1.Dosimetric comparison of 4 different volumetric modulated arc therapy plans for hippocampal-sparing prophylactic cranial irradiation
Meijiao WANG ; Jiacheng LIU ; Kaining YAO ; Yichen PU ; Jian GONG ; Fan JIANG ; Yi DU
Chinese Journal of Medical Physics 2025;42(7):853-862
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.
2.Knowledge acquisition and retention when implementing public health awareness training on common pediatric eye conditions in Thailand
Chan FOUNTANE ; Woodward MANI ; Parappilly MICHAEL ; Fan YICHEN ; Tedla SARON ; Tamornpark RATIPARK ; Anderson JAMIE ; Chomchoei CHALITAR ; Kampun MANASSAWIN ; Yeemard FARTIMA ; Srikua BUATHANYA ; White ELIZABETH ; Summers ALLISON
Global Health Journal 2025;9(1):27-36
Background:Low awareness of common pediatric eye conditions,such as amblyopia,conjunctivitis,and myopia in rural Chiang Rai,Thailand,prompted the development of a specialized curriculum.This curriculum aimed to provide individuals serving these areas with resources to educate and disseminate information within their communities.Methods:A one-hour curriculum covering the causes,signs,diagnosis,treatment,and prevention of amblyopia,conjunctivitis,and myopia was delivered virtually to public health students at a Thai university and in-person to students at this university and rural community members.The in-person seminar included hands-on activities and simulations of these eye conditions.Knowledge acquisition and retention were assessed using pre-tests,immediate post-tests,and one-month post-tests.Results:The seminar was attended by 87 virtual public health students,111 in-person public health students,and 40 in-person rural community members.All groups showed significant improvement in test scores from pre-test to immediate post-test(P<0.001).In-person students had 1.57 times the odds of answering correctly on the immediate post-test compared to virtual students,despite no significant difference in baseline knowledge.However,the subset of in-person students who did not receive bilingual materials showed no significant difference in immediate post-test performance compared to virtual students(P>0.05).Although public health students had more than twice the odds of answering correctly at pre-test compared to rural community members,there were no significant differences between groups on the immediate post-test(P>0.05).Conclusion:A brief seminar significantly improved understanding and retention of pediatric eye conditions,achieving similar levels of understanding among public health students and rural community members,regard-less of initial knowledge on this topic.In-person,hands-on seminars with educational materials in participants'preferred language proved more effective than virtual ones in achieving these improvements.
3.Dosimetric comparison of 4 different volumetric modulated arc therapy plans for hippocampal-sparing prophylactic cranial irradiation
Meijiao WANG ; Jiacheng LIU ; Kaining YAO ; Yichen PU ; Jian GONG ; Fan JIANG ; Yi DU
Chinese Journal of Medical Physics 2025;42(7):853-862
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.
4.Knowledge acquisition and retention when implementing public health awareness training on common pediatric eye conditions in Thailand
Chan FOUNTANE ; Woodward MANI ; Parappilly MICHAEL ; Fan YICHEN ; Tedla SARON ; Tamornpark RATIPARK ; Anderson JAMIE ; Chomchoei CHALITAR ; Kampun MANASSAWIN ; Yeemard FARTIMA ; Srikua BUATHANYA ; White ELIZABETH ; Summers ALLISON
Global Health Journal 2025;9(1):27-36
Background:Low awareness of common pediatric eye conditions,such as amblyopia,conjunctivitis,and myopia in rural Chiang Rai,Thailand,prompted the development of a specialized curriculum.This curriculum aimed to provide individuals serving these areas with resources to educate and disseminate information within their communities.Methods:A one-hour curriculum covering the causes,signs,diagnosis,treatment,and prevention of amblyopia,conjunctivitis,and myopia was delivered virtually to public health students at a Thai university and in-person to students at this university and rural community members.The in-person seminar included hands-on activities and simulations of these eye conditions.Knowledge acquisition and retention were assessed using pre-tests,immediate post-tests,and one-month post-tests.Results:The seminar was attended by 87 virtual public health students,111 in-person public health students,and 40 in-person rural community members.All groups showed significant improvement in test scores from pre-test to immediate post-test(P<0.001).In-person students had 1.57 times the odds of answering correctly on the immediate post-test compared to virtual students,despite no significant difference in baseline knowledge.However,the subset of in-person students who did not receive bilingual materials showed no significant difference in immediate post-test performance compared to virtual students(P>0.05).Although public health students had more than twice the odds of answering correctly at pre-test compared to rural community members,there were no significant differences between groups on the immediate post-test(P>0.05).Conclusion:A brief seminar significantly improved understanding and retention of pediatric eye conditions,achieving similar levels of understanding among public health students and rural community members,regard-less of initial knowledge on this topic.In-person,hands-on seminars with educational materials in participants'preferred language proved more effective than virtual ones in achieving these improvements.
5.Acceptance and commissioning tests for big bore CT simulator and quality control scheme
Meijiao WANG ; Jiacheng LIU ; Kaining YAO ; Jian GONG ; Zhongsu FENG ; Fan JIANG ; Shun ZHOU ; Yichen PU ; Jixiang CHEN ; Hao WU ; Yi DU
Chinese Journal of Medical Physics 2024;41(12):1460-1472
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.
6.Analysis of causes and solutions for vacuum suction weakness of dental units
Xinya LI ; Yichen WANG ; Yansong LIU ; Anjia ZHENG ; Shubin WU ; Baolin FAN ; Jianxia WANG
China Medical Equipment 2024;21(2):193-195,199
An efficient vacuum suction system is a necessary prerequisite for the smooth operation of the oral diagnosis and treatment.During the use of the dental units,there is often a situation of vacuum suction weakness,resulting in the inability to discharge the mixture of blood,saliva,dental tissue and other mixtures in time,which affects the doctor's treatment field and increases the risk of aspiration pneumonia and cross-infection in patients.The working principle,pipeline system,filters and other aspects of the vacuum suction system that may affect the suction efficiency was analyzed.The causes and solutions of vacuum suction weakness were discussed,and operation suggestions were proposed to ensure the safe and effective use of equipment and ensure the safety of diagnosis and treatment.
7.Risk factors for liver cancer in chronic hepatitis B patients and construction of a nomogram prediction model
Yichen ZHU ; Chunxia SHA ; Chunsun FAN ; Tiejun ZHANG
Journal of Clinical Hepatology 2024;40(12):2441-2449
ObjectiveTo investigate the risk factors for liver cancer in patients with chronic hepatitis B (CHB) in the Qidong Chronic Hepatitis B cohort, and to construct a nomogram model for predicting the risk of liver cancer in CHB patients. MethodsA structured questionnaire survey was conducted among the CHB patients, aged ≥18 years, who attended the outpatient service of Qidong Third People’s Hospital from January 1 to December 31, 2016. The onset of liver cancer was defined as the primary outcome, and the outcomes of the cohort were obtained from Qidong Cancer Registry. Baseline clinical features were compared ;between the liver cancer group and the non-liver cancer group. The independent-samples t test or the Mann-Whitney U test was used for comparison of continuous data between two groups, and the chi-square test or the Fisher’s exact test was used for comparison of categorical data between groups. The Cox regression model was used to analyze the risk factors for liver cancer in CHB patients and calculate their hazard ratio (HR) and 95% confidence interval (CI); the variables with statistical significance in the univariate Cox regression analysis were included in the LASSO regression analysis, and then the variables obtained were included in the multivariate Cox regression analysis to establish a predictive model. The nomogram was used to visualize the complex model. The receiver operating characteristic (ROC) curve, index of concordance (C-index), and the calibration curve were used to assess the predictive efficacy of the model, and the decision curve was used to evaluate the clinical practicability of the nomogram. ResultsA total of 1 479 CHB patients were selected, among whom 58 patients with a confirmed diagnosis of liver cancer, 15 with missing data on testing indicators, and 164 with missing data on important information in the questionnaire were excluded, and finally 1 242 subjects were included in the study. Up to December 31, 2023, there were 67 new cases of liver cancer after a median follow-up time of 7.71 years, and the incidence density of liver cancer was 729.78/100,000 person-years. There were significant differences between the liver cancer group and the non-liver cancer group in age, sex, educational level, liver cirrhosis, duration of liver cirrhosis, history of diabetes mellitus, albumin, total bilirubin (TBil), direct bilirubin, aspartate aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase (GGT), and alkaline phosphatase (all P<0.05). The multivariate Cox regression analysis showed that the increase in age (HR=1.07, 95%CI: 1.05 — 1.10, P<0.001), a relatively high level of TBil (HR=1.98, 95%CI: 1.15 — 3.42, P=0.014), a relatively high level of GGT (HR=2.41, 95%CI: 1.43 — 4.08, P=0.001), and a long duration of liver cirrhosis (HR=1.09, 95%CI: 1.02 — 1.15, P=0.009) were independent risk factors for liver cancer in CHB patients. A nomogram prediction model was constructed based on the above four indicators, with an area under the ROC curve of 0.790, 0.845, and 0.829, respectively, in predicting the risk of liver cancer in CHB patients at 1, 3, and 5 years, and the bootstrap resampling method was used for internal validation and showed a C-index of 0. 778. The calibration curve showed that the prediction model had good stability, and the decision curve showed that it had certain clinical practicability. ConclusionThe increase in age, relatively high levels of TBil and GGT, and a long duration of liver cirrhosis are independent risk factors for liver cancer in CHB patients, and the nomogram model constructed based on these factors has a good predictive value and can be used in clinical practice to help develop strategies for the long-term monitoring of liver cancer.
8.Acceptance and commissioning tests for big bore CT simulator and quality control scheme
Meijiao WANG ; Jiacheng LIU ; Kaining YAO ; Jian GONG ; Zhongsu FENG ; Fan JIANG ; Shun ZHOU ; Yichen PU ; Jixiang CHEN ; Hao WU ; Yi DU
Chinese Journal of Medical Physics 2024;41(12):1460-1472
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.
9.HIV/AIDS epidemic in the elderly and prevention and control challenges in China
Houlin TANG ; Yichen JIN ; Fan LYU
Chinese Journal of Epidemiology 2023;44(11):1669-1672
With the rapidly increase of HIV infections in the elderly in China, new challenges have emerged in HIV/AIDS prevention and control. Low awareness of HIV and common unprotected casual sex and commercial sex has made older people at higher risk for HIV infection. In addition, HIV-infected and higher risk elderly people have limited awareness of HIV-related knowledge and access to testing services due to low educational level and socioeconomic status. Furthermore, HIV-infected elderly people usually have elevated risk of death because of late detection and comorbidities of chronic diseases. More research should be made to further understand the behavioural characteristics and social, cultural and psychological determinants of the elderly, development and adoption of HIV prevention service strategy catering for the elderly's need, and strengthening whole-process comprehensive health management of elderly infected people.
10.Epidemiological characteristics and trend of HIV-infected patients aged 60 years and older reported in China, 2015-2022
Yichen JIN ; Houlin TANG ; Qianqian QIN ; Chang CAI ; Fangfang CHEN ; Fan LYU
Chinese Journal of Epidemiology 2023;44(11):1673-1678
Objective:To understand the epidemiological characteristics and changing trends of HIV-infected patients aged ≥60 years reported in recent years in China and provide reference for the development of HIV prevention and control strategies for the elderly.Methods:The data of newly reported HIV-infected patients aged ≥60 years between 2015 and 2022 were obtained from China Information System for Disease Control and Prevention. The differences in epidemiological characteristics of HIV infections among groups were compared by using t test and Kruskal-Wallis H nonparametric test in software SPSS 24.0. Software Joinpoint 4.9.0 was used to calculate annual percent change (APC) and trend analysis was conducted by using Joinpoint regression model. Software Excel 2019 was used for graph drawing. Results:The number of reported HIV-infected patients aged ≥60 years in China increased from 17 451 in 2015 to 27 004 in 2022, with newly diagnosed rate rising from 9.0/100 000 to 10.2/100 000. The newly diagnosed rate in men was higher than that in women. Trend analysis demonstrated that the newly diagnosed rate in both elderly men and women peaked in 2019 (APC for men=13.5%, P=0.003; APC for women=15.0%, P=0.002), and showed a downward trend after 2019 (APC for men=-12.4%, P=0.006; APC for women=-13.0%, P=0.007). Among the elderly infected men, those infected by heterosexual and homosexual transmission accounted for 93.5% (160 747/171 924) and 5.1% (8 781/171 924), respectively. Among the elderly infected women, those infected by heterosexual transmission accounted for 98.4% (48 899/49 697). The infected elder people diagnosed by medical institutions accounted for 71.5% (158 394/221 621), whose baseline CD4 +T lymphocytes level was lower than that in those diagnosed by other ways ( H=1 079.82, P<0.001). Conclusions:The poor risk awareness and high-risk sexual behavior made the elderly at higher risk for HIV infection. More efforts should be made to improve active surveillance, timely detection and origin-tracing for infected elderly for the accurate and effective prevention and control of HIV infection.

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