabine). The tumor regression grading (TRG) was divided into TRG 0 to 4 grade after nCRT, and TRG 4 was classified as pathological complete remission (pCR); TRG 2 to 3 was classified as partial remission (PR); the rest was no remission (NR). Extraction and analysis of texture features in T2-weighted MR-defined tumor region were performed using Omni Kinetics texture software. The texture values of each time point were statistically analyzed, and the differences of texture values and change differences between pCR and PR+NR, and NR and pCR+PR were compared respectively. Statistically significant texture values were screened and were used in receiver operating characteristic (ROC) curve to assess the prediction of the efficacy of nCRT.

RESULTSOf 34 patients, 21 were males and 13 were females with median age of 49.3 years. Nineteen (55.9%) patients were low rectal adenocarcinoma and 15 (44.1%) patients were middle rectal adenocarcinoma. Nine (26.5%) cases belonged to pCR, 13 (38.2%) belonged to PR, and 12 (35.3%) belonged to NR. Before nCRT, the entropy of tumor area in pCR patients was significantly higher than that in PR+NR patients (7.164±0.272 vs. 6.823±0.309, t=2.925, P=0.006). At the middle stage of nCRT, as compared with PR+NR patients for the texture features of tumor region, the variance (1566±281 vs. 2883±867, t=-4.435, P=0.000) and entropy(5.436±0.934 vs. 6.803±0.577, t=-4.118,P=0.002) of pCR patients were significantly lower; kurtosis(4.800±1.288 vs. 3.206±1.211, t=3.333, P=0.002) and energy (0.016±0.005 vs. 0.010±0.004, t=3.240, P=0.003) of pCR patients were significantly higher. As compared to pCR+PR patients, the kurtosis(2.461±0.931 vs. 4.264±1.205, t=-4.493, P=0.000) and energy (0.011±0.004 vs. 0.014±0.004, t=-3.453, P=0.000) of the NR patients were significantly lower. As for texture change values between early stage and middle stage, the entropy difference was significant between pCR and PR+NR, NR and pCR+PR (1.344±0.819 vs. 0.489±0.319, t=3.047, P=0.014; 0.446±0.213 vs. 0.917±0.677, t=-3.638, P=0.001, respectively). As for texture change values between pre-nCRT and middle stage, variance and entropy differences between pCR and PR+NR (1759±1226 vs. 977±842, t=2.113, P=0.042; 1.728±0.918 vs. 0.524±0.355, t=3.832, P=0.004), and the change values of entropy between NR and pCR+PR (0.475±0.349 vs. 1.044±0.860, t=-2.722, P=0.011) were statistically significant. The above indicators were included in the ROC curve. The results revealed that at the middle stage, entropy value >5.983 indicated the best efficacy for the diagnosis of pCR, with the area under the ROC curve (AUC) of 0.885, the sensitivity of 100%, and the specificity of 66.7%; the energy <0.010 indicated the best AUC for diagnosis of NR was 0.902, with the sensitivity of 91.7% and specificity of 81.8%.

CONCLUSIONSTexture analysis based on T2 weighted images can predict the efficacy of nCRT for rectal cancer. The middle stage of nCRT is the best time of prediction. The entropy and energy of this period are texture parameters having higher predictive ability.

Chemoradiotherapy ; Female ; Humans ; Magnetic Resonance Spectroscopy ; Male ; Middle Aged ; Neoadjuvant Therapy ; Neoplasm Staging ; Predictive Value of Tests ; Prognosis ; Rectal Neoplasms ; diagnostic imaging ; therapy ; Treatment Outcome

OBJECTIVETo investigate the accuracy of CT in preoperative discrimination of cT3 from cT4 in patients with Siewert II esophagogastric junction (EGJ) adenocarcinoma according to UICC/AJCC 8th edition and IGCA 4th edition.

METHODSCT imaging data of 43 consecutive patients with Siewert II EGJ adenocarcinoma who underwent preoperative CT and were diagnosed as pT3 or pT4 by postoperative pathology were retrospectively analyzed. Inclusion criteria were as follows:(1)no previous history of gastric operation, radiochemotherapy, targeted treatment; no contraindications of CT enhanced scanning; (2) good filling of gastric cavity by CT, clear image without artifacts, all axial-coronal-sagittal 3-plane reconstruction images obtained by abdominal stage 3 enhanced scan; (3) operation within 1 week after CT examination; (4) Siewert II EGJ adenocarcinoma confirmed by operation, pT3 and pT4 by postoperative pathology. Transverse and multiplanar reconstruction images were reviewed by two radiologists in double-blind method. Distance between cancer epicenter and esophagogastric junction line, and the contour of the serosa were retrospectively measured on CT scans. The cT staging judgment was performed according to the UICC/AJCC 8th edition (Siewert II EGJ adenocarcinoma should be staged as esophageal cancer) and IGCA 4th edition (Siewert II EGJ adenocarcinoma should be staged as gastric cancer) respectively. Consistency of cT staging and pathological pT staging was compared between UICC/AJCC and IGCA.

RESULTSPreoperative CT revealed that the mean length between tumor epicenter and esophagogastric junction line was(1.5±0.4) cm (0.7-2.5 cm), and such length was ≤2 cm in 41 cases, whose concordance with surgical judgment was 95.3%(41/43). IGCA staging: 18 cases were preoperatively assessed as cT3 and 25 cases as cT4a. UICC/AJCC staging: 41 cases with cancer epicenter locating within 2 cm below esophagogastric junction line were staged as cT3 according to esophageal cancer staging; 2 cases with cancer epicenter locating > 2 cm below esophagogastric junction line were staged according to gastric cancer staging, of whom one was staged as cT3 due to regular serosa and the other was staged as cT4a due to irregular serosa. Postoperative pathology: 33 cases were pT3 and 10 cases were pT4a. The accuracy of preoperative CT in discrimination of T3 from T4a was 74.4%(32/43) with UICC/AJCC criteria and 65.1%(28/43) with IGCA criteria, whose difference was significant(P<0.01).

CONCLUSIONSPreoperative CT can accurately localize the 2 cm threshold line of Siewert II esophagogastric junction adenocarcinoma, which is beneficial to the discrimination of cT3 from cT4a EGJ adenocarcinoma. Application of the UICC/AJCC 8th edition criteria to above discrimination has higher accuracy as compared to IGCA 4th edition in cT-staging by CT.

Adenocarcinoma ; Double-Blind Method ; Esophageal Neoplasms ; diagnostic imaging ; Esophagogastric Junction ; Humans ; Neoplasm Staging ; Retrospective Studies ; Stomach Neoplasms ; diagnostic imaging ; Tomography, X-Ray Computed