[System analysis of the ecological distribution of bacteriophages in hospital wastewater]

Phage therapy is one of the most important tools for the treatment of infections with multi-drug resistant bacteria. Such phages are usually isolated from hospital effluents, however, no systematic study on the distribution of phages in hospital effluents has been conducted so far. The aim of this study was to isolate the corresponding phages of common pathogenic bacteria isolated in the clinic as hosts, so as to assess the ecological distribution of phages in hospital wastewater and to provide a reference for the isolation and application of phages of drug-resistant bacteria in the clinic. A cross-sectional study design was used in this study. The 125 pathogenic bacteria (belonging to 16 different strains) isolated from the clinical microbiology laboratory of Qilu Hospital of Shandong University from May to June 2023 were selected as the target strains, and the phages corresponding to these strains were isolated and purified from the hospital wastewater by using the double-layer plate sandwich method. At the same time, the distribution of pathogenic bacteria in the same batch of wastewater was analyzed with the help of mNGS sequencing technology, so as to preliminarily investigate the abundance correspondence between pathogenic bacteria and phages in wastewater. The results showed that a total of 56 phage strains were isolated from 125 clinical pathogens as hosts, corresponding to six pathogens, including Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. All six pathogenic bacteria contained strains with different degrees of drug resistance, with a higher percentage of multi-drug resistant strains in A. baumannii, Escherichia coli and P. aeruginosa. The phage acquisition rates of these six pathogens were, in descending order, Escherichia coli (80%), Stenotrophomonas maltophilia (75%), Pseudomonas aeruginosa (70%), Klebsiella pneumoniae (66.67%), Acinetobacter baumannii (36.36%) and Staphylococcus aureus (12.5%). Preliminary mNGS sequencing results showed that the pathogenic bacteria with higher abundance in the batch of effluent were Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, Acinetobacter baumannii, Klebsiella aerogenes, Klebsiella michiganensis and Pseudomonas aeruginosa. In conclusion, phages of most common clinical Gram-negative pathogens were isolated from hospital wastewater with high isolation rates; however, phages of Gram-positive pathogens were isolated at lower rates, and only phages corresponding to Staphylococcus aureus were isolated in this study. The corresponding mNGS sequencing results showed that the distribution of Gram-negative pathogens in sewage may had a positive correlation with the ecological distribution of phages.

[Comparison of the anorectal function before and after neoadjuvant radiotherapy in mid-low rectal cancer: a retrospective observational study from single center]

Objective: The aim of this study was to evaluate the impact of neoadjuvant radiotherapy on anorectal function of patients with mid-low rectal cancer by means of high-resolution anorectal manometry. Methods: A retrospective observational study was conducted. Information on patients with mid-low rectal cancer was collected from the prospective registry database of Rectal Cancer at Peking Union Medical College Hospital (PUMCH) from June 2020 to April 2023. Anorectal functions were detected using three-dimensional high-resolution manometry system. Logistic regression analysis was performed to identify the factors associated with the changed anorectal manometry. Results: A total of 45 patients with mid-low rectal cancer were included in the study. Thirty-two (71.1%) patients were male, 13 (28.9%) patients were female. The mean age was 60±11 years, and the mean BMI was 23.4±3.7 kg/m2. The mean distance between the lower edge of the tumor and the anal verge was 5.4±1.5 cm. The median size of the tumor was 3.4 (2.9-4.5) cm, and the median circumferential extent of the tumor was 66.0 (45.5-75.0) %. 41 (81.1%) patients were MRI T3-4 and 40 (88.9%) patients were MRI N positive. The resting pressure has a decreasing trend after neoadjuvant radiotherapy (55.3±32.0 mmHg vs. 48.0±28.5 mmHg, t=1.930, P=0.060). There was no significant change in maximum squeezing and the length of the high-pressure zone after neoadjuvant radiotherapy. All volumes describing rectal sensitivity (first sensation, desire to defecate, and maximum tolerance) were lower after neoadjuvant radiotherapy. And maximum tolerance was significantly lower (66.0 [49.0,88.0] ml vs. 52.0 [39.0,73.5] ml, Z=-2.481,P=0.013). Univariate analysis demonstrated that the downstage of N-stage was associated with the decrease in maximum tolerance (OR=6.533, 95%CI:1.254-34.051, P=0.026). Conclusion: Neoadjuvant radiotherapy damages anorectal function by decreasing the resting pressure and rectal sensory threshold of patients. The N-stage downstaging was associated with a decrease in maximum tolerance.

[Application and funding status of oral and craniofacial sciences research projects funded by National Natural Science Foundation of China from 2010 to 2021]

Objective: Based on the application and funding status of National Natural Science Foundation of China (NSFC) in the field of oral and craniofacial sciences (H15), we analyzed the current status of basic research of the Oral and Craniofacial Sciences (OCS) in China, and provided the references for the sustainable and efficient funding of basic research and scientific frontier exploration in the field, supporting the construction of talents and teams, and enhancing the development of OCS in China. Methods: The data of both applied and funded grants of H15 in NSFC from 2010 to 2021 were analyzed, including the number of applications and funding, the amount of funding, the funding rate, the research direction and the supporting units. The status of basic research of H15 was summarized. Results: From 2010 to 2021, H15 received 15 060 applications and funded 2 569 grants. The overall funding rate of H15 was 17.06%, and the total funding amount was 1 140.305 million yuan. The applications and funded projects of H15 were mainly focused on the General Projects and Youth Science Fund Projects, accounting for 90.33% (13 604/15 060) and 88.71% (2 279/2 569) of the total number of applications and funded projects, and 78.05% (89 002.5/114 030.5) of the total funding amount. In terms of talent training, the National Science Foundation for Distinguished Young Scholars received 65 applications, and 6 were founded, with a funding rate of 9.23%. The National Science Foundation for Outstanding Young Scholars received 85 applications, and 13 were founded, with a funding rate of 15.29%. In recent years, the number of applications has gradually increased and the number of grants has remained relatively stable. Among the nine sub-categories of H15, the top three in terms of the number of applications and grants were H1502, H1504, and H1507. H1502 (repair and regeneration of oral and craniofacial tissue and organ defects) received 2 760 applications, and 510 were funded. H1504 (periodontal and oral mucosal diseases) received 2 475 applications, and 419 were funded. H1507 (restoration of tooth defects and loss, and correction of dental deformities) received 2 270 applications, and 367 were funded. Peking University and Sichuan University ranked first and second with 1 092 and 1 001 applications, respectively. The top five recipients were Sichuan University (327 items), Peking University (260 items), Wuhan University (204 items), Shanghai Jiao Tong University (198 items) and the Fourth Military Medical University of the People's Liberation Army (193 items). The funding rates were 32.67%, 23.81%, 23.02%, 21.69% and 29.11%, respectively. Conclusions: Under the support of NSFC, the basic research of oral and craniofacial sciences has been developed in an all-round way. In recent years, the talent training of all echelons has increased year by year, the research direction and geographical coverage is comprehensive, and project support organization has its own research focus and discipline advantages, making contributions to the realization of the goal of healthy China and the progress of world medicine.

[A control study of steroid withdrawal protection strategy after kidney transplantation in children]

Objective: To study the influence of steroid withdrawal protection strategy on height growth in pediatric patients after kidney transplantation. Methods: The prospective cohort study enrolled 40 stage 5 chronic kidney disease children receiving kidney transplantation from July 2017 to September 2022 at Guangzhou Women and Children's Medical Center. Based on the primary preoperative disease, patients with immune abnormality-associated glomerular diseases or unknown causes were assigned to the steroid maintenance group, in which patients received steroid tapering within 3 months after surgery to a maintenance dose of 2.5 to 5.0 mg/d. While patients with hereditary kidney disease or congenital urinary malformations were assigned to the steroid withdrawal group, in which patients had steroids tapered off within 3 months. The characteristics of height catch-up growth and clinical data were compared between the 2 groups at baseline, 6, 12, 18 and 24 months after kidney transplantation. T-test, repeated measurement of variance analysis, Mann-Whitney U test, and Fisher exact test were used for the comparison between the 2 groups. Results: Among the 40 children, 17 were males, 23 were females, 25 were in the steroid withdraw group ((7.8±2.8) years old when receiving kidney transplantation) and 15 cases were in the steroid maintenance group ((7.6±3.5) years old when receiving kidney transplantation). The study population was followed up for (26±12) months. The total dose per unit body weight of steroids in the steroid withdrawal group was lower than that in the steroid maintenance group ((0.13±0.06) vs. (0.36±0.19) mg/(kg·d), t=5.83, P<0.001). The height catch-up rate (ΔHtSDS) in the first year after kidney transplantation in the steroid withdraw and steroid maintenance groups was 1.0 (0.7, 1.4) and 0.4 (0.1, 1.0), respectively; in the second year, the ΔHtSDS in the steroid withdraw group was significantly higher than that in the steroid maintenance group (1.1 (0.2, 1.7) vs. 0.3 (0, 0.8), U=28.00, P=0.039). The HtSDS in the steroid withdrawal group at the five follow-up time points was -2.5±0.8, -2.0±0.8, -1.5±0.8, -1.3±0.9 and -0.5±0.3, respectively, while in the steroid maintenance was -2.4±1.3, -2.2±1.1, -2.0±1.0, -1.8±1.0 and -1.6±1.0, respectively. There were statistically significant differences in HtSDS at different follow-up time points in both 2 groups (F=19.81, P<0.01), but no statistical differences in overall impact between the 2 groups (F=1.13, P=0.204). The steroid treatment was interaction with the increase of follow-up time (F=3.62, P=0.009). At the 24th month after transplantation, the HtSDS in the steroid withdrawal group was significantly higher than that in the steroid maintenance group (P=0.047). Six patients in the steroid withdrawal group experienced antibody-mediated immune rejection (AMR), while 3 did in the steroid maintenance group. Moreover, there was no significant difference in AMR between the two groups (χ2=0.06, P=0.814). Conclusion: The steroid withdrawal protection strategy favors the height catch-up growth in pediatric patients after kidney transplantation and does not increase the risk of postoperative antibody-mediated immune rejection.

[Development and validation of a prognostic prediction model for patients with stage Ⅰ to Ⅲ colon cancer incorporating high-risk pathological features]

Objective: To examine a predictive model that incorporating high risk pathological factors for the prognosis of stage Ⅰ to Ⅲ colon cancer. Methods: This study retrospectively collected clinicopathological information and survival outcomes of stage Ⅰ~Ⅲ colon cancer patients who underwent curative surgery in 7 tertiary hospitals in China from January 1, 2016 to December 31, 2017. A total of 1 650 patients were enrolled, aged (M(IQR)) 62 (18) years (range: 14 to 100). There were 963 males and 687 females. The median follow-up period was 51 months. The Cox proportional hazardous regression model was utilized to select high-risk pathological factors, establish the nomogram and scoring system. The Bootstrap resampling method was utilized for internal validation of the model, the concordance index (C-index) was used to assess discrimination and calibration curves were presented to assess model calibration. The Kaplan-Meier method was used to plot survival curves after risk grouping, and Cox regression was used to compare disease-free survival between subgroups. Results: Age (HR=1.020, 95%CI: 1.008 to 1.033, P=0.001), T stage (T3:HR=1.995,95%CI:1.062 to 3.750,P=0.032;T4:HR=4.196, 95%CI: 2.188 to 8.045, P<0.01), N stage (N1: HR=1.834, 95%CI: 1.307 to 2.574, P<0.01; N2: HR=3.970, 95%CI: 2.724 to 5.787, P<0.01) and number of lymph nodes examined (≥36: HR=0.438, 95%CI: 0.242 to 0.790, P=0.006) were independently associated with disease-free survival. The C-index of the scoring model (model 1) based on age, T stage, N stage, and dichotomous variables of the lymph nodes examined (<12 and ≥12) was 0.723, and the C-index of the scoring model (model 2) based on age, T stage, N stage, and multi-categorical variables of the lymph nodes examined (<12, 12 to <24, 24 to <36, and ≥36) was 0.726. A scoring system was established based on age, T stage, N stage, and multi-categorical variables of lymph nodes examined, the 3-year DFS of the low-risk (≤1), middle-risk (2 to 4) and high-risk (≥5) group were 96.3% (n=711), 89.0% (n=626) and 71.4% (n=313), respectively. Statistically significant difference was observed among groups (P<0.01). Conclusions: The number of lymph nodes examined was an independent prognostic factor for disease-free survival after curative surgery in patients with stage Ⅰ to Ⅲ colon cancer. Incorporating the number of lymph nodes examined as a multi-categorical variable into the T and N staging system could improve prognostic predictive validity.

[Analysis of influencing factors and clinical value of anterior peritoneal reflection for patients with rectal cancer]

Objectives: To investigate the factors influencing the height of anterior peritoneal reflection (APR) for patients with rectal cancer, and to analyze the relationship between the APR and the lateral lymph node metastasis. Methods: Clinical data of 432 patients with tumor located within and below APR were retrospectively collected from the rectal cancer database at the Department of General Surgery, Peking Union Medical College Hospital from August 2020 to September 2022. Ninty-eight non-rectal cancer patients were also enrolled as a control group. There were 308 males and 124 females in the tumor group, aged (M(IQR)) 62 (16) years (range: 24 to 85 years) and 53 males and 45 females in the control group, aged 60 (22) years (range: 27 to 87 years). The APR height, pelvis, and tumor-related parameters were measured by MRI. A multifactor linear regression model was established to analyze the dependent correlation factors of APR height. These factors of the two groups were matched by propensity score matching and their APR heights were compared after matching. An ordinal Logistic regression model was established to explore the relationship between APR-related parameters and radiographic lateral lymph node metastasis. Results: The APR height of the tumor group was (98.7±14.4) mm (range: 43.3 to 154.0 mm) and the control group was (95.1±12.7) mm (range: 68.0 to 137.9 mm). Multivariable linear regression revealed that the greater the weight (B=0.519, 95%CI: 0.399 to 0.640, P<0.01), the anterior pelvic depth (B=0.109, 95%CI: 0.005 to 0.213, P=0.039) and the smaller the bi-ischial diameter (B=-0.172, 95%CI:-0.294 to -0.049, P=0.006), the higher the APR height. The tumor group had a higher APR height than the control group after propensity score matching ((98.3±14.2) mm vs. (95.1±12.7) mm, t=-1.992, P=0.047). Ordinal Logistic regression indicated that the longer segment of the tumor invade the nonperitoneal rectum was an independent influencing factor of radiographic lateral lymph node metastasis (OR=1.016, 95%CI: 1.002 to 1.030, P=0.021), while the distance between the anal verge and the tumor was not (OR=0.986, 95%CI: 0.972 to 1.000, P=0.058). Conclusions: The higher the weight, the deeper and narrower the pelvis, the higher the APR height. There is a certain relationship between APR and lateral lymph node metastasis on imaging.

[Efficacy and safety of ultra rapid lispro in the treatment of type 2 diabetes mellitus: a randomized controlled clinical trial]

Objective: To evaluate and compare the efficacy and safety of ultra-rapid lispro insulin (URLi) and humalog lispro (HL) in the treatment of type 2 diabetes mellitus. Methods: This was an international multicenter, double-blind, randomized controlled study. From May 2019 to January 2021, a total of 481 patients with type 2 diabetes mellitus, who had been using insulin for at least 90 days and had poor glycemic control, were included. These patients were recruited from 34 research centers in China, including Shanghai Jiao Tong University School of Medicine Affiliated Sixth People's Hospital. They were assigned to either the URLi group (319 patients) or the HL group (162 patients) using stratified blocked randomization. The primary endpoint was the change in hemoglobin A1c (HbA1c) relative to baseline after 26 weeks of treatment. Secondary endpoints included the proportion of patients who achieved HbA1c<7.0% and ≤6.5% after 26 weeks of treatment, 1-h postprandial glucose (1hPG) or 2-h postprandial glucose (2hPG) excursions during a mixed meal tolerance test at week 26, as well as safety parameters. Continuous variables were compared using mixed model repeated measures or analysis of covariance, and categorical variables were compared using logistic regression or Fisher's exact test. Results: Data based on the Chinese subgroup showed that there were no statistically significant differences between the URLi and HL groups in terms of male percentage [56.1% (179/319) vs. 56.2% (91/162); P=0.990], age [(59.5±8.4) vs. (59.6±9.3) years; P=0.839] and other baseline characteristics. Regarding the change in HbA1c relative to baseline, the URLi group was non-inferior to the HL group (-0.59%±0.05% vs. -0.66%±0.06%; P=0.312). There were no statistically significant differences between the URLi and HL groups in proportion of patients who achieved HbA1c<7.0% [47.3% (138/292) vs. 45.2% (70/155); P=0.907] and≤6.5% [27.7% (81/292) vs. 27.7% (43/155); P=0.816]. The excursions in 1hPG [(6.20±0.21) vs. (6.90±0.25) mmol/L; P=0.001] and 2hPG [(8.10±0.27) vs. (9.30±0.31) mmol/L; P<0.001] were lower in the URLi group than the HL group, with statistically significant differences. In terms of safety, there were no statistically significant differences in the percentage of subjects who reported treatment-emergent adverse events between the URLi and HL groups [49.8% (159/319) vs. 50.0% (81/162); P=1.000]. The event rate of nocturnal hypoglycemia was lower in the URLi group than the HL group, with statistically significant differences [(0.53±0.10) vs. (0.89±0.16) events per patient-year; P=0.040]. Conclusions: With good glycemic control, URLi showed non-inferiority for HbA1c improvement versus HL and was superior to HL for postprandial glucose excursion control. Meanwhile the rate and incidence of nocturnal hypoglycemia were lower in the URLi group than the HL group.

[Safety and feasibility of right colectomy via a transvaginal approach: early experience from a single center]

Objective: To investigate the safety and feasibility of performing right colectomy via a transvaginal approach. Methods: This was a retrospeltive cohort study. Data of 30 patients who had undergone transvaginal laparoscopic right colectomy (transvaginal group) and 23 women who had undergone laparoscopic right colectomy (laparoscopic group) from January 2019 to March 2022 in the Division of Colorectal Surgery, Department of General Surgery, Peking Union Medical College Hospital were collected retrospectively. The inclusion criteria for the transvaginal group were as follows: (1) post-menopausal woman; (2) transverse diameter of the tumor < 6 cm; and (3) diagnosis of benign polyps that were unresectable by endoscopy, mucinous tumors of the appendix, or confirmed right colon cancer not requiring D3 lymphadenectomy. The inclusion criteria for the laparoscopic group were as follows: (1) pathologically confirmed adenocarcinoma or high-grade intraepithelial neoplasia; (2) lesion located from the cecum to the right third of the transverse colon; and (3) clinically stage T1-4NanyM0. The exclusion criteria for the laparoscopic group were as follows: (1) distant metastasis discovered during surgical exploration; (2) multiple organ resection required or R0 resection not possible; or (3) conversion to open surgery required. Safety was evaluated on the basis of intra- and post-operative complications. Feasibility was assessed by postoperative recovery and quality of operative specimen. The body mass index was lower in the transvaginal than the laparoscopic group (22.0±3.1 kg/m2 vs. 24.1±2.6 kg/m2, t=2.617, P=0.012). Results: Among the 30 transvaginal laparoscopic right colectomies, 26 were pure transvaginal surgeries, three required laparoscopic assistance because of difficulties with anastomosis (n=2) or abdominal adhesions (n=1), and one required conversion to laparoscopic surgery because of vascular injury. Compared with the laparoscopic group, the transvaginal group had a longer surgery time (175.0 [147.5, 216.3] minutes vs. 120.0 [100.0, 120.0] minutes, U=63.000, P<0.001) and more blood loss (30.0 [10.0, 50.0] ml vs. 23.0 [10.0, 20.0] ml, U=208.000, P=0.011). The incidence of intraoperative complications (16.7% [5/30) vs. 0, P=0.061] was comparable between the two groups. In the transvaginal group, the sites of intraoperative injuries were bladder (n=3), ileocecal artery (n=1), and right uterine artery (n=1). The incidence of postoperative complications (20.0% [6/30] vs. 17.4% [4/23], χ2<0.001,P>0.999) was also comparable between the two groups. Clavien-Dindo grade III postoperative complications occurred in two patients in the transvaginal group (one patient had a pelvic hematoma that required embolization; the other had a vesico-vaginal fistula that required surgery). Postoperative visual analogue scale scores were significantly lower (P<0.001) in the transvaginal group. Times to first flatus, ambulation, and first intake and duration of postoperative hospital stay were comparable between the two groups (P>0.05). The proportion of specimens of moderate quality was 83.3% (25/30) in the transvaginal group and 100% (23/23) in the laparoscopic group; this difference is not significant (P=0.061). Among patients who underwent D2 lymph node dissection, the number of lymph nodes examined was comparable between the transvaginal (n=23) and laparoscopic groups (n=7) (18 [15, 27] vs. 20 [16, 29], U=69.500, P=0.589). Conclusion: Transvaginal right colon surgery is associated with less postoperative pain than laparoscopic surgery, but is not yet the preferred alternative because of the incidence of surgical complications.

Energy transfer across magnetopause under dawn-dusk IMFs

A parametric study on the energy transfer of the solar wind across the magnetopause entering the magnetosphere is conducted using a global magnetohydrodynamic numerical simulation. The characteristics of the mechanical and electromagnetic energy distribution under the dawn-dusk interplanetary magnetic fields (IMFs) are investigated by analyzing magnetic reconnection and viscous effect, and compared with the radial and north-south IMFs. It is shown that (1) the interactions at the magnetopause and the transfer of energy across this boundary move in relation to the IMF orientation. (2) For the duskward IMF, the mechanical energy flow clearly enters the equatorial and low-latitude regions on the dayside, and the electromagnetic energy flow has a small inflow on the equatorial and low latitudes of the dayside. A significant energy inflow appears on the dawn side in the northern hemisphere and the dusk side in the southern hemisphere near the polar cusp. (3) The energy distribution characteristics across the magnetopause under dawn-dusk IMFs are mirror symmetric about the [Formula: see text] plane. (4) For a magnetic field of 5 nT, the electromagnetic energy input under the dawn-dusk IMFs is twice as large as the mechanical energy and the electromagnetic energy under the radial IMF, which is five times as large as the electromagnetic energy during the pure northward IMF, but only half as large as the electromagnetic energy under the pure southward IMF. The mechanical energy input under dawn-dusk IMFs has the same magnitude as that under radial and north-south IMFs. The magnitude of the energy transfer rate for the dawn IMF and dusk IMF (about 3.5%) is between 1.71% for the northward IMF and 4.95% for the southward IMF, but higher than 2.22% for the radial IMF. The Akasofu-type energy-coupling formula, [Formula: see text], underestimates the energy input from the solar wind under [Formula: see text] dominated IMF.

[Predictive value of MRI pelvic measurements for "difficult pelvis" during total mesorectal excision]

Objective: Total mesorectal resection (TME) is difficult to perform for rectal cancer patients with anatomical confines of the pelvis or thick mesorectal fat. This study aimed to evaluate the ability of pelvic dimensions to predict the difficulty of TME, and establish a nomogram for predicting its difficulty. Methods: The inclusion criteria for this retrospective study were as follows: (1) tumor within 15 cm of the anal verge; (2) rectal cancer confirmed by preoperative pathological examination; (3) adequate preoperative MRI data; (4) depth of tumor invasion T1-4a; and (5) grade of surgical difficulty available. Patients who had undergone non-TME surgery were excluded. A total of 88 patients with rectal cancer who underwent TME between March 2019 and November 2021 were eligible for this study. The system for scaling difficulty was as follows: Grade I, easy procedure, no difficulties; Grade II, difficult procedure, but no impact on specimen quality (complete TME); Grade III, difficult procedure, with a slight impact on specimen quality (near-complete TME); Grade IV: very difficult procedure, with remarkable impact on specimen quality (incomplete TME). We classified Grades I-II as no surgical difficulty and grades III-IV as surgical difficulty. Pelvic parameters included pelvic inlet length, anteroposterior length of the mid-pelvis, pelvic outlet length, pubic tubercle height, sacral length, sacral depth, distance from the pubis to the pelvic floor, anterior pelvic depth, interspinous distance, and inter-tuberosity distance. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with the difficulty of TME, and a nomogram predicting the difficulty of the procedure was established. Results: The study cohort comprised 88 patients, 30 (34.1%) of whom were classified as having undergone difficult procedures and 58 (65.9%) non-difficult procedures. The median age was 64 years (56-70), 51 patients were male and 64 received neoadjuvant therapy. The median pelvic inlet length, anteroposterior length of the mid-pelvis, pelvic outlet length, pubic tubercle height, sacral length, sacral depth, distance from the pubis to the pelvic floor, anterior pelvic depth, interspinous distance, and inter-tuberosity distance were 12.0 cm, 11.0 cm, 8.6 cm, 4.9 cm, 12.6 cm, 3.7 cm, 3.0 cm, 13.3 cm, 10.2 cm, and 12.2 cm, respectively. Multivariable analyses showed that preoperative chemoradiotherapy (OR=4.97,95% CI: 1.25-19.71, P=0.023), distance between the tumor and the anal verge (OR=1.31, 95% CI: 1.02-1.67, P=0.035) and pubic tubercle height (OR=3.36, 95% CI: 1.56-7.25, P=0.002) were associated with surgical difficulty. We then built and validated a predictive nomogram based on the above three variables (AUC = 0.795, 95%CI: 0.696-0.895). Conclusion: Our research demonstrated that our system for scaling surgical difficulty of TME is useful and practical. Preoperative chemoradiotherapy, distance between tumor and anal verge, and pubic tubercle height are risk factors for surgical difficulty. These data may aid surgeons in planning appropriate surgical procedures.

[Analysis of prognosis factors of postoperative cardiac complications in colorectal cancer patients with comorbid coronary artery disease]

Objective: To examine the prognosis factors of postoperative cardiac complications in colorectal cancer patients co-morbidated with coronary artery disease. Methods: Clinical data of 449 patients colorectal cancer patients co-morbidated with coronary artery disease accepted redical surgery from April 2013 to April 2020 at Department of General Surgery, Peking Union Medical College Hospital were analyzed retrospectively. There were 306 males and 143 females, aging (68.7±8.9) years (range: 44 to 89 years). Postoperative acute coronary syndrome, new-onset arrhythmia and heart failure that causes clinical symptoms were recorded as cardiac complications. t test, χ2 test and Fisher exact test were used for univariate analysis of prognosis factors of postoperative cardiac events. The variables with P<0.05 were included in the multivariate Logistic regression was used to determine the independent prognosis factors. Results: After surgery, 44 patients (9.8%) suffered from at least one cardiac event, including 30 patients with acute coronary syndrome, 19 patients with new-onset arrhythmia and 9 patients with heart failure. There were 3 deaths in the cohort within 30 days after surgery. Two patients died from cardiac-related complications, and one from septic shock due to postoperative anastomotic leaks. On Univariate analysis showed that cardiac complications were associated with age ≥80 years, co-morbidated diabetes, emergency surgery, re-operation, anastomotic leakage, intestinal flora disorder and elevation of preoperative neutrophil-lymphocyte ratio (χ2: 4.308 to 12.219, all P<0.05). Multivariate Logistic regression analysis identified age ≥80 years(OR=3.195, 95%CI: 1.379 to 7.407, P=0.007), co-morbidated diabetes (OR=2.551, 95%CI: 1.294 to 5.025, P=0.007), emergency surgery (OR=4.717, 95%CI: 1.052 to 20.833, P=0.043), and elevated preoperative neutrophil-lymphocyte ratio (OR=1.114, 95%CI: 1.018 to 1.218, P=0.018) as independent prognosis factors for cardiac complications. Conclusions: Emergency surgery, advanced age, co-morbidated type 2 diabetes and elevated preoperative neutrophil-lymphocyte ratio may increase the risk of postoperative cardiac complications in colorectal cancer patients with coronary artery disease. Surgeons should strictly master surgical indications, pay attention to preoperative assessment, perioperative monitoring, and diagnosis and treatment of postoperative complications in order to reduce the risk of complications.

[Safety and prognosis analysis of transanal total mesorectal excision versus laparoscopic mesorectal excision for mid-low rectal cancer]

Objective: To compare the short-term and long-term outcomes between transanal total mesorectal excision (taTME) and laparoscopic total mesorectal excision (laTME) for mid-to-low rectal cancer and to evaluate the learning curve of taTME. Methods: This study was a retrospective cohort study. Firstly, consecutive patients undergoing total mesorectal excision who were registered in the prospective established database of Division of Colorectal Diseases, Department of General Surgery, Peking Union Medical College Hospital during July 2014 to June 2020 were recruited. The enrolled patients were divided into taTME and laTME group. The demographic data, clinical characteristics, neoadjuvant treatment, intraoperative and postoperative complications, pathological results and follow-up data were extracted from the database. The primary endpoint was the incidence of anastomotic leakage and the secondary endpoints included the 3-year disease-free survival (DFS) and the 3-year local recurrence rate. Independent t-test for comparison between groups of normally distributed measures; skewed measures were expressed as M (range). Categorical variables were expressed as examples (%) and the χ(2) or Fisher exact probability was used for comparison between groups. When comparing the incidence of anastomotic leakage, 5 variables including sex, BMI, clinical stage evaluated by MRI, distance from tumor to anal margin evaluated by MRI, and whether receiving neoadjuvant treatment were balanced by propensity score matching (PSM) to adjust confounders. Kaplan-Meier curve and Log-rank test were used to compare the DFS of two groups. Cox proportional hazard model was used to analyze and determine the independent risk factors affecting the DFS of patients with mid-low rectal cancer. Secondly, the data of consecutive patients undergoing taTME performed by the same surgical team (the trananal procedures were performed by the same main surgeon) from February 2017 to March 2021 were separately extracted and analyzed. The multidimensional cumulative sum (CUSUM) control chart was used to draw the learning curve of taTME. The outcomes of 'mature' taTME cases through learning curve were compared with laTME cases and the independent risk factors of DFS of 'mature' cases were also analyzed. Results: Two hundred and forty-three patients were eventually enrolled, including 182 undergoing laTME and 61 undergoing taTME. After PSM, both fifty-two patients were in laTME group and taTME group respectively, and patients of these two groups had comparable characteristics in sex, age, BMI, clinical tumor stage, distance from tumor to anal margin by MRI, mesorectal fasciae (MRF) and extramural vascular invasion (EMVI) by MRI and proportion of receiving neoadjuvant treatment. After PSM, as compared to laTME group, taTME group showed significantly longer operation time [(198.4±58.3) min vs. (147.9±47.3) min, t=-4.321, P<0.001], higher ratio of blood loss >100 ml during surgery [17.3% (9/52) vs. 0, P=0.003], higher incidence of anastomotic leakage [26.9% (14/52) vs. 3.8% (2/52), χ(2)=10.636, P=0.001] and higher morbidity of overall postoperative complications [55.8%(29/52) vs. 19.2% (10/52), χ(2)=14.810, P<0.001]. Total harvested lymph nodes and circumferential resection margin involvement were comparable between two groups (both P>0.05). The median follow-up for the whole group was 24 (1 to 72) months, with 4 cases lost, giving a follow-up rate of 98.4% (239/243). The laTME group had significantly better 3-year DFS than taTME group (83.9% vs. 73.0%, P=0.019), while the 3-year local recurrence rate was similar in two groups (1.7% vs. 3.6%, P=0.420). Multivariate analysis showed that and taTME surgery (HR=3.202, 95%CI: 1.592-6.441, P=0.001) the postoperative pathological staging of UICC stage II (HR=13.862, 95%CI:1.810-106.150, P=0.011), stage III (HR=8.705, 95%CI: 1.104-68.670, P=0.040) were independent risk factors for 3-year DFS. Analysis of taTME learning curve revealed that surgeons would cross over the learning stage after performing 28 cases. To compare the two groups excluding the cases within the learning stage, there was no significant difference between two groups after PSM no matter in the incidence of anastomotic leakage [taTME: 6.7%(1/15); laTME: 5.3% (2/38), P=1.000] or overall complications [taTME: 33.3%(5/15), laTME: 26.3%(10/38), P=0.737]. The taTME was still an independent risk factor of 3-year DFS only analyzing patients crossing over the learning stage (HR=5.351, 95%CI:1.666-17.192, P=0.005), and whether crossing over the learning stage was not the independent risk factor of 3-year DFS for mid-low rectal cancer patients undergoing taTME (HR=0.954, 95%CI:0.227-4.017, P=0.949). Conclusions: Compared with conventional laTME, taTME may increase the risk of anastomotic leakage and compromise the oncological outcomes. Performing taTME within the learning stage may significantly increase the risk of postoperative anastomotic leakage.

[Efficacy and safety of total neoadjuvant therapy versus neoadjuvant chemoradiotherapy in the treatment of locally advanced rectal cancer: a meta-analysis]

Objective: To systematically evaluate the efficacy and safety of total neoadjuvant therapy (TNT) in the comprehensive treatment of locally advanced rectal cancer. Methods: Literatures were screened from PubMed, Embase, Web of Science, Cochrane Library, CBM, Wanfang Data, VIP and CNKI from the inception date to May 2021 to collect the randomized controlled clinical trials (RCTs) of TNT followed by total mesorectal excision (TME) versus neoadjuvant chemotherapy (nCRT) followed by TME in the treatment of locally advanced rectal cancer. The data of overall survival, disease-free survival, R0 radical resection rate, pathological complete response (pCR) rate, T downstaging rate, the incidence of adverse events ≥ grade III, including neutropenia, nausea and vomiting, diarrhea, radiation dermatitis and nervous system toxicity, and the morbidity of complications within postoperative 30 days of the two groups were extracted from the included literatures. Review Manager 5.3 software was utilized for statistical meta-analysis. Results: Nine RCTs were finally enrolled including 2430 patients. Meta-analysis results showed that compared with nCRT group, patients in TNT group had longer overall survival (HR=0.80, 95%CI: 0.65-0.97, P=0.03) and higher pCR rate (RR=1.73, 95%CI: 1.44-2.08, P<0.01) with significant differences. Besides, there were no significant differences between two groups in disease-free survival (HR=0.86, 95%CI:0.71-1.05, P=0.14), R0 radical resection rate (RR=1.02, 95%CI: 0.99-1.06, P=0.17) and T downstaging rate (RR=1.04, 95%CI: 0.89-1.22, P=0.58) between two groups. In terms of treatment safety, the incidence of adverse events ≥ grade III (RR=1.09, 95%CI: 0.70-1.70, P=0.70) and morbidity of complications within postoperative 30 days (RR=1.07, 95%CI: 0.97-1.18, P=0.19) did not significantly differ between two groups. Conclusions: In the treatment of locally advanced rectal cancer, TNT may bring more survival benefits than nCRT and does not increase the incidence of adverse events and postoperative complications. Therefore, TNT could be used as a recommended treatment for patients with locally advanced rectal cancer.

[Risk factors of postoperative surgical site infection in colon cancer based on a single center database]

Objective: To explore the incidence and risk factors of postoperative surgical site infection (SSI) after colon cancer surgery. Methods: A retrospective case-control study was performed. Patients diagnosed with colon cancer who underwent radical surgery between January 2016 and May 2021 were included, and demographic characteristics, comorbidities, laboratory tests, surgical data and postoperative complications were extracted from the specialized prospective database at Department of General Surgery, Peking Union Medical College Hospital. Case exclusion criteria: (1) simultaneously multiple primary colon cancer; (2) segmental resection, subtotal colectomy, or total colectomy; (3) patients undergoing colostomy/ileostomy during the operation or in the state of colostomy/ileostomy before the operation; (4) patients receiving natural orifice specimen extraction surgery or transvaginal colon surgery; (5) patients with the history of colectomy; (6) emergency operation due to intestinal obstruction, perforation and acute bleeding; (7) intestinal diversion operation; (8) benign lesions confirmed by postoperative pathology; (9) patients not following the colorectal clinical pathway of our department for intestinal preparation and antibiotic application. Univariate analysis and multivariate analysis were used to determine the risk factors of SSI after colon cancer surgery. Results: A total of 1291 patients were enrolled in the study. 94.3% (1217/1291) of cases received laparoscopic surgery. The incidence of overall SSI was 5.3% (69/1291). According to tumor location, the incidence of SSI in the right colon, transverse colon, left colon and sigmoid colon was 8.6% (40/465), 5.2% (11/213), 7.1% (7/98) and 2.1% (11/515) respectively. According to resection range, the incidence of SSI after right hemicolectomy, transverse colectomy, left hemicolectomy and sigmoid colectomy was 8.2% (48/588), 4.5% (2/44), 4.8% (8 /167) and 2.2% (11/492) respectively. Univariate analysis showed that preoperative BUN≥7.14 mmol/L, tumor site, resection range, intestinal anastomotic approach, postoperative diarrhea, anastomotic leakage, postoperative pneumonia, and anastomotic technique were related to SSI (all P<0.05). Multivariate analysis revealed that anastomotic leakage (OR=22.074, 95%CI: 6.172-78.953, P<0.001), pneumonia (OR=4.100, 95%CI: 1.546-10.869, P=0.005), intracorporeal anastomosis (OR=5.288, 95%CI: 2.919-9.577,P<0.001) were independent risk factors of SSI. Subgroup analysis showed that in right hemicolectomy, the incidence of SSI in intracorporeal anastomosis was 19.8% (32/162), which was significantly higher than that in extracorporeal anastomosis (3.8%, 16/426, χ(2)=40.064, P<0.001). In transverse colectomy [5.0% (2/40) vs. 0, χ(2)=0.210, P=1.000], left hemicolectomy [5.4% (8/148) vs. 0, χ(2)=1.079, P=0.599] and sigmoid colectomy [2.1% (10/482) vs. 10.0% (1/10), χ(2)=2.815, P=0.204], no significant differences of SSI incidence were found between intracorporeal anastomosis and extracorporeal anastomosis (all P>0.05). Conclusions: The incidence of SSI increases with the resection range from sigmoid colectomy to right hemicolectomy. Intracorporeal anastomosis and postoperative anastomotic leakage are independent risk factors of SSI. Attentions should be paid to the possibility of postoperative pneumonia and actively effective treatment measures should be carried out.

[Antibiotic resistance and virulence characteristics analysis of a carbapenem-resistant hypervirulent Klebsiella pneumoniae]

Objective: To characterize the antibiotic resistance and virulence in a carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods: A CRKP (designated K. pneumoniae C35) was isolated from a stool sample. The minimal inhibitory concentrations of antimicrobial agents were determined using the broth microdilution method. Whole-genome sequencing and genome analysis were performed to identify the antibiotic resistance and virulence genes. The genetic relationship among K. pneumoniae C35 and other CRKP isolates from our hospital was analyzed by single nucleotide polymorphism (SNP) typing of core genomes. Conjugation experiments were carried out by filter mating to evaluate the transferability and efficiency of resistance genes. The virulence phenotype was determined by Galleria mellonella infection model. Results: K. pneumoniae C35 exhibited resistance to the majority of tested antibiotics, especially carbapenems, sulbactam, and polymyxins. SNP typing showed that K. pneumoniae C35 shared a high degree of sequence homology with several CRKP isolates from different wards. This ST11 CRKP carried 13 resistance genes, including bla_KPC-2, bla_CTX-M-199, mcr-1, and tet(A) variant. bla_KPC-2 gene was located on an IncFⅡ plasmid with>69 800 bp in size, bla_CTX-M-199 and mcr-1 genes were located on an IncI2 plasmid (>64 800 bp), and tet(A) variant was located on an unknown Inc-type plasmid (83 628bp). All these three plasmids were conjugative. K. pneumoniae C35 was found to harbor rmpA, rmpA2, and iucABCD aerobactin-related genes, and was considered to be classic carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP). The virulence potential of this strain was confirmed in a Galleria mellonella infection model. The survival rate of the larvae injected with strain C35 at 48 h after infection was significantly lower than that of negative control strain (16.7% vs 80.0%). Conclusion: Multiple conjugative plasmids are identified in a faecal CR-hvKP. The IncI2 plasmid co-carrying both bla_CTX-M-199 and mcr-1 genes is firstly identified in CR-hvKP. The emergence of such strain should be alerted and active surveillance is warranted.

[Molecular-related epidemic characteristics of influenza A (H3N2) viruses in Guangzhou, 2019]

Objective: To isolate the influenza A (H3N2) viruses from different sources in Guangzhou in 2019 and analyze these viruses' evolution and variation characteristics. Methods: The hemagglutinin (HA) and neuraminidase (NA) genes of H3N2 isolates from outpatient monitoring, influenza outbreaks, and inpatient severe cases in Guangzhou in 2019 were sequenced. Bioinformatics software analyzed the variations and evolution characteristics of HA and NA genes. Results: The epidemic peaks of influenza A (H3N2) viruses were made up of period Ⅰ (from January to August) and period Ⅱ (from November to December). The positive rate of influenza A (H3N2) in males was 13.46% (703/5 221), which was higher than that in females (11.50%, 510/4 435) (χ²=8.43,P=0.00). The group's positive rate of 10-20 years old was the highest (25.18%,665/2 641). The isolates from different sources were highly homologous and closely related to 3C.2a.1 branches, which could be further divided into three small groups of Group 1-3. Gene recombination was observed between different branches. The mutations of HA antigen sites gradually appeared from Group 1 to Group 3, leading to new antigen drift. Variations of HA antigenic sites mainly occurred in the region of A and B. The mutations of receptor binding sites of Group 1 and Group 3 viruses occurred in the anterior and posterior walls. There were two glycosylation sites lacked on region A of HA antigen observed in the isolates of Group 2-3. Conclusions: Genetic variations of H3N2 influenza viruses in Guangzhou included gene mutations and gene recombination. Under the pressure of the vaccine, the evolution of viruses was rapid. Therefore, the monitoring of molecular-related epidemic characteristics of the H3N2 influenza virus was necessary.

[Clinicopathological characteristics, diagnosis, and treatment of 29 cases of signet ring cell carcinoma of the rectum and sigmoid colon]

Objective: To investigate the clinicopathological characteristics and the therapeutic effects of signet ring cell carcinoma (SRCC) of rectum and sigmoid colon. Methods: Clinical data and the follow-up information of 29 SRCC patients treated in our tertiary care center from 2008 to 2018 were retrospectively reviewed. The clinicopathological features, diagnostic and therapeutic effects, and the prognostic outcomes were analyzed. Results: Among the 29 patients, 17 were male, 12 were female. The average age was (48.7±14.3) years. Colonoscopy revealed the features of diffuse circumferential thickening of the bowel wall in 20/29 cases (69.0%), while in 9/29 cases (31.0%), endoscopic biopsies showed false negative results. Twenty-five% (4/16) and 17.6% (3/17) lesions were misdiagnosed as the inflammatory changes by endoscopic rectal ultrasonography exam and rectal MRI scan, respectively. Thirteen of the 29 patients received the neoadjuvant chemoradiotherapy (NCRT), 27 patients underwent the radical resection surgeries, and 8 underwent the postoperative radiotherapy. With a median follow-up of 38.5 (3.5-87.0) months, the cumulative 3-years overall survival (OS) rate was 54.0%, and the cumulative 3-years disease-free survival (DFS) rate was 43.0%. The OS rates of patients treated with or without NCRT (non-NCRT) were 46.2% and 69.2%, respectively, without significant difference (P>0.05). The DFS rates of patients treated with or without NCRT were 45.8% and 39.2%, respectively, without significant difference (P>0.05). Parameters including age younger than 40 years and tumor size larger than 5 cm were independent potential risk factors for shortened OS (P<0.05). Conclusions: SRCC of the rectum and sigmoid colon is a rare malignant tumor with special clinical manifestations. It is younger-onset, highly malignant and with very poor prognosis. Therefore, in-depth researches with focus upon the progress of molecular oncology are urgently needed to substantially improve the therapeutic effect of this disease.

[The appropriate cut-off point of time in range (TIR) for evaluating glucose control in type 2 diabetes mellitus]

Objective: To investigate the appropriate cut-off point of time in range (TIR) for evaluating glucose control in type 2 diabetes mellitus (T2DM) patients, and analyze the prevalence of abnormal carotid intima-media thickness (CIMT) and diabetic retinopathy (DR) in different TIR categories. Methods: A total of 2 161 subjects with T2DM (1 183 males) were enrolled from hospitalized patients at the Department of Endocrinology and Metabolism of the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University from January 2005 to February 2012. The age of the enrolled participants was (60.4±11.9) years. Each patient underwent continuous glucose monitoring (CGM) for three consecutive days, then TIR (3.9-10.0 mmol/L), time above range (TAR) and time below range (TBR) were calculated. Fundus photography and carotid artery Doppler ultrasound were performed to diagnose DR and abnormal CIMT (defined as CIMT≥1.0 mm), respectively. Multivariate logistic regression models were used to examine the independent association of different TIR groups with CIMT and DR. Results: All subjects were divided into 4 groups according to TIR:≤40%, 41%-70%, 71%-85% and>85%. Significant linear trends in age, diabetes duration, body mass index (BMI), total cholesterol, glycated hemoglobin A1c (HbA1c), TAR and mean glucose (MG) existed among the 4 groups (all P(trend)<0.05). However, there was only a weak correlation between TIR and TBR (<3.9 mmol/L) (r=0.087, P<0.001), and no significant association was observed between TBR (<3 mmol/L) and the TIR categories (P(trend)=0.378). The overall prevalence of abnormal CIMT and DR was 12.1% and 23.8%, respectively. The prevalence of abnormal CIMT in the 4 groups with ascending levels of TIR was 16.9% (59/349), 12.9% (96/746), 11.2% (57/510) and 9.0% (50/556) (P(trend)<0.001), respectively. And the prevalence of DR was 30.7% (107/349), 29.4% (219/746), 20.8% (106/510) and 14.9% (83/556), respectively (P(trend)<0.001). In the binary logistic regression model by adjusting confounding factors, compared with TIR≤ 40%, the risk of abnormal CIMT was reduced by 33.8% (OR=0.662, 95%CI: 0.456-0.963, P=0.031), 40.8% (OR=0.592, 95%CI: 0.390-0.899, P=0.014), and 45.0% (OR=0.550, 95%CI: 0.358-0.846, P=0.006) in the other three groups, respectively. And the risk of DR was reduced by 2.9% (OR=0.971, 95%CI: 0.725-1.301, P=0.844), 33.4%(OR=0.666, 95%CI: 0.479-0.924, P=0.015) and 53.3% (OR=0.467, 95%CI: 0.331-0.657, P<0.001), respectively. Conclusion: Using 40%, 70% and 85% as cut-off point of TIR helps stratify the risk of diabetic complications, and assess the glucose control (Poor: TIR≤40%; Unsatisfactory: TIR≤70%; Satisfactory: TIR>70%; Optimal: TIR>85%) in patients with T2DM.

[Epidemiological characteristics of a case infected with avian influenza A (H5N6) virus associated with exposure to aerosol]

Objective: To investigate the epidemiological and clinical characteristics of a case infected with avian influenza A (H5N6) virus associated with exposure to aerosol and provide evidence for the prevention and control of human infection with avian influenza virus. Methods: Epidemiological investigation was conducted to identify the history of exposure, infection route, and disease progression. Real-time fluorescent quantitative RT-PCR was used to test the samples collected from the case, close contacts, environment and poultry market. Results: The case had no history of exposure to live poultry and poultry market. But before the onset the case had a history of exposure to the live poultry placed in a car with doors and windows closed. The samples collected from the case's lower respiratory tract and the remaining frozen chicken meat were all influenza A (H5N6) virus positive. Conclusions: The source of infection was the live poultry, and the infection route might be the exposure to aerosol in a car with doors and windows closed, where the poultry were temporarily stored. It is necessary to promote centralized poultry slaughtering, cold chain distribution and fresh poultry sale, as well as strengthen health education and establish the concept of consuming fresh poultry.

[Overlap gastroduodenostomy in totally laparoscopic distal gastrectomy for gastric cancer]

Objective: The aim of the current study is to compare the short-term clinical outcomes between Billroth-I reconstruction using an overlap method and delta-shaped anastomosis in totally laparoscopic distal gastrectomy (TLDG). Method: A retrospective cohort study was performed. The following inclusion criteria were applied: (1) Preoperative gastroscopy and CT confirmed that the tumor is located in the antrum of the stomach, and the biopsy suggested adenocarcinoma; (2) Chest, abdomen and pelvis enhanced CT showed no evidence of distant metastasis; (3) Preoperative gastric reconstruction CT or endoscopic ultrasonography suggested that the clinical stage of the tumor is stage I-III. (4) During the operation, the tumor position was confirmed to be located in the antrum of the stomach by nanocarbon injection or gastroscope; (5) Complete laparoscopic radical gastrectomy for distal gastrectomy, and the gastrointestinal reconstruction was performed by delta-shaped anastomosis or overlap anastomosis. And the following exclusion criteria were applied: (1) History of gastric surgery; (2) Patients who cannot tolerate laparoscopic surgery because of comorbidities. Finally, data on 43 consecutive patients who underwent TLDG with Billroth-I reconstruction between January 2016 and November 2018 in Peking Union Medical College Hospital were retrospectively reviewed. Patients were divided into those who underwent Billroth-I reconstruction using an overlap method (n=20) or using delta-shaped anastomosis (n=23). The demographic and clinical characteristics and perioperative data of the two groups were analyzed. Measurement data that conformed to the normal distribution were expressed as the mean ± s, and differences between groups were compared using Student's t-test; comparisons between the counting data groups were performed using the χ(2) test or the continuously corrected χ(2) test. Results: The demographic and clinical characteristics were similar between the delta-shaped group and the overlap group (P>0.05). There was no significant difference between groups regarding operation time [(185.9±22.8) minutes vs. (184.0±25.8) minutes, t=0.260, P=0.796], blood loss [(50.9±36.0) ml vs. (47.0±30.8) ml, t=0.375, P=0.709], number of stapler reloads used for anastomosis (5.1±0.3 vs. 5.2±0.6, t=-0.465, P=0.651), time to flatus [(3.3±0.9) days vs. (3.6±0.9) days, t=-1.067, P=0.292) and postoperative hospitalization [(8.8±3.1) days vs. (10.4±3.8) days,t=-1.494, P=0.143]. As for the delta-shaped group and the overlap group, the anastomotic leakage rate was 4.3% (1/23) and 0 (χ(2)=0.000, P=1.000), respectively. The incidence of anastomotic bleeding was 4.3% (1/23) and 5.0% (1/20) (χ(2)=0.000, P=1.000), while the incidence of intra-abdominal hemorrhage was 4.3% (1/23) and 0 (χ(2)=0.000, P=1.000). The incidence of gastric emptying disorders was 4.3% (1/23) and 30.0% (6/20), respectively (χ(2)=3.454, P=0.063). All complications were cured after conservative treatment or symptomatic treatment. Conclusion: The overlap method for Billroth-I reconstruction is safe and feasible.

[Exploring of a prognostic long non-coding RNA signature of hepatocellular carcinoma by using public database]

Objective: To explore an effective long non-coding RNA (lncRNA) signature in predicting the prognosis of hepatocellular carcinoma through the analysis on RNA sequencing data of hepatocellular carcinoma patients and peritumoral tissues in the Cancer Genome Atlas (TCGA) database. Methods: The clinical characteristics and RNA sequencing data of 377 hepatocellular carcinoma patients were obtained from TCGA database by the end of February 2018. Then, differentially expressed lncRNAs between 50 pairs of tumor and peritumoral tissues were explored using student's t-test. Next, a lncRNA signature was established through LASSO Cox regression analysis. All the patients were divided into four groups (<P(25), P(25)-, P(50)-, ≥P(75)) based on the cut-off quartiles signature. Finally, compared with the control group (<P(25)), the hazard ratios (HRs) of three groups (P(25)-, P(50)-, ≥P(75)) were calculated by using Cox regression. The survival outcomes of patients in the four groups were compared to evaluate the capacity of the lncRNA signature model. Results: A total of 951 differentially expressed lncRNAs were identified between tumor and peritumoral tissues. A three-lncRNA signature, including LNCSRLR, MKLN1-AS and ZFPM2-AS1, was established to predict the prognosis of hepatocellular carcinoma patients. The outcome suggested that the death risk of the ≥P(75) group was 1.57 times larger than that of the <P(25) group (95%CI: 1.06-2.31, P<0.05). Conclusion: The three-lncRNA signature, which established by LNCSRLR, MKLN1-AS and ZFPM2-AS1, was significantly associated with the prognosis of hepatocellular carcinoma patients based on TCGA database data.

Calculating the individualized fraction regime in stereotactic body radiotherapy for non-small cell lung cancer based on uncomplicated tumor control probability function

BACKGROUND

To calculate the individualized fraction regime (IFR) in stereotactic body radiotherapy (SBRT) for non-small cell lung cancer (NSCLC) patients using the uncomplicated tumor control probability (UTCP, P⁺) function.

METHODS

Thirty-three patients with peripheral lung cancer or lung metastases who had undergone SBRT were analyzed. Treatment planning was performed using the dose regime of 48 Gy in 4 fractions. Dose volume histogram (DVH) data for the gross tumor volume (GTV), lung, chest wall (CW) and rib were exported and the dose bin was multiplied by a certain percentage of the dose in that bin which ranged from 1 to 200% in steps of 1%. For each dose fraction, P⁺ values were calculated by considering the tumor control probability (TCP), radiation-induced pneumonitis (RIP), chest wall pain (CWP) and radiation-induced rib fracture (RIRF). UTCP values as a function of physical dose were plotted and the maximum P⁺ values corresponded to the optimal therapeutic gain. The IFR in 3 fractions was also calculated with the same method by converting the dose using the linear quadratic (LQ) model.

RESULTS

Thirty-three patients attained an IFR using the introduced methods. All the patients achieved a TCP value higher than 92.0%. The IFR ranged from 3 × 10.8 Gy to 3 × 12.5 Gy for 3 fraction regimes and from 4 × 9.2 Gy to 4 × 10.7 Gy for 4 fraction regimes. Four patients with typical tumor characteristics demonstrated that the IFR was patient-specific and could maximize the therapeutic gain. Patients with a large tumor had a lower TCP and UTCP and a smaller fractional dose than patients with a small tumor. Patients with a tumor adjacent to the organ at risk (OAR) or at a high risk of RIP had a lower UTCP and a smaller fractional dose compared with patients with a tumor located distant from the OAR.

CONCLUSIONS

The proposed method is capable of predicting the IFR for NSCLC patients undergoing SBRT. Further validation in clinical samples is required.

[Analysis of Clavien-Dindo classification and its prognosis factors of complications after laparoscopic right hemicolectomy]

Objective: To analyze the Clavien-Dindo classification of complications after right hemicolectomy and to explore the prognosis factors for postoperative complications. Methods: The retrospective case-control study was adopted. The clinical data of 176 patients who underwent right hemicolectomy at Department of General Surgery, Peking Union Medical College Hospital from October 2016 to February 2018 were collected. There were 95 male and 81 female patients with age of (62.4±12.7) years. The Clavien-Dindo classification was used for postoperative complications. Univariate and multivariate analysis were used to analyze the independent prognosis factors of complications after right colon resection. Results: Of the 176 patients, 2 patients had intraoperative complications (1.1%) and 39 patients had postoperative complications (22.2%), of which 10 cases had more than two complications, with a total of 53 complications. The proportions of Clavien-Dindo grade Ⅰ, Ⅱ, Ⅲ and Ⅳ complications were 41.5% (22/53), 49.1% (26/53), 7.5% (4/53), and 1.9%(1/53). Postoperative complications were associated with age, smoking history of the last 1 year, combined organ resection, lymph node dissection, intracorporeal anastomosis, and preoperative blood AST and Ca levels (all P<0.05). The results of multivariate analysis showed that intracorporeal anastomosis (OR=5.62, 95% CI: 2.46 to 12.85, P=0.00), preoperative blood AST (OR=-0.009, 95% CI: -0.018 to 0.000, P=0.04) and Ca (OR=0.51, 95% CI: 0.08 to 0.95, P=0.02) levels were independent prognosis factors affecting complications after right hemicolectomy. Conclusions: Complications of right hemicolectomy were mainly Clavien-Dindo grade Ⅰ and Ⅱ. Laparoscopic intracorporeal anastomosis should be carefully chosen, which may increase postoperative complications.

Comparison of Three Radiobiological Models in Stereotactic Body Radiotherapy for Non-Small Cell Lung Cancer

Objective: The applicability of the linear quadratic (LQ) model to local control (LC) modeling after hypofractionated radiotherapy to treat lung cancer is highly debated. To date, the differences in predicted outcomes between the LQ model and other radiobiological models, which are characterized by additional dose modification beyond a certain transitional dose (d_T), have not been well established. This study aims to compare the outcomes predicted by the LQ model with those predicted by two other radiobiological models in stereotactic body radiotherapy (SBRT) for non-small cell lung cancer (NSCLC). Methods: Computer tomography (CT) simulation data sets for 20 patients diagnosed with stage Ⅰ primary NSCLC were included in this study. Three radiobiological models, including the LQ, the universal survival curve (USC) and the modified linear quadratic and linear (mLQL) model were employed to predict the tumor control probability (TCP) data. First, the d_T values for the USC and mLQL models were determined. Then, the biologically effective dose (BED) and the predicted TCP values from the LQ model were compared with those calculated from the USC and mLQL models. Results: The d_T values from the USC model were 29.6 Gy, 33.8 Gy and 44.5 Gy, whereas the values were 90.2 Gy, 84.0 Gy and 57.3 Gy for the mLQL model for 1-year, 2-year and 3-year TCP prediction. The remarkable higher d_T values obtained from the mLQL model revealed the same dose-response relationship as the LQ model in the low- and high-dose ranges. We also found that TCP prediction from the LQ and USC models differed by less than 3%, although the BED values for the two models were significantly different. Conclusion: Radiobiological analysis reveals small differences between the models and suggested that the LQ model is applicable for modeling LC using SBRT to treat lung cancer, even when an extremely high fractional dose is used.

[Oncological outcomes analysis of colorectal cancer with unfavorable histological features]

Objective: To explore the effect of unfavorable histological features on the clinical outcomes of patients receiving radical resection of colorectal cancer. Methods: A retrospective analysis of patients with colorectal cancer who received radical surgery between January 2013 and December 2015 at Department of General Surgery, Peking Union Medical College Hospital was performed. The impact of unfavorable histological features on the oncological outcomes of patients with lymph node-negative colorectal cancer were analyzed.A total of 167 patients were enrolled, including 98 males and 69 females with age of (63.6±11.6) years. Observation indicators included age, T stage, lymphovascular invasion, perineural invasion, tumor deposits, number of lymph node dissection, degree of differentiation, tissue type, and circumferential margin. Univariate analysis was performed with χ(2) test and multivariate analysis was performed with Cox regression model. Results: Univariate analysis showed that positive circumferential margins (CRM), tumor deposits and age were associated with disease free survival (DFS) rate; positive CRM, age, tumor deposits, and lymph nodes dissection less than 12 were significantly associated with overall survival (OS) rate (all P<0.05). Multivariate analysis showed that over 70 years of age (HR=1.053, 95% CI: 1.013 to 1.095, P=0.009), poorly differentiated adenocarcinoma (HR=7.572, 95%CI: 1.815 to 31.587, P=0.005), tumor deposits (HR=4.711, 95% CI: 1.809 to 12.264, P=0.002), mucinous adenocarcinoma (HR=3.063, 95% CI: 1.003 to 9.354, P=0.049), lymphovascular invasion (HR=2.885, 95% CI: 1.062 to 7.832, P=0.038), and nerve infiltration (HR=6.610, 95% CI: 1.037 to 42.122, P=0.046) were adverse prognostic factors of DFS rate; poorly differentiated adenocarcinoma (HR=12.200, 95% CI: 1.985 to 74.972, P=0.007), tumor nodules (HR=5.379, 95% CI: 1.636 to 17.685, P=0.006), over 70 years of age (HR=1.062, 95% CI: 1.013 to 1.114, P=0.013), and perineural invasion (HR=8.043, 95% CI: 1.026 to 63.055, P=0.047) were adverse prognostic factors of OS rate. There was no significant difference in the 3-year DFS rate and 3-year OS rate between T1-2 group and T3-4 group (P>0.05). Conclusion: Over 70 years of age, poorly differentiated adenocarcinoma, mucinous adenocarcinoma, tumor nodules, lymphovascular invasion, and perineural invasion are independent adverse prognostic factors of lymph node-negative colorectal cancer.

[A case of human infection with highly pathogenic avian influenza A (H7N9) virus through poultry processing without protection measure]

Objective: To investigate the infection pattern and etiological characteristics of a case of human infection with highly pathogenic avian influenza A (H7N9) virus and provide evidence for the prevention and control of human infection with highly pathogenic avian influenza virus. Methods: Epidemiological investigation was conducted to explore the case's exposure history, infection route and disease progression. Samples collected from the patient, environments and poultry were tested by using real time reverse transcriptase-polymerase chain reaction (RT-PCR). Virus isolation, genome sequencing and phylogenetic analysis were conducted for positive samples. Results: The case had no live poultry contact history, but had a history of pulled chicken processing without taking protection measure in an unventilated kitchen before the onset. Samples collected from the patient's lower respiratory tract, the remaining frozen chicken meat and the live poultry market were all influenza A (H7N9) virus positive. The isolated viruses from these positive samples were highly homogenous. An insertion which lead to the addition of multiple basic amino acid residues (PEVPKRKRTAR/GL) was found at the HA cleavage site, suggesting that this virus might be highly pathogenic. Conclusions: Live poultry processing without protection measure is an important infection mode of "poultry to human" transmission of avian influenza viruses. Due to the limitation of protection measures in live poultry markets in Guangzhou, it is necessary to promote the standardized large scale poultry farming, the complete restriction of live poultry sales and centralized poultry slaughtering as well as ice fresh sale.

[Willingness and influencing factors related to "centralized slaughtering, fresh poultry listing and marketing" strategy among the household chefs in Guangzhou]

Objective: To study the willingness and influence factors related to "centralized slaughtering, fresh poultry listing and marketing" strategy, among the household chefs, and provide reference for government to adjust and optimize the strategy on avian influenza prevention. Methods: According to the geographical characteristics and regional functions, 6 'monitoring stations' were selected from 12 residential districts of Guangzhou, respectively. Another 21 meat markets which selling live poultry, were selected in each station and 5 household chefs of each market were invited to attend a face to face interview. Basic information, personal cognitive, willingness and influencing factors to the policy were under study. Univariate and multivariate logistic regression methods were used. Results: A total of 664 household chefs underwent the survey and results showed that the rate of support to the "centralized slaughtering, fresh poultry listing and marketing" strategy was 44.6% (296/664). Results from the multi-factor logistic regression showed that those household chefs who were males (OR=1.618, 95% CI: 1.156-2.264, P=0.005), having received higher education (OR=1.814, 95% CI: 1.296-2.539, P=0.001), or believing that the existence of live poultry stalls was related to the transmission of avian influenza (OR=1.918, 95% CI: 1.341-2.743, P<0.001) were factors at higher risk. These household chefs also intended to avoid the use of live poultry stalls (OR=1.666, 95%CI: 1.203-2.309, P=0.002) and accept the "centralized slaughtering, fresh poultry listing and marketing" strategy. Conclusion: Detailed study on this subject and, setting up pilot project in some areas as well as prioritizing the education programs for household chefs seemed helpful to the implementation of the 'freezing-fresh poultry' policy.

Comparative Analysis of Local Control Prediction Using Different Biophysical Models for Non-Small Cell Lung Cancer Patients Undergoing Stereotactic Body Radiotherapy

PURPOSE

The consistency for predicting local control (LC) data using biophysical models for stereotactic body radiotherapy (SBRT) treatment of lung cancer is unclear. This study aims to compare the results calculated from different models using the treatment planning data.

MATERIALS AND METHODS

Treatment plans were designed for 17 patients diagnosed with primary non-small cell lung cancer (NSCLC) using 5 different fraction schemes. The Martel model, Ohri model, and the Tai model were used to predict the 2-year LC value. The Gucken model, Santiago model, and the Tai model were employed to estimate the 3-year LC data.

RESULTS

We found that the employed models resulted in completely different LC prediction except for the Gucken and the Santiago models which exhibited quite similar 3-year LC data. The predicted 2-year and 3-year LC values in different models were not only associated with the dose normalization but also associated with the employed fraction schemes. The greatest difference predicted by different models was up to 15.0%.

CONCLUSIONS

Our results show that different biophysical models influence the LC prediction and the difference is not only correlated to the dose normalization but also correlated to the employed fraction schemes.

[Clinical application and prognostic analysis of interventional treatment for cesarean scar pregnancy]

OBJECTIVE

To analyze the clinical value and prognosis of cesarean scar pregnancy (CSP) treated by uterine artery embolization (UAE).

METHODS

In the study, 492 cases of patients in Nanjing Maternal and Child Health Care Hospital Affiliated to Nanjing Medical University diagnosed as CSP between January 2011 and December 2014 were chosen, of which 283 were of high-risk group and 209 of low-risk group. According to whether to take UAE, the high-risk group was subdivided into high-risk UAE group(UAE+laparoscopic group), 167 cases, and high-risk non UAE group (chemotherapy+laparoscopic group), 116 cases, while the low-risk group was subdivided into low-risk UAE group (UAE+curettage group), 113 cases, and low-risk non UAE group(chemotherapy+curettage group), 96 cases. The differences of the intraoperative bleeding, length of stay, blood beta human chorionic gonadotropin (β-HCG) dropped to normal time, menstruation recovery time and the hospitalization expenses were compared. And multivariate regression analysis was used to predict the recurrence risk of CSP.

RESULTS

The high-risk UAE group was better than the high-risk non UAE group in comparison of intraoperative bleeding [(36.5±14.8) mL vs.(76.5±39.7) mL], length of stay [(5.9±0.9) d vs.(9.6±1.3) d], blood β-HCG dropped to normal time [(17.9±8.7) d vs.(28.7±10.1) d] and menstruation recovery time [(18.1±1.6) d vs.(24.3±1.8) d],while the low-risk UAE group was better than the low-risk non UAE group in comparison of intraoperative bleeding [(93.2±43.3) mL vs.(284.8±110.5) mL], length of stay [(10.2±1.4) d vs. (30.7±9.6) d], blood β-HCG dropped to normal time [(50.1±17.6)d vs.(67.5±22.9)d] and menstruation recovery time[(56.3±6.7)d vs.(65.9±9.3) d], all P<0.05. The high-risk UAE group was higher than the high-risk non UAE group in comparison of hospitalization expenses [(20 140±1 520 )Yuan vs.(13 510±1 013) Yuan], and the low-risk group UAE was also higher than the low-risk non UAE group in comparison of hospitalization expenses [(10 095±962 )Yuan vs.(3 890±457) Yuan], all P<0.01. Multivariate Logistic regression analysis showed that the treatment method was independent predictor of CSP recurrence risk (OR 2.407, 95%CI 1.176-5.092, P<0.05), and using the comprehensive treatment including UAE could reduce the risk of recurrent CSP.

CONCLUSION

As the efficacy of interventional therapy for CSP was rapid and reliable, fewer complications, faster recovery and lower recurrence, hospitalization with good conditions, and particularly for those patients with CSP who want to fertility again, the comprehensive treatment including UAE treatment should be the first choice.

A dosimetric and treatment efficiency evaluation of stereotactic body radiation therapy for peripheral lung cancer using flattening filter free beams

To investigate potential dosimetric benefits and treatment efficiency of dynamic conformal arc therapy (DCA), intensity modulated radiation therapy (IMRT), and double partial arcs Rapidarc (RA) techniques in the treatment of early-stage peripheral lung cancer using stereotactic body radiotherapy (SBRT) with flattening filter free (FFF) beams. Twenty early-stage peripheral lung cancer patients were selected. For each patient, DCA, IMRT and RA plans were created to meet Radiation Therapy Oncology Group (RTOG) 0915 objectives with 48 Gy covering 95% of the planning target volume (PTV) in 4 fractions. PTV coverage, organs at risk (OARs) doses, planning time, monitor units (MU) and treatment time were evaluated. RA was significantly better than DCA for PTV coverage. RA provided a lower V32Gy to chest wall and less V20Gy to lung over those of DCA and IMRT. For other OARs, there is no significant difference among all three techniques. DCA plans showed significantly less planning time, shorter treatment time and lower MU number than those of RA and IMRT. RA provides a superior dosimetric benefit to DCA and IMRT in the treatment of early-stage lung cancer using SBRT with FFF beams. Considering the MU number, planning time and treatment efficiency, DCA technique is an effective treatment strategy.

Effects of omitting elective neck irradiation to nodal Level IB in nasopharyngeal carcinoma patients with negative Level IB lymph nodes treated by intensity-modulated radiotherapy: a Phase 2 study

OBJECTIVE

To investigate the need for elective neck irradiation (ENI) to nodal Level IB in patients with nasopharyngeal carcinoma (NPC) with negative Level IB lymph nodes (IB-negative) treated by intensity-modulated radiotherapy (IMRT).

METHODS

We conducted a Phase 2 prospective study in 123 newly diagnosed IB-negative patients with NPC treated by IMRT, who met at least 1 of the following criteria: (1) unilateral or bilateral Level II involvement with 1 of the following: Level IIA involvement or any Level II node ≥2 cm/with extracapsular spread; (2) ≥2 unilateral node-positive regions. Bilateral Level IB nodes were not contoured as part of the treatment target and treated electively. Level IB regional recurrence rate; pattern of treatment failure; 3-year overall survival (3y-OS), 3-year local control (3y-LC) and 3-year regional control (3y-RC) rates; toxicities; and dosimetric data for planning target volumes, organs at risk, Level IB and submandibular glands (SMGs) were evaluated.

RESULTS

Two patients developed failures at Level IB (1.6%). The 3y-LC, 3y-RC and 3y-OS rates were 93.5%, 93.5% and 78.0%, respectively. Bilateral Level IB received unplanned high-dose irradiation with a mean dose (Dmean) ≥50 Gy in 60% of patients. The average Dmean of bilateral SMGs was approximately 53 Gy.

CONCLUSION

ENI to Level IB may be unnecessary in IB-negative patients with NPC treated by IMRT. A further Phase 3 study is warranted.

ADVANCES IN KNOWLEDGE

Based on the results of this first Phase 2 study, we suggest omitting ENI to Level IB in Ib-negative patients with NPC with extensive nodal disease treated by IMRT.

[Investigate the radical extent of lymphadenectomy of right colon cancer]

Considering radical surgeries of right colon cancer, the reasonable extent of lymphadenectomy has always been argued. The concept of complete mesocolic excision (CME) has recently been established and optimized, which follows similar oncological principles as total mesorectal excision (TME) does for rectal cancer and is recommended by more and more surgeons. Studies published so far in the literature have been comprehensively reviewed, they do not, however, provide convincing evidence that demonstrate the standardized operation indications. Moreover, the existence of potential surgical risk and discernible oncological benefit has not been determined. Thus future studies are needed to further investigate the safety and efficacy of CME surgery, as has been demonstrated with TME such that it should become the procedure of choice in surgical practice.

Dosimetric analysis of isocentrically shielded volumetric modulated arc therapy for locally recurrent nasopharyngeal cancer

This study aimed to investigate the dosimetric characteristics of an isocentrically shielded RapidArc (IS-RA) technique for treatment of locally recurrent nasopharyngeal cancer (lrNPC). In IS-RA, the isocenter was placed at the center of the pre-irradiated brainstem (BS)/spinal cord (SC) and the jaws were set to shield the BS/SC while ensuring the target coverage during the whole gantry rotation. For fifteen patients, the IS-RA plans were compared with the conventional RapidArc (C-RA) regarding target coverage, organ-at-risk (OAR) sparing and monitor units (MUs). The relationship between the dose reduction of BS/SC and some geometric parameters including the angle extended by the target with respect to the axis of BS/SC (Ang_BSSC), the minimum distance between the target and BS/SC (Dist_Min) and the target volume were evaluated. The IS-RA reduced the BS/SC doses by approximately 1-4 Gy on average over the C-RA, with more MUs. The IS-RA demonstrated similar target coverage and sparing of other OARs except for slightly improved sparing of optic structures. More dose reduction in the isocentric region was observed in the cases with larger Ang_BSSC or smaller Dist_Min. Our results indicated that the IS-RA significantly improves the sparing of BS/SC without compromising dosimetric requirements of other involved structures for lrNPC.

Dosimetric evaluation of a simple planning method for improving intensity-modulated radiotherapy for stage III lung cancer

This study aimed to evaluate the dosimetric outcomes of a base-dose-plan-compensation (BDPC) planning method for improving intensity-modulated radiotherapy (IMRT) for stage III lung cancer. For each of the thirteen included patients, three types of planning methods were applied to obtain clinically acceptable plans: (1) the conventional optimization method (CO); (2) a split-target optimization method (STO), in which the optimization objectives were set higher dose for the target with lung density; (3) the BDPC method, which compensated for the optimization-convergence error by further optimization based on the CO plan. The CO, STO and BDPC methods were then compared regarding conformity index (CI), homogeneity index (HI) of the target, organs at risk (OARs) sparing and monitor units (MUs). The BDPC method provided better HI/CI by 54%/7% on average compared to the CO method and by 38%/3% compared to the STO method. The BDPC method also spared most of the OARs by up to 9%. The average MUs of the CO, STO and BDPC plans were 890, 937 and 1023, respectively. Our results indicated that the BDPC method can effectively improve the dose distribution in IMRT for stage III lung cancer, at the expense of more MUs.

Flattening Filter-Free Beams in Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy for Sinonasal Cancer

PURPOSE

To evaluate the dosimetric impacts of flattening filter-free (FFF) beams in intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for sinonasal cancer.

METHODS

For fourteen cases, IMRT and VMAT planning was performed using 6-MV photon beams with both conventional flattened and FFF modes. The four types of plans were compared in terms of target dose homogeneity and conformity, organ-at-risk (OAR) sparing, number of monitor units (MUs) per fraction, treatment time and pure beam-on time.

RESULTS

FFF beams led to comparable target dose homogeneity, conformity, increased number of MUs and lower doses to the spinal cord, brainstem and normal tissue, compared with flattened beams in both IMRT and VMAT. FFF beams in IMRT resulted in improvements by up to 5.4% for sparing of the contralateral optic structures, with shortened treatment time by 9.5%. However, FFF beams provided comparable overall OAR sparing and treatment time in VMAT. With FFF mode, VMAT yielded inferior homogeneity and superior conformity compared with IMRT, with comparable overall OAR sparing and significantly shorter treatment time.

CONCLUSIONS

Using FFF beams in IMRT and VMAT is feasible for the treatment of sinonasal cancer. Our results suggest that the delivery mode of FFF beams may play an encouraging role with better sparing of contralateral optic OARs and treatment efficiency in IMRT, but yield comparable results in VMAT.

A Dosimetric Study of Using Fixed-Jaw Volumetric Modulated Arc Therapy for the Treatment of Nasopharyngeal Carcinoma with Cervical Lymph Node Metastasis

PURPOSE

To study the dosimetric difference between fixed-jaw volumetric modulated radiotherapy (FJ-VMAT) and large-field volumetric modulated radiotherapy (LF-VMAT) for nasopharyngeal carcinoma (NPC) with cervical lymph node metastasis.

METHODS

Computed tomography (CT) datasets of 10 NPC patients undergoing chemoradiotherapy were used to generate LF-VMAT and FJ-VMAT plans in the Eclipse version 10.0 treatment planning system. These two kinds of plans were then compared with respect to planning-target-volume (PTV) coverage, conformity index (CI), homogeneity index (HI), organ-at-risk sparing, monitor units (MUs) and treatment time (TT).

RESULTS

The FJ-VMAT plans provided lower D2% of PGTVnd (PTV of lymph nodes), PTV1 (high-risk PTV) and PTV2 (low-risk PTV) than did the LF-VMAT plans, whereas no significant differences were observed in PGTVnx (PTV of primary nasopharyngeal tumor). The FJ-VMAT plans provided lower doses delivered to the planning organ at risk (OAR) volumes (PRVs) of both brainstem and spinal cord, both parotid glands and normal tissue than did the LF-VMAT plans, whereas no significant differences were observed with respect to the oral cavity and larynx. The MUs of the FJ-VMAT plans (683 ± 87) were increased by 22% ± 12% compared with the LF-VMAT plans (559 ± 62). In terms of the TT, no significant difference was found between the two kinds of plans.

CONCLUSIONS

FJ-VMAT was similar or slightly superior to LF-VMAT in terms of PTV coverage and was significantly superior in terms of OAR sparing, at the expense of increased MUs.

Monitor unit optimization in stereotactic body radiotherapy for small peripheral non-small cell lung cancer patients

The increasingly attractive stereotactic body radiotherapy (SBRT) treatment for stage I lung cancer is concomitant with a large amount of monitor units (MU), leading to excessive out-of-field dose and prolonged beam-on time. The study aims to reduce the MU number and shorten the beam-on time by optimizing the planning parameters. Clinically acceptable treatment plans from fourteen patients suffered from peripheral stage I non-small cell lung cancer (NSCLC) were created in the study. Priority for the upper objective of the target (PUOT), strength and Max MU setting in the MU objective function (MUOF) were adjusted respectively to investigate their effect on MU number, organs at risk (OARs) sparing and beam-on time. We found that the planning parameters influenced the MU number in a PUOT, strength and Max MU dependent manner. Combined with high priority for the UOT (HPUOT) and MUOF, the MU number was reduced from 443 ± 25 to 228 ± 22 MU/Gy without compromising the target coverage and OARs sparing. We also found beam-on time was proportional to MU number and it could be shortened from 7.9 ± 0.5 to 4.1 ± 0.4 minutes.

Radiobiological modeling analysis of the optimal fraction scheme in patients with peripheral non-small cell lung cancer undergoing stereotactic body radiotherapy

This study aimed to determine the optimal fraction scheme (FS) in patients with small peripheral non-small cell lung cancer (NSCLC) undergoing stereotactic body radiotherapy (SBRT) with the 4 × 12 Gy scheme as the reference. CT simulation data for sixteen patients diagnosed with primary NSCLC or metastatic tumor with a single peripheral lesion ≤3 cm were used in this study. Volumetric modulated arc therapy (VMAT) plans were designed based on ten different FS of 1 × 25 Gy, 1 × 30 Gy, 1 × 34 Gy, 3 × 15 Gy, 3 × 18 Gy, 3 × 20 Gy, 4 × 12 Gy, 5 × 12 Gy, 6 × 10 Gy and 10 × 7 Gy. Five different radiobiological models were employed to predict the tumor control probability (TCP) value. Three other models were utilized to estimate the normal tissue complication probability (NTCP) value to the lung and the modified equivalent uniform dose (mEUD) value to the chest wall (CW). The 1 × 30 Gy regimen is recommended to achieve 4.2% higher TCP and slightly higher NTCP and mEUD values to the lung and CW compared with the 4 × 12 Gy schedule, respectively. This regimen also greatly shortens the treatment duration. However, the 3 × 15 Gy schedule is suggested in patients where the lung-to-tumor volume ratio is small or where the tumor is adjacent to the CW.

Comparison of Two RapidArc Delivery Strategies in Stereotactic Body Radiotherapy of Peripheral Lung Cancer with Flattening Filter Free Beams

PURPOSE

To investigate the performance of using partial arc (PA) and full arc with avoidance sectors (FAAS) in stereotactic body radiotherapy (SBRT) of peripheral lung cancer with flattening filter free (FFF) beams.

METHODS

Eighteen patients with primary (T1 or T2) non-small-cell lung cancer (NSCLC) or lung metastatic were selected for this study. Nine patients with a gross tumor volume (GTV) <= 10 cc were designated as the small tumor group. The other nine patients with a GTV between 10 cc and 44 cc were assigned to the large tumor group. The treatment plans were generated in eighteen patients using PA and FAAS techniques, respectively, and delivered with a Varian TrueBeam Linac. Dosimetry of the target and organs at risk (OARs), monitor unit (MU), out-of-field dose, and delivery time were statistically analyzed. Delta4 and portal dosimetry were employed to evaluate the delivery accuracy.

RESULTS

For the small tumor group, compared with the PA plans, the FAAS plans significantly achieved a lower MU/fraction, out-of-field dose and a shorter treatment time (p<0.05), but the target dose was slightly higher than that delivered by PA plans (p<0.05). For the large tumor group, the PA plans significantly attained a shorter treatment time (p<0.05), whereas MU/fraction, out-of-field dose and dose to OARs were comparable between the two plans (p>0.05). Furthermore, all plans generated from the eighteen patients achieved a high pass rate in patient-specific quality assurance, with all the gamma indices greater than 97% at the Γ3mm, 3% threshold.

CONCLUSION

This study suggests that the FAAS technique is more beneficial for the small tumor patients undergoing lung SBRT with FFF beams because of its higher treatment efficiency and MU reduction. However, for the large tumor patients, the PA technique is recommended due to its higher treatment efficiency.

Volumetric modulated arc therapy vs. c-IMRT for the treatment of upper thoracic esophageal cancer

OBJECTIVE

To compare plans using volumetric-modulated arc therapy (VMAT) with conventional sliding window intensity-modulated radiation therapy (c-IMRT) to treat upper thoracic esophageal cancer (EC).

METHODS

CT datasets of 11 patients with upper thoracic EC were identified. Four plans were generated for each patient: c-IMRT with 5 fields (5F) and VMAT with a single arc (1A), two arcs (2A), or three arcs (3A). The prescribed doses were 64 Gy/32 F for the primary tumor (PTV64). The dose-volume histogram data, the number of monitoring units (MUs) and the treatment time (TT) for the different plans were compared.

RESULTS

All of the plans generated similar dose distributions for PTVs and organs at risk (OARs), except that the 2A- and 3A-VMAT plans yielded a significantly higher conformity index (CI) than the c-IMRT plan. The CI of the PTV64 was improved by increasing the number of arcs in the VMAT plans. The maximum spinal cord dose and the planning risk volume of the spinal cord dose for the two techniques were similar. The 2A- and 3A-VMAT plans yielded lower mean lung doses and heart V50 values than the c-IMRT. The V20 and V30 for the lungs in all of the VMAT plans were lower than those in the c-IMRT plan, at the expense of increasing V5, V10 and V13. The VMAT plan resulted in significant reductions in MUs and TT.

CONCLUSION

The 2A-VMAT plan appeared to spare the lungs from moderate-dose irradiation most effectively of all plans, at the expense of increasing the low-dose irradiation volume, and also significantly reduced the number of required MUs and the TT. The CI of the PTVs and the OARs was improved by increasing the arc-number from 1 to 2; however, no significant improvement was observed using the 3A-VMAT, except for an increase in the TT.

More accurate definition of clinical target volume based on the measurement of microscopic extensions of the primary tumor toward the uterus body in international federation of gynecology and obstetrics Ib-IIa squamous cell carcinoma of the cervix

PURPOSE

To more accurately define clinical target volume for cervical cancer radiation treatment planning by evaluating tumor microscopic extension toward the uterus body (METU) in International Federation of Gynecology and Obstetrics stage Ib-IIa squamous cell carcinoma of the cervix (SCCC).

PATIENTS AND METHODS

In this multicenter study, surgical resection specimens from 318 cases of stage Ib-IIa SCCC that underwent radical hysterectomy were included. Patients who had undergone preoperative chemotherapy, radiation, or both were excluded from this study. Microscopic extension of primary tumor toward the uterus body was measured. The association between other pathologic factors and METU was analyzed.

RESULTS

Microscopic extension toward the uterus body was not common, with only 12.3% of patients (39 of 318) demonstrating METU. The mean (±SD) distance of METU was 0.32 ± 1.079 mm (range, 0-10 mm). Lymphovascular space invasion was associated with METU distance and occurrence rate. A margin of 5 mm added to gross tumor would adequately cover 99.4% and 99% of the METU in the whole group and in patients with lymphovascular space invasion, respectively.

CONCLUSION

According to our analysis of 318 SCCC specimens for METU, using a 5-mm gross tumor volume to clinical target volume margin in the direction of the uterus should be adequate for International Federation of Gynecology and Obstetrics stage Ib-IIa SCCC. Considering the discrepancy between imaging and pathologic methods in determining gross tumor volume extent, we recommend a safer 10-mm margin in the uterine direction as the standard for clinical practice when using MRI for contouring tumor volume.

Improving target coverage and organ-at-risk sparing in intensity-modulated radiotherapy for cervical oesophageal cancer using a simple optimisation method

PURPOSE

To assess the performance of a simple optimisation method for improving target coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) for cervical oesophageal cancer.

METHODS

For 20 selected patients, clinically acceptable original IMRT plans (Original plans) were created, and two optimisation methods were adopted to improve the plans: 1) a base dose function (BDF)-based method, in which the treatment plans were re-optimised based on the original plans, and 2) a dose-controlling structure (DCS)-based method, in which the original plans were re-optimised by assigning additional constraints for hot and cold spots. The Original, BDF-based and DCS-based plans were compared with regard to target dose homogeneity, conformity, OAR sparing, planning time and monitor units (MUs). Dosimetric verifications were performed and delivery times were recorded for the BDF-based and DCS-based plans.

RESULTS

The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans. The BDF-based method further reduced the doses delivered to the OARs by approximately 1-3%. The re-optimisation time was reduced by approximately 28%, but the MUs and delivery time were slightly increased. All verification tests were passed and no significant differences were found.

CONCLUSION

The BDF-based method for the optimisation of IMRT for cervical oesophageal cancer can achieve significantly better dose distributions with better planning efficiency at the expense of slightly more MUs.

Dosimetric Evaluation of a Simple Planning Technique for Improving Intensity-Modulated Radiotherapy for Nasopharyngeal Cancer

PURPOSE

To evaluate the dosimetric outcomes of a simple planning technique for improving intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer (NPC).

METHODS

For 39 NPC cases, generally acceptable original plans were generated and were improved by the two planning techniques, respectively: (1) a basal-dose-compensation (BDC) technique, in which the treatment plans were re-optimized based on the original plans; (2) a local-dose-control (LDC) technique, in which the original plans were re-optimized with constraints for hot and cold spots. The BDC, original, and LDC plans were then compared regarding homogeneity index (HI) and conformity index (CI) of planning target volumes (PTVs), organ-at-risk (OAR) sparing and monitor units (MUs) per fraction. The whole planning times were also compared between the BDC and LDC plans.

RESULTS

The BDC plans had superior HIs / CIs, by 13-24% / 3-243%, respectively, over the original plans. Compared to the LDC plans, the BDC plans provided better HIs only for PTVnx (the PTV of nasopharyngeal primary tumor) by 11% and better CIs for all PTVs by 2-134%. The BDC technique spared most OARs, by 1-9%. The average MUs of the BDC, original, and LDC plans were 2149, 2068 and 2179, respectively. The average whole planning times were 48 and 69 minutes for the BDC and LDC plans, respectively.

CONCLUSIONS

For the IMRT of nasopharyngeal cancer, the BDC planning technique can improve target dose homogeneity, conformity and OAR sparing, with better planning efficiency.

Changes in the PD-1 and PD-L1 expressions of splenic dendritic cells in multiple-organ dysfunction syndrome mice and their significance

The aim of this study was to evaluate the expression of surface molecules in splenic dendritic cells (DC) in multiple-organ dysfunction syndrome (MODS) mice and their effects on the immunosuppression of sepsis and MODS. One hundred thirty C57BL/6 mice were divided into 7 groups: 6, 12, 24, 48 h, 5-7 days, 10-12 days, and the normal control group. The sepsis-MODS mouse model was established by zymson injection into the peritoneal cavity. Histopathological changes in the spleen were evaluated by hematoxylin and eosin (HE) staining. After enrichment with BDTM IMag, the expressions of PD-1, PD-L1, MHC-II (I-A(b)), and CD86 in splenic DCs were examined by flow cytometry, and their relationship with sepsis development and MODS was analyzed. The histological structures of the spleen were damaged in the 24-, 48-h, and 10-12-day groups. PD-L1 expression increased 6 h after zymosan injection, decreased to normal levels at 24 and 48 h, and increased at 5-7 days, peaking at 10-12 days. The change in PD-1 expression roughly paralleled that of PD-L1. MHC-II and CD86 increased at 6 and 12 h, and dropped to normal levels at 10-12 days. In the early stage of injury, splenic DCs were mainly activated, whereas in the later stage, the expressions of the negative co-stimulatory molecules, PD-L1 and PD- 1, were upregulated, similar to tolerogenic DCs. Splenic DCs might suppress the stimulation of T lymphocytes in MODS mice through the PD-L1/PD-1 pathway, which would induce immunosuppression and the pathogenesis of MODS.

Transmission of avian influenza A(H7N9) virus from father to child: a report of limited person-to-person transmission, Guangzhou, China, January 2014

We investigated a possible person-to-person transmission within a family cluster of two confirmed influenza A(H7N9) patients in Guangzhou, China. The index case, a man in his late twenties, worked in a wet market that was confirmed to be contaminated by the influenza A(H7N9) virus. He developed a consistent fever and severe pneumonia after 4 January 2014. In contrast, the second case, his five-year-old child, who only developed a mild disease 10 days after disease onset of the index case, did not have any contact with poultry and birds but had unprotected and very close contact with the index case. The sequences of the haemagglutinin (HA) genes of the virus stains isolated from the two cases were 100% identical. These findings strongly suggest that the second case might have acquired the infection via transmission of the virus from the sick father. Fortunately, all 40 close contacts, including the other four family members who also had unprotected and very close contact with the cases, did not acquire influenza A(H7N9) virus infection, indicating that the person-to-person transmissibility of the virus remained limited. Our finding underlines the importance of carefully, thoroughly and punctually following-up close contacts of influenza A(H7N9) cases to allow detection of any secondary cases, as these may constitute an early warning signal of the virus's increasing ability to transmit from person-to-person.