Objective To quantitatively compare the dosimetric differences among 4 volumetric modulated arc therapy(VMAT)plans by analyzing the number of arcs and collimator angle settings,aiming to establish a standardized planning template for hippocampal-sparing prophylactic cranial irradiation(HS-PCI)in clinic and improve both planning quality and clinical efficiency.Methods Twenty HS-PCI patients were enrolled,with 4 VMAT plans(V2c,V2p,V3,and V4)for each patient.The differences in target dose,organs-at-risk dose,and monitor units were compared.Results V4 plan had the highest PTV D98%and V95%,and the differences of PTV D98%in V2c vs V2p,V2c vs V4,and PTV V95%in V2c vs V4 were statistically significant(P<0.05).Meanwhile,V4 plan had the lowest PTV Dmax and Dmin doses.Specifically,statistically significant differences were observed in PTV Dmax in V4 vs V2c,V4 vs V2p,V4 vs V3,as well as PTV Dmin in V2c vs V2p,V2c vs V3,V2c vs V4,V2p vs V4(P<0.05).The PTV Dmean was the highest in V2p plan,with statistically significant differences observed in V2c vs V2p,V2c vs V4,V2p vs V3,and V3 vs V4(P<0.05).The highest PTV D2%dose was observed in V2p plan,and the differences in V2c vs V2p,V2c vs V4,V2p vs V3,V3 vs V4 were statistically significant(P<0.05).The homogeneity index and conformity index were close in 4 plans(P=0.946,P=0.380).V4 plan had the lowest Dmax,Dmean,and Dmin of the hippocampus,with significant differences in hippocampal Dmax in V4 vs V2c,V4 vs V2p,hippocampal Dmean in V4 vs V2c,V4 vs V2p,V3 vs V2c,and hippocampal Dmin in V2c vs V2p/V3/V4,and V4 vs V2p(P<0.05).V3 plan had the lowest Dmax for bilateral lenses,and V4 plan showed the lowest Dmax for lenses with a 3 mm expansion,with significant differences between V2c and V2p/V3/V4(P<0.05).V4 plan had the lowest dose for the right optic nerve,with significant differences in V4 vs V2p,and V4 vs V3(P<0.05).No significant differences were observed for the left optic nerve and optic chiasm.The monitor units in V2p plan was the lowest.Conclusion When differences in organs-at-risk doses and plan quality parameters are insignificant,V2p plan is recommended as it can ensure treatment quality while reducing delivery time.

Objective:To investigate the impact of chromate exposure on pulmonary function indices in occupational populations and explore the potential role of alterations in inflammatory indicators in this process.Methods:In July 2024, A cross-sectional analysis was conducted using occupational health examination data of 30875 workers from chromate-related enterprises in Jiangsu Province in 2020 and 2021. Based on the occupational positions and whether there is chromium acid salt exposure in the occupational hazards of the research subjects over the years, they are divided into chromium acid salt exposure group and non-exposure group. For those exposed to chromium acid salts, based on job position descriptions and duration of chromium acid salt exposure, they are further categorized into intermittent exposure group and continuous exposure group; among them, the actual exposure time in the intermittent exposure group is less than half of the working shift time, and the exposure duration is less than the total working life. Pulmonary function test indicators include forced vital capacity (forced vital capacity, FVC) %, first-second forced expiratory volume (forced expiratory volume in one second, FEV 1.0) %, and the ratio of first-second forced expiratory volume to forced vital capacity (FEV 1.0/FVC) %. Peripheral blood samples from the upper limbs of the research subjects were collected on an empty stomach for routine blood tests, selecting neutrophil count, platelet count, and lymphocyte count results, calculating the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Quantitative data that meet normal distribution are expressed using Mean±SD, while variables that do not meet normal distribution are represented by M ( Q1, Q3). Categorical data are expressed using frequency or proportion (%). Linear variable comparisons between groups use t-tests. Generalized linear models were employed to assess the correlation between chromate exposure and pulmonary function indices, while mixed regression models were utilized to explore potential underlying effects. Results:Compared with the non-exposed group, the pulmonary function indices FVC (%), FEV 1.0/FVC (%), and FEV 1.0 (%) in the chromate-exposed group showed a decreasing trend ( P<0.01), indicating statistically significant differences. As the frequency of chromate exposure increased, the prevalence of pulmonary dysfunction rose. The prevalence rates of obstructive, restrictive, and mixed respiratory dysfunction among the chromate-exposed population (including intermittent exposure and continuous exposure groups) were 0.26%, 4.67%, and 0.12%, which were higher than those in the non-exposed group (0.09%, 0.84%, and 0.07%, respectively). All these differences were statistically significant ( P<0.05). After stratification by gender, a negative correlation was observed between chromate exposure and the inflammatory indicator platelet-to-lymphocyte ratio (PLR) ( P<0.05). Potential effect analysis revealed that PLR played a certain mediating role between chromate exposure and the decline in pulmonary function indices, with a mediating proportion of 2.2%. Conclusion:Chromate exposure in occupational populations may lead to a decline in pulmonary ventilatory function and alterations in peripheral blood inflammatory indicators. Inflammatory indicators may be involved in the pulmonary function decline caused by chromate exposure.

Objective:By systematically evaluate the implementation of GBZ 2.1, so as to provide technical basis for the future revisions of this standard.Methods:From May to October 2023, Based on the pre survey questionnaire, the semi-structured interview method was used to interviews with experts from CDC, Occupational disease prevention and control hospital institutes, employers, occupational hygiene technical service intermediaries and universities, and the inductive method was used to extract the topics and relevant suggestions.Results:Generally, GBZ 2.1 is scientific, practical, progressiveness and operable. There are still some issues such as OELs overlapping and the correspondence between Chinese and English names. The outstanding problem is the coordination with other standard contents.Conclusion:The technical indicators in GBZ 2.1 could adapt to the needs of current practical work. The coordination between standards needs to be clarified, and the new recommended content needs further promotion and exploration on how to implement it.

Objective To quantitatively compare the dosimetric differences among 4 volumetric modulated arc therapy(VMAT)plans by analyzing the number of arcs and collimator angle settings,aiming to establish a standardized planning template for hippocampal-sparing prophylactic cranial irradiation(HS-PCI)in clinic and improve both planning quality and clinical efficiency.Methods Twenty HS-PCI patients were enrolled,with 4 VMAT plans(V2c,V2p,V3,and V4)for each patient.The differences in target dose,organs-at-risk dose,and monitor units were compared.Results V4 plan had the highest PTV D98%and V95%,and the differences of PTV D98%in V2c vs V2p,V2c vs V4,and PTV V95%in V2c vs V4 were statistically significant(P<0.05).Meanwhile,V4 plan had the lowest PTV Dmax and Dmin doses.Specifically,statistically significant differences were observed in PTV Dmax in V4 vs V2c,V4 vs V2p,V4 vs V3,as well as PTV Dmin in V2c vs V2p,V2c vs V3,V2c vs V4,V2p vs V4(P<0.05).The PTV Dmean was the highest in V2p plan,with statistically significant differences observed in V2c vs V2p,V2c vs V4,V2p vs V3,and V3 vs V4(P<0.05).The highest PTV D2%dose was observed in V2p plan,and the differences in V2c vs V2p,V2c vs V4,V2p vs V3,V3 vs V4 were statistically significant(P<0.05).The homogeneity index and conformity index were close in 4 plans(P=0.946,P=0.380).V4 plan had the lowest Dmax,Dmean,and Dmin of the hippocampus,with significant differences in hippocampal Dmax in V4 vs V2c,V4 vs V2p,hippocampal Dmean in V4 vs V2c,V4 vs V2p,V3 vs V2c,and hippocampal Dmin in V2c vs V2p/V3/V4,and V4 vs V2p(P<0.05).V3 plan had the lowest Dmax for bilateral lenses,and V4 plan showed the lowest Dmax for lenses with a 3 mm expansion,with significant differences between V2c and V2p/V3/V4(P<0.05).V4 plan had the lowest dose for the right optic nerve,with significant differences in V4 vs V2p,and V4 vs V3(P<0.05).No significant differences were observed for the left optic nerve and optic chiasm.The monitor units in V2p plan was the lowest.Conclusion When differences in organs-at-risk doses and plan quality parameters are insignificant,V2p plan is recommended as it can ensure treatment quality while reducing delivery time.

Objective:To investigate the impact of chromate exposure on pulmonary function indices in occupational populations and explore the potential role of alterations in inflammatory indicators in this process.Methods:In July 2024, A cross-sectional analysis was conducted using occupational health examination data of 30875 workers from chromate-related enterprises in Jiangsu Province in 2020 and 2021. Based on the occupational positions and whether there is chromium acid salt exposure in the occupational hazards of the research subjects over the years, they are divided into chromium acid salt exposure group and non-exposure group. For those exposed to chromium acid salts, based on job position descriptions and duration of chromium acid salt exposure, they are further categorized into intermittent exposure group and continuous exposure group; among them, the actual exposure time in the intermittent exposure group is less than half of the working shift time, and the exposure duration is less than the total working life. Pulmonary function test indicators include forced vital capacity (forced vital capacity, FVC) %, first-second forced expiratory volume (forced expiratory volume in one second, FEV 1.0) %, and the ratio of first-second forced expiratory volume to forced vital capacity (FEV 1.0/FVC) %. Peripheral blood samples from the upper limbs of the research subjects were collected on an empty stomach for routine blood tests, selecting neutrophil count, platelet count, and lymphocyte count results, calculating the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Quantitative data that meet normal distribution are expressed using Mean±SD, while variables that do not meet normal distribution are represented by M ( Q1, Q3). Categorical data are expressed using frequency or proportion (%). Linear variable comparisons between groups use t-tests. Generalized linear models were employed to assess the correlation between chromate exposure and pulmonary function indices, while mixed regression models were utilized to explore potential underlying effects. Results:Compared with the non-exposed group, the pulmonary function indices FVC (%), FEV 1.0/FVC (%), and FEV 1.0 (%) in the chromate-exposed group showed a decreasing trend ( P<0.01), indicating statistically significant differences. As the frequency of chromate exposure increased, the prevalence of pulmonary dysfunction rose. The prevalence rates of obstructive, restrictive, and mixed respiratory dysfunction among the chromate-exposed population (including intermittent exposure and continuous exposure groups) were 0.26%, 4.67%, and 0.12%, which were higher than those in the non-exposed group (0.09%, 0.84%, and 0.07%, respectively). All these differences were statistically significant ( P<0.05). After stratification by gender, a negative correlation was observed between chromate exposure and the inflammatory indicator platelet-to-lymphocyte ratio (PLR) ( P<0.05). Potential effect analysis revealed that PLR played a certain mediating role between chromate exposure and the decline in pulmonary function indices, with a mediating proportion of 2.2%. Conclusion:Chromate exposure in occupational populations may lead to a decline in pulmonary ventilatory function and alterations in peripheral blood inflammatory indicators. Inflammatory indicators may be involved in the pulmonary function decline caused by chromate exposure.

Objective:By systematically evaluate the implementation of GBZ 2.1, so as to provide technical basis for the future revisions of this standard.Methods:From May to October 2023, Based on the pre survey questionnaire, the semi-structured interview method was used to interviews with experts from CDC, Occupational disease prevention and control hospital institutes, employers, occupational hygiene technical service intermediaries and universities, and the inductive method was used to extract the topics and relevant suggestions.Results:Generally, GBZ 2.1 is scientific, practical, progressiveness and operable. There are still some issues such as OELs overlapping and the correspondence between Chinese and English names. The outstanding problem is the coordination with other standard contents.Conclusion:The technical indicators in GBZ 2.1 could adapt to the needs of current practical work. The coordination between standards needs to be clarified, and the new recommended content needs further promotion and exploration on how to implement it.

Objective:To investigate the safety and therapeutic effect of split liver transplantation (SLT) in clinical application.Methods:This is a retrospective case-series study. The clinical data of 203 consecutive SLT, 79 living donor liver transplantation (LDLT) and 1 298 whole liver transplantation (WLT) performed at the Third Affiliated Hospital of Sun Yat-sen University from July 2014 to July 2023 were retrospectively analyzed. Two hundred and three SLT liver grafts were obtained from 109 donors. One hundred and twenty-seven grafts were generated by in vitro splitting and 76 grafts were generated by in vivo splitting. There were 90 adult recipients and 113 pediatric recipients. According to time, SLT patients were divided into two groups: the early SLT group (40 cases, from July 2014 to December 2017) and the mature SLT technology group (163 cases, from January 2018 to July 2023). The survival of each group was analyzed and the main factors affecting the survival rate of SLT were analyzed. The Kaplan-Meier method and Log-rank test were used for survival analysis.Results:The cumulative survival rates at 1-, 3-, and 5-year were 74.58%, 71.47%, and 71.47% in the early SLT group, and 88.03%, 87.23%, and 87.23% in the mature SLT group, respectively. Survival rates in the mature SLT group were significantly higher than those in the early SLT group ( χ2=5.560, P=0.018). The cumulative survival rates at 1-, 3- and 5-year were 93.41%, 93.41%, 89.95% in the LDLT group and 87.38%, 81.98%, 77.04% in the WLT group, respectively. There was no significant difference among the mature SLT group, the LDLT group and the WLT group ( χ2=4.016, P=0.134). Abdominal hemorrhage, infection, primary liver graft nonfunction,and portal vein thrombosis were the main causes of early postoperative death. Conclusion:SLT can achieve results comparable to those of WLT and LDLT in mature technology liver transplant centers, but it needs to go through a certain time learning curve.

Objective:To investigate the safety and therapeutic effect of split liver transplantation (SLT) in clinical application.Methods:This is a retrospective case-series study. The clinical data of 203 consecutive SLT, 79 living donor liver transplantation (LDLT) and 1 298 whole liver transplantation (WLT) performed at the Third Affiliated Hospital of Sun Yat-sen University from July 2014 to July 2023 were retrospectively analyzed. Two hundred and three SLT liver grafts were obtained from 109 donors. One hundred and twenty-seven grafts were generated by in vitro splitting and 76 grafts were generated by in vivo splitting. There were 90 adult recipients and 113 pediatric recipients. According to time, SLT patients were divided into two groups: the early SLT group (40 cases, from July 2014 to December 2017) and the mature SLT technology group (163 cases, from January 2018 to July 2023). The survival of each group was analyzed and the main factors affecting the survival rate of SLT were analyzed. The Kaplan-Meier method and Log-rank test were used for survival analysis.Results:The cumulative survival rates at 1-, 3-, and 5-year were 74.58%, 71.47%, and 71.47% in the early SLT group, and 88.03%, 87.23%, and 87.23% in the mature SLT group, respectively. Survival rates in the mature SLT group were significantly higher than those in the early SLT group ( χ2=5.560, P=0.018). The cumulative survival rates at 1-, 3- and 5-year were 93.41%, 93.41%, 89.95% in the LDLT group and 87.38%, 81.98%, 77.04% in the WLT group, respectively. There was no significant difference among the mature SLT group, the LDLT group and the WLT group ( χ2=4.016, P=0.134). Abdominal hemorrhage, infection, primary liver graft nonfunction,and portal vein thrombosis were the main causes of early postoperative death. Conclusion:SLT can achieve results comparable to those of WLT and LDLT in mature technology liver transplant centers, but it needs to go through a certain time learning curve.

CT simulator has the functions such as original coordination positioning and radiotherapy resetting,and it can provide image and cooridiate information for radiotherapy.Through electronic density calibration,tissue inhomogeneity correction is carried out for supporting dose calculation in treatment planning system.With reference to relevant national standards,international guidelines,clinical functions of CT simulator and the practical experience of the center,a set of acceptance and commissioning testing scheme suitable for big bore CT simulator is presented,aiming to guide and assist the newly opened department in conducting comprehensive,safe and feasible acceptance and commissioning tests.The scheme includes the reference methods and tolerance standards of CT simulator machinery,image quality,radiation dose,radiotherapy related items and safety,so as to ensure the safety and accuracy of CT simulation and survival benefits.