[Application of Automated Machine Learning Based on Radiomics Features of T2WI and RS-EPI DWI to Predict Preoperative T Staging of Rectal Cancer].

OBJECTIVE: To explore the radiomics features of T2 weighted image (T2WI) and readout-segmented echo-planar imaging (RS-EPI) plus difusion-weighted imaging (DWI), to develop an automated mahchine-learning model based on the said radiomics features, and to test the value of this model in predicting preoperative T staging of rectal cancer. METHODS: The study retrospectively reviewed 131 patients who were diagnosed with rectal cancer confirmed by the pathology results of their surgical specimens at West China Hospital of Sichuan University between October, 2017 and December, 2018. In addition, these patients had preoperative rectal MRI. Tumor regions from preoperative MRI were manually segmented by radiologists with the ITK-SNAP software from T2WI and RS-EPI DWI images. PyRadiomics was used to extract 200 features-100 from T2WI and 100 from the apparent diffusion coefficient (ADC) calculated from the RS-EPI DWI. MWMOTE and NEATER were used to resample and balance the dataset, and 13 cases of T 1-2 stage simulation cases were added. The overall dataset was divided into a training set (111 cases) and a test set (37 cases) by a ratio of 3∶1. Tree-based Pipeline Optimization Tool (TPOT) was applied on the training set to optimize model parameters and to select the most important radiomics features for modeling. Five independent T stage models were developed accordingly. Accuracy and the area under the curve ( AUC) of receiver operating characteristic (ROC) were used to pick out the optimal model, which was then applied on the training set and the original dataset to predict the T stage of rectal cancer. RESULTS: The performance of the the five T staging models recommended by automated machine learning were as follows: The accuracy for the training set ranged from 0.802 to 0.838, sensitivity, from 0.762 to 0.825, specificity, from 0.833 to 0.896, AUC, from 0.841 to 0.893, and average precision (AP) from 0.870 to 0.901. After comparison, an optimal model was picked out, with sensitivity, specificity and AUC for the training set reaching 0.810, 0.875, and 0.893, respectively. The sensitivity, specificity and AUC for the test set were 0.810, 0.813, and 0.810, respectively. The sensitivity, specificity and AUC for the original dataset were 0.810, 0.830, and 0.860, respectively. CONCLUSION: Based on the radiomics data of T2WI and RS-EPI DWI, the model established by automated machine learning showed a fairly high accuracy in predicting rectal cancer T stage.

Hand-assisted laparoscopic right hemicolectomy with complete mesocolic excision and central vascular ligation: a novel technique for right colon cancer.

BACKGROUND: It can be difficult to locate the superior mesenteric vein and dissect around middle colic vessels during laparoscopic right hemicolectomy with complete mesocolon excision due to a high rate of vascular variations in the superior mesenteric vessels. Therefore, we report a modified technique for hand-assisted laparoscopic right hemicolectomy with complete mesocolic excision and central vascular ligation, which addresses these two problems. METHODS: Thirty-one consecutive patients with right colon cancer underwent this procedure from March 2014 to August 2015. Extracorporeally, the transverse colon and distal ileum were excised with a transumbilical hand-port incision, and the distal part of the superior mesenteric vein was identified. Intracorporeally, with the assistance of the surgeon's left hand inserted through the incision, D3-lymphadenectomy with central vascular ligation was performed, and the colon with the tumor, which had no blood supply, was removed. Patients' demographic data and intraoperative, postoperative and pathological characteristics were examined. RESULTS: The median operative time was 130.0 (range 115-180) minutes. The median blood loss was 45.0 (range 20-300) milliliters. The median length of the hand-port incision was 7.3 (range 6.0-8.2) centimeters. The median numbers of lymph nodes and central lymph nodes was 34.0 (range 18-91) and 13.0 (range 3-28), respectively. Five (16.1%) of 31 patients had positive central lymph nodes. Specimen morphometric quantitation was as follows: the median distances from the tumor and nearest bowel wall to the high tie were 10.5 (range 5.0-15.0) and 8.0 (range 6.0-12.0) centimeters, respectively; the median resected area of the mesentery was 200.0 (range 96.0-300.0) square centimeters; the median width of the chain of lymph-adipose tissue at the central lymph nodes area was 2.0 (range 0.8-8.0) centimeters; and the median length of the central lymph-adipose chain was 19.0 (range 3.0-26.0) centimeters. CONCLUSIONS: Our procedure confers technical advantages and is feasible for treatment of right colon cancer.

Association between RAD51 gene polymorphism (-135G/C) and susceptibility of myelodysplastic syndrome and acute leukemia: evidence based on a meta-analysis.

Study results on the association between RAD51 gene -135G/C polymorphism and risk of myelodysplastic syndrome (MDS) or acute leukemia are inconsistent. A meta-analysis was conducted to identify the association. A systematic search was performed in PubMed, Embase, CNKI, VIP, Wanfang databases to collect all relevant studies until January 2013. Meta-analysis was carried out using fixed/random model by Review Manager 5.1 and STATA10.0. A total of 10 eligible studies with 2,656 patients and 3,725 controls were included in meta-analysis. Significant association was detected between -135G/C polymorphism and increased MDS risk (CC + GC vs. GG: OR = 1.46, 95% CI = 1.11-1.92; CC vs. GC + GG: OR = 2.45, 95% CI = 1.23-4.89), while no association was observed for acute leukemia. Subgroup analysis by subtypes of acute leukemia and ethnicity showed no significant results either. Our meta-analysis indicated that the -135G/C polymorphism might be associated with increased susceptibility of MDS. However, lack of evidence supported association of this polymorphism with acute leukemia. Additional well-designed studies with larger samples are required to verify our results.

NBS1 Glu185Gln polymorphism and cancer risk: update on current evidence.

A number of studies have investigated the association between NBS1 Glu185Gln (rs1805794, E185Q) polymorphism and cancer risk, but the results remained controversial. Previous meta-analysis found a borderline significant impact of this polymorphism on cancer risk; however, the result might be relatively unreliable due to absence of numerous newly published studies. Thus, we conducted an updated meta-analysis. A systematic search was performed in PubMed and Embase databases until April 9, 2013. The odds ratios were pooled by the fixed-effects/random-effects model in STATA 12.0 software. As a result, a total of 48 case-control studies with 17,159 cases and 22,002 controls were included. No significant association was detected between the Glu185Gln polymorphism and overall cancer risk. As to subgroup analysis by cancer site, the results showed that this polymorphism could increase the risk for leukemia and nasopharyngeal cancer. Notably, the Glu185Gln polymorphism was found to be related to increased risk for urinary system cancer, but decreased risk for digestive system cancer. No significant associations were obtained for other subgroup analyses such as ethnicity, sample size and smoking status. In conclusion, current evidence did not suggest that the NBS1 Glu185Gln polymorphism was associated with overall cancer risk, but this polymorphism might contribute to the risk for some specific cancer sites due to potential different mechanisms. More well-designed studies are imperative to identify the exact function of this polymorphism in carcinogenesis.

Short-Term and Long-Term Outcomes of Laparoscopic Versus Open Surgery for Low Rectal Cancer.

AIM: To compare the short-term and long-term outcomes of laparoscopic versus open surgery for low rectal cancer. METHODS: Patients with low rectal cancer who underwent laparoscopic or open surgery at our department from January 2009 to December 2013 were enrolled in this retrospective study. The primary end points were 3-year local recurrence and overall and disease-free survival (DFS) rates. Secondary end points were intraoperative and postoperative outcomes. RESULTS: Laparoscopic group had longer operative time (165.0 versus 140.0, P < .001), less blood loss (20.0 versus 40.0, P < .001), shorter length of incision (5.0 versus 18.0, P < .001), and more lymph node harvested (11.0 versus 9.0, P = .002). However, time to first flatus (P = .941), postoperative hospital stay (P = .095), postoperative complications (P = .155), and 30-day mortality (P = .683) was similar between two groups. With the median follow-up period of 65 months, the 3-year local recurrence rate was 4.3% in laparoscopic group and 7.5% in open group (P = .077); the 3-year overall and DFS rates were similar in two groups (85.9% versus 88.8%, P = .229 and 76.9% versus 79.2%, P = .448, respectively); and the overall and DFS curves were comparable between two groups (hazard ratio [HR] = 0.858, 95% confidence intervals [CI] 0.709-1.037, P = .112 and HR = 1.076, 95% CI 0.834-1.389, P = .275, respectively). CONCLUSIONS: Laparoscopic surgery is safe and has equivalent long-term oncologic outcomes for low rectal cancer when compared to open surgery. Furthermore, large-scale, prospective randomized clinical trials are needed to confirm the present findings.

Readout-segmented echo-planar diffusion-weighted MR for the evaluation of aggressive characteristics of rectal cancer.

To evaluate whether aggressive characteristics of rectal cancer can be predicted by the apparent diffusion coefficient (ADC) obtained using readout-segmented echo-planar imaging (rs-EPI) diffusion-weighted magnetic resonance. We enrolled one hundred and fifteen patients. The image quality of ADC maps by rs-EPI was compared with that by traditional single-shot echo-planar imaging (ss-EPI), and ADC measurement was performed on the rs-EPI based ADC maps. Differences in ADC values of tumors grouped according to differentiation grade, clinical T stage and plasmatic carcinoembryonic antigen (CEA) level were tested. The correlation between each aggressive characteristic and the corresponding ADC values was evaluated. The image quality of ADC maps obtained by rs-EPI was superior toss-EPI (P < 0.05). The ADC values of tumor were categorized based on the following differentiation grades: poor (0.89 ± 0.12 × 10-3 mm2/s), moderate (1.13 ± 0.25 × 10-3 mm2/s), and good (1.31 ± 0.19 × 10-3 mm2/s); P < 0.001. Tumors with lower differentiation grades corresponded to lower ADC values (r = 0.59, P < 0.001). However, ADC differences were not observed in different clinical T stage (P = 0.22) and plasmatic CEA level (P = 0.38). Rs-EPI sequence-based ADC values represent a potential imaging marker for the aggressive rectal cancer characteristics.

Readout-segmented echo-planar imaging improves the image quality of diffusion-weighted MR imaging in rectal cancer: Comparison with single-shot echo-planar diffusion-weighted sequences.

PURPOSE: To determine whether readout-segmented echo-planar imaging (rs-EPI) diffusion-weighted imaging (DWI) can improve the image quality in patients with rectal cancer compared with single-shot echo-planar imaging (ss-EPI) DWI using 3.0 T magnetic resonance (MR) imaging. MATERIALS AND METHODS: This study was approved by the Institutional Review Board, and informed consent was obtained from all patients. Seventy-one patients with rectal cancer were enrolled in this study. For all patients, both rs-EPI and ss-EPI DWI were performed using a 3T MR scanner. Two radiologists independently assessed the overall image quality, lesion conspicuity, geometric distortion and distinction of anatomical structures. The signal-to-noise ratio (SNR), lesion contrast, contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) were also measured. Comparisons of the quantitative and qualitative parameters between the two sequences were performed using the paired t-test and the Wilcoxon signed rank test. RESULTS: The scores of overall image quality, lesion conspicuity, geometric distortion and distinction of anatomical structures of rs-EPI were all significantly higher than those of ss-EPI (all p<0.05). The SNR and CNR were higher in rs-EPI than those in ss-EPI (all p<0.05). There was no significant difference between ss-EPI and rs-EPI with regard to ROI size and mean ADCs of the tumour (p=0.574 and p=0.479, respectively), but the mean ADC of the normal tissue was higher in rs-EPI than in ss-EPI (1.73±0.30×10(-3)mm(2)/s vs. 1.60±0.31×10(-3)mm(2)/s, p=0.001). CONCLUSIONS: DW imaging based on readout-segmented echo-planar imaging is a clinically useful technique to improve the image quality for the purpose of evaluating lesions in patients with rectal tumours.

Transthoracic vs transhiatal surgery for cancer of the esophagogastric junction: a meta-analysis.

AIM: To compare the efficacy and safety of the transthoracic and transhiatal approaches for cancer of the esophagogastric junction. METHODS: An electronic and manual search of the literature was conducted in PubMed, EmBase and the Cochrane Library for articles published between March 1998 and January 2013. The pooled data included the following parameters: duration of surgical time, blood loss, dissected lymph nodes, hospital stay time, anastomotic leakage, pulmonary complications, cardiovascular complications, 30-d hospital mortality, and long-term survival. Sensitivity analysis was performed by excluding single studies. RESULTS: Eight studies including 1155 patients with cancer of the esophagogastric junction, with 639 patients in the transthoracic group and 516 in the transhiatal group, were pooled for this study. There were no significant differences between two groups concerning surgical time, blood loss, anastomotic leakage, or cardiovascular complications. Dissected lymph nodes also showed no significant differences between two groups in randomized controlled trials (RCTs) and non-RCTs. However, we did observe a shorter hospital stay (WMD = 1.92, 95%CI: 1.63-2.22, P < 0.00001), lower 30-d hospital mortality (OR = 3.21, 95%CI: 1.13-9.12, P = 0.03), and decreased pulmonary complications (OR = 2.95, 95%CI: 1.95-4.45, P < 0.00001) in the transhiatal group. For overall survival, a potential survival benefit was achieved for type III tumors with the transhiatal approach. CONCLUSION: The transhiatal approach for cancers of the esophagogastric junction, especially types III, should be recommended, and its long-term outcome benefits should be further evaluated.

Is Dor fundoplication optimum after laparoscopic Heller myotomy for achalasia? A meta-analysis.

AIM: To compare the outcome of acid reflux prevention by Dor fundoplication after laparoscopic Heller myotomy (LHM) for achalasia. METHODS: Electronic database PubMed, Ovid (Evidence-Based Medicine Reviews, EmBase and Ovid MEDLINE) and Cochrane Library were searched between January 1995 and September 2012. Bibliographic citation management software (EndNote X3) was used for extracted literature management. Quality assessment of random controlled studies (RCTs) and non-RCTs was performed according to the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0 and a modification of the Newcastle-Ottawa Scale, respectively. The data were analyzed using Review Manager (Version 5.1), and sensitivity analysis was performed by sequentially omitting each study. RESULTS: Finally, 6 studies, including a total of 523 achalasia patients, compared Dor fundoplication with other types of fundoplication after LHM (Dor-other group), and 8 studies, including a total of 528 achalasia patients, compared Dor fundoplication with no fundoplication after LHM (Dor-no group). Dor fundoplication was associated with a significantly higher recurrence rate of clinical regurgitation and pathological acid reflux compared with the other fundoplication group (OR = 7.16, 95%CI: 1.25-40.93, P = 0.03, and OR = 3.79, 95%CI: 1.23-11.72, P = 0.02, respectively). In addition, there were no significant differences between Dor fundoplication and no fundoplication in all subjects. Other outcomes, including complications, dysphagia, postoperative physiologic testing, and operation-related data displayed no significant differences in the two comparison groups. CONCLUSION: Dor fundoplication is not the optimum procedure after LHM for achalasia. We suggest more attention should be paid on quality of life among different fundoplications.

[Transabdominal and transhiatal esophagogastrostomy or esophagojejunostomy using novel double stapling technique].

OBJECTIVE: To explore the techniques of esophagogastrostomy or esophagojejunostomy in the mediastinum through the abdomen and hiatus after extended proximal gastrectomy or total gastrectomy. METHODS: From May 2010 to January 2012, 15 patients with esophagogastric junction carcinoma underwent open transhiatal extended gastrostomy or total gastrectomy. After full mobilization, the anvil was reversely introduced into the esophagus and the esophagus was transected with curved stapler. The rod of the anvil was then pulled out with a stitch to complete esophagogastrostomy after proximal gastrectomy(n=9) or esophagojejunostomy after total gastrectomy(n=6). RESULTS: The anastomosis was successfully performed in all the patients. The mean operation time was(185.5±13.1) min. The mean operation time for anastomosis was(42.0±8.6) min. The mean estimated blood loss was (106.7±34.9) ml. The proximal resection margin was(4.4±1.2) cm. All the margins were negative for residual cancer. There was no postoperative death or fistula. During the follow up, there was one case of anastomotic stenosis which was successfully managed by endoscopic balloon dilatation. CONCLUSIONS: Esophagogastrostomy or esophagojejunostomy can be safely performed with double stapling technique including reverse anvil introduction and curved stapling transection of the esophagus. It is an ideal technique for anastomosis after extended gastrectomy for esophagogastric junction carcinoma.