1.A study and application of rapid and precise dose measurement based on Gafchromic EBT4 film in FLASH radiotherapy
Yi ZHANG ; Yiwei YANG ; Yinghong TANG ; Shilan WANG ; Peng WU ; Qin YANG ; Xufan HUANG ; Yin LUO ; Yu JIANG ; Wenjun LUO ; Guiqiang ZOU ; Hua FENG ; Yinxiang HU
Chinese Journal of Radiological Medicine and Protection 2025;45(11):1144-1151
Objective:To establish a rapid and precise dose measurement method with EBT4 film and ensure its measurement accuracy to be within the required range through strict operational procedures for the purpose of addressing the two essential issues of poor measurement accuracy and timeliness of EBT film under FLASH conditions.Methods:After storing under different humidity conditions for a certain period of time, the film was exposed to radiation for analyzing the influence of air humidity on the intrinsic performance of EBT film. By means of repeated scanning operations and the film angle rotation, the influences of repeated scanning and film placement angle were analuzed. Parabolic correction method was used to reduce the spatial position influence during the scanning process. By analying the relationship between net optical density (netOD) and absorbed dose through the comparison of three fitting method, the optimal fitting curve was selected. After irradiation of the same batch of films for 5 min and 24 h, the film doses were calibrated and then compared with ionization chamber-measured result. The rapid and precise film dosimetry method was used to measure both the percentage depth dose from X-rays at ultra-high dose rate and the dose distribution at a depth of 2 cm in water.Results:Air humidity had the greatest influence on the intrinsic performance of EBT film (approximately 20%). The average deviation of repeated scans is within 0.5%. The angle at which the film is placed significantly affected the readouts of the film with the maximum influence approximately 70%. The net optical density combined with polynomial fitting can control the fitting residuals of 1-16 Gy within 3%. The change rate of light channels at 5 min already mostly met the requirements of the rapid mode (< 0.5%). Compared with the measurement result obtained using the reference ionization chamber, the deviations of the 5 min or 24 h dose calibration curves were all within 2%.Conclusions:The EBT4 film can be employed as a precise dosimeter to quickly measure the FLASH radiation dose. Rapid and precise FLASH dose measurements can meet the stringent requirements of both preclinical and clinical FLASH research.
2.Study on the Relative Weight Divisions of Diagnosis-related Groups for both Common and Complex Diseases
Yin CHEN ; Yiwei HAO ; Xiaoyu LIU
Chinese Journal of Health Statistics 2025;42(1):12-17
Objective To examine the classification of difficult and common diseases based on the weight of diagnosis related groups and to provide data support for performance evaluation and effect evaluation of the hierarchy medical system.Methods The CN-DRG grouping scheme was utilized to categorize the data from 3188340 medical records into 738 groups in 2022.The disease group performed k-medoids clustering.our clustering models were simulated,and the optimal model was determined by evaluating the explanatory power of each model using specific indicators.Subsequently,the relative weight ranges of DRG for common and difficult diseases were established.Results The optimal clustering model was identified using four indicators:the average length of stay,the proportion of patients admitted to intensive care units,the proportion of patients using ventilators,and the average cost per patient.The relative weight for common and difficult diseases was 0.97 for medical treatment,while for surgical treatment,it was 2.13.Conclusion This study is the first to define the weight ranges of diagnosis-related groups for common and difficult diseases by analyzing resource consumption and treatment outcomes.The findings provide a valuable measurement tool for hospital functional positioning and the evaluation of clinical specialty capabilities.
3.Study on the Relative Weight Divisions of Diagnosis-related Groups for both Common and Complex Diseases
Yin CHEN ; Yiwei HAO ; Xiaoyu LIU
Chinese Journal of Health Statistics 2025;42(1):12-17
Objective To examine the classification of difficult and common diseases based on the weight of diagnosis related groups and to provide data support for performance evaluation and effect evaluation of the hierarchy medical system.Methods The CN-DRG grouping scheme was utilized to categorize the data from 3188340 medical records into 738 groups in 2022.The disease group performed k-medoids clustering.our clustering models were simulated,and the optimal model was determined by evaluating the explanatory power of each model using specific indicators.Subsequently,the relative weight ranges of DRG for common and difficult diseases were established.Results The optimal clustering model was identified using four indicators:the average length of stay,the proportion of patients admitted to intensive care units,the proportion of patients using ventilators,and the average cost per patient.The relative weight for common and difficult diseases was 0.97 for medical treatment,while for surgical treatment,it was 2.13.Conclusion This study is the first to define the weight ranges of diagnosis-related groups for common and difficult diseases by analyzing resource consumption and treatment outcomes.The findings provide a valuable measurement tool for hospital functional positioning and the evaluation of clinical specialty capabilities.
4.A study and application of rapid and precise dose measurement based on Gafchromic EBT4 film in FLASH radiotherapy
Yi ZHANG ; Yiwei YANG ; Yinghong TANG ; Shilan WANG ; Peng WU ; Qin YANG ; Xufan HUANG ; Yin LUO ; Yu JIANG ; Wenjun LUO ; Guiqiang ZOU ; Hua FENG ; Yinxiang HU
Chinese Journal of Radiological Medicine and Protection 2025;45(11):1144-1151
Objective:To establish a rapid and precise dose measurement method with EBT4 film and ensure its measurement accuracy to be within the required range through strict operational procedures for the purpose of addressing the two essential issues of poor measurement accuracy and timeliness of EBT film under FLASH conditions.Methods:After storing under different humidity conditions for a certain period of time, the film was exposed to radiation for analyzing the influence of air humidity on the intrinsic performance of EBT film. By means of repeated scanning operations and the film angle rotation, the influences of repeated scanning and film placement angle were analuzed. Parabolic correction method was used to reduce the spatial position influence during the scanning process. By analying the relationship between net optical density (netOD) and absorbed dose through the comparison of three fitting method, the optimal fitting curve was selected. After irradiation of the same batch of films for 5 min and 24 h, the film doses were calibrated and then compared with ionization chamber-measured result. The rapid and precise film dosimetry method was used to measure both the percentage depth dose from X-rays at ultra-high dose rate and the dose distribution at a depth of 2 cm in water.Results:Air humidity had the greatest influence on the intrinsic performance of EBT film (approximately 20%). The average deviation of repeated scans is within 0.5%. The angle at which the film is placed significantly affected the readouts of the film with the maximum influence approximately 70%. The net optical density combined with polynomial fitting can control the fitting residuals of 1-16 Gy within 3%. The change rate of light channels at 5 min already mostly met the requirements of the rapid mode (< 0.5%). Compared with the measurement result obtained using the reference ionization chamber, the deviations of the 5 min or 24 h dose calibration curves were all within 2%.Conclusions:The EBT4 film can be employed as a precise dosimeter to quickly measure the FLASH radiation dose. Rapid and precise FLASH dose measurements can meet the stringent requirements of both preclinical and clinical FLASH research.
5.A Study on the Relationship between Spatial Absorption Capacity and Disease Structure of Inpatients with Infectious Diseases in Beijing General Hospitals
Yiwei HAO ; Xiaoyu LIU ; Yin CHEN ; Feng LU ; Meng JIA ; Moning GUO
Chinese Health Economics 2024;43(11):1-5,10
Objective:To study the relationship between the absorptive capacity of inpatients with infectious diseases and the structure of diseases in 65 secondary and tertiary general hospitals in Beijing,and to objectively analyze the current situation of space utilization of inpatients with infectious diseases,so as to provide data support for the formulation of relevant policies.Methods:The variability of spatial absorption capacity indicators for secondary and tertiary general hospitals in 6 urban districts and 10 suburbs were compared separately,and the correlation between the spatial absorption capacity of secondary and tertiary general hospitals and the structure of disease types was visualized and analyzed using quadrant bubble charts.Results:In terms of spatial absorption capacity,there was a statistically significant difference in the proportion of patients from suburban districts treated in the secondary and tertiary general hospitals in 6 urban districts of the Beijing(P=0.003),while there was no statistically significant difference in the proportion of patients from other districts treated in the secondary and tertiary general hospitals in 10 suburbs(P=0.336).The spatial absorption capacity and disease structure of the secondary and tertiary hospitals in 6 urban districts and the tertiary hospitals in 10 suburbs showed significant correlation,while the secondary hospitals in 10 suburbs showed no significant correlation.Conclusion:The tertiary general hospitals in 6 urban districts have superior infectious disease type structure indicators,with significantly stronger spatial absorption capacity and stronger correlation between these two,which plays the function of inpatient service of difficult and severe infectious diseases.Only the district hospitals in the outer suburbs can provide inpatient services for infectious diseases,and the number of cases admitted is large,which meets the needs of inpatient diagnosis and treatment of common infectious diseases in the district.It is necessary to strengthen the investment of infectious disease medical resources and capacity building in 10 suburban districts according to the actual situation.
6.Quantitative Analysis on Infectious Disease Service Capacity of Secondary and Tertiary General Hospitals in Beijing Based on CMI and Number of DRG Groups
Yiwei HAO ; Xiaoyu LIU ; Yin CHEN ; Feng LU ; Moning GUO ; Meng JIA
Chinese Health Economics 2024;43(11):6-10
Objective:The service capacity of infectious diseases department in Beijing secondary and tertiary general hospitals was quantitatively analyzed to provide objective data support for the construction of infectious diseases department.Methods:The scope of infectious diseases was defined by the DRG tool,and the service capacity of medical institutions was described by the Case Mix Index(CMI)and number of DRG groups.The differences in the service capacity of infectious diseases in 67 secondary and tertiary general hospitals in Beijing from 2016 to 2020 were analyzed by data visualization and generalized linear equation,and the disease structure of different hospitals at different levels was compared by selecting representative hospitals.Results:From 2016 to 2020,the mean CMI of tertiary hospitals ranged from 0.94 to 0.97,while that of secondary hospitals ranged from 0.70 to 0.72.From 2016 to 2019,the average number of DRG groups in tertiary hospitals ranged from 26.75 to 27.79,and the average number of DRG groups in secondary hospitals ranged from 15.32 to 15.77,and the average number of DRG groups in secondary and tertiary hospitals showed a significant decline in 2020.CMI and number of DRG groups had statistical significant difference at hospital level(P<0.001),and number of DRG groups had statistical difference in time dimension(P<0.001).Conclusion:The infectious disease service capacity of tertiary general hospitals is obviously stronger than that of secondary general hospitals,and the infectious disease medical service capacity of large tertiary hospitals is obviously ahead,while the overall service level of secondary hospitals is low.We should give full play to the advantages of top three hospitals to build a high ground for infectious disease department construction,and combine the spatial distribution of medical resources and demand characteristics to improve the infectious disease service capacity of secondary hospitals.
7.A Study on the Relationship between Spatial Absorption Capacity and Disease Structure of Inpatients with Infectious Diseases in Beijing General Hospitals
Yiwei HAO ; Xiaoyu LIU ; Yin CHEN ; Feng LU ; Meng JIA ; Moning GUO
Chinese Health Economics 2024;43(11):1-5,10
Objective:To study the relationship between the absorptive capacity of inpatients with infectious diseases and the structure of diseases in 65 secondary and tertiary general hospitals in Beijing,and to objectively analyze the current situation of space utilization of inpatients with infectious diseases,so as to provide data support for the formulation of relevant policies.Methods:The variability of spatial absorption capacity indicators for secondary and tertiary general hospitals in 6 urban districts and 10 suburbs were compared separately,and the correlation between the spatial absorption capacity of secondary and tertiary general hospitals and the structure of disease types was visualized and analyzed using quadrant bubble charts.Results:In terms of spatial absorption capacity,there was a statistically significant difference in the proportion of patients from suburban districts treated in the secondary and tertiary general hospitals in 6 urban districts of the Beijing(P=0.003),while there was no statistically significant difference in the proportion of patients from other districts treated in the secondary and tertiary general hospitals in 10 suburbs(P=0.336).The spatial absorption capacity and disease structure of the secondary and tertiary hospitals in 6 urban districts and the tertiary hospitals in 10 suburbs showed significant correlation,while the secondary hospitals in 10 suburbs showed no significant correlation.Conclusion:The tertiary general hospitals in 6 urban districts have superior infectious disease type structure indicators,with significantly stronger spatial absorption capacity and stronger correlation between these two,which plays the function of inpatient service of difficult and severe infectious diseases.Only the district hospitals in the outer suburbs can provide inpatient services for infectious diseases,and the number of cases admitted is large,which meets the needs of inpatient diagnosis and treatment of common infectious diseases in the district.It is necessary to strengthen the investment of infectious disease medical resources and capacity building in 10 suburban districts according to the actual situation.
8.Quantitative Analysis on Infectious Disease Service Capacity of Secondary and Tertiary General Hospitals in Beijing Based on CMI and Number of DRG Groups
Yiwei HAO ; Xiaoyu LIU ; Yin CHEN ; Feng LU ; Moning GUO ; Meng JIA
Chinese Health Economics 2024;43(11):6-10
Objective:The service capacity of infectious diseases department in Beijing secondary and tertiary general hospitals was quantitatively analyzed to provide objective data support for the construction of infectious diseases department.Methods:The scope of infectious diseases was defined by the DRG tool,and the service capacity of medical institutions was described by the Case Mix Index(CMI)and number of DRG groups.The differences in the service capacity of infectious diseases in 67 secondary and tertiary general hospitals in Beijing from 2016 to 2020 were analyzed by data visualization and generalized linear equation,and the disease structure of different hospitals at different levels was compared by selecting representative hospitals.Results:From 2016 to 2020,the mean CMI of tertiary hospitals ranged from 0.94 to 0.97,while that of secondary hospitals ranged from 0.70 to 0.72.From 2016 to 2019,the average number of DRG groups in tertiary hospitals ranged from 26.75 to 27.79,and the average number of DRG groups in secondary hospitals ranged from 15.32 to 15.77,and the average number of DRG groups in secondary and tertiary hospitals showed a significant decline in 2020.CMI and number of DRG groups had statistical significant difference at hospital level(P<0.001),and number of DRG groups had statistical difference in time dimension(P<0.001).Conclusion:The infectious disease service capacity of tertiary general hospitals is obviously stronger than that of secondary general hospitals,and the infectious disease medical service capacity of large tertiary hospitals is obviously ahead,while the overall service level of secondary hospitals is low.We should give full play to the advantages of top three hospitals to build a high ground for infectious disease department construction,and combine the spatial distribution of medical resources and demand characteristics to improve the infectious disease service capacity of secondary hospitals.
9.A Study on the Relationship between Spatial Absorption Capacity and Disease Structure of Inpatients with Infectious Diseases in Beijing General Hospitals
Yiwei HAO ; Xiaoyu LIU ; Yin CHEN ; Feng LU ; Meng JIA ; Moning GUO
Chinese Health Economics 2024;43(11):1-5,10
Objective:To study the relationship between the absorptive capacity of inpatients with infectious diseases and the structure of diseases in 65 secondary and tertiary general hospitals in Beijing,and to objectively analyze the current situation of space utilization of inpatients with infectious diseases,so as to provide data support for the formulation of relevant policies.Methods:The variability of spatial absorption capacity indicators for secondary and tertiary general hospitals in 6 urban districts and 10 suburbs were compared separately,and the correlation between the spatial absorption capacity of secondary and tertiary general hospitals and the structure of disease types was visualized and analyzed using quadrant bubble charts.Results:In terms of spatial absorption capacity,there was a statistically significant difference in the proportion of patients from suburban districts treated in the secondary and tertiary general hospitals in 6 urban districts of the Beijing(P=0.003),while there was no statistically significant difference in the proportion of patients from other districts treated in the secondary and tertiary general hospitals in 10 suburbs(P=0.336).The spatial absorption capacity and disease structure of the secondary and tertiary hospitals in 6 urban districts and the tertiary hospitals in 10 suburbs showed significant correlation,while the secondary hospitals in 10 suburbs showed no significant correlation.Conclusion:The tertiary general hospitals in 6 urban districts have superior infectious disease type structure indicators,with significantly stronger spatial absorption capacity and stronger correlation between these two,which plays the function of inpatient service of difficult and severe infectious diseases.Only the district hospitals in the outer suburbs can provide inpatient services for infectious diseases,and the number of cases admitted is large,which meets the needs of inpatient diagnosis and treatment of common infectious diseases in the district.It is necessary to strengthen the investment of infectious disease medical resources and capacity building in 10 suburban districts according to the actual situation.
10.Quantitative Analysis on Infectious Disease Service Capacity of Secondary and Tertiary General Hospitals in Beijing Based on CMI and Number of DRG Groups
Yiwei HAO ; Xiaoyu LIU ; Yin CHEN ; Feng LU ; Moning GUO ; Meng JIA
Chinese Health Economics 2024;43(11):6-10
Objective:The service capacity of infectious diseases department in Beijing secondary and tertiary general hospitals was quantitatively analyzed to provide objective data support for the construction of infectious diseases department.Methods:The scope of infectious diseases was defined by the DRG tool,and the service capacity of medical institutions was described by the Case Mix Index(CMI)and number of DRG groups.The differences in the service capacity of infectious diseases in 67 secondary and tertiary general hospitals in Beijing from 2016 to 2020 were analyzed by data visualization and generalized linear equation,and the disease structure of different hospitals at different levels was compared by selecting representative hospitals.Results:From 2016 to 2020,the mean CMI of tertiary hospitals ranged from 0.94 to 0.97,while that of secondary hospitals ranged from 0.70 to 0.72.From 2016 to 2019,the average number of DRG groups in tertiary hospitals ranged from 26.75 to 27.79,and the average number of DRG groups in secondary hospitals ranged from 15.32 to 15.77,and the average number of DRG groups in secondary and tertiary hospitals showed a significant decline in 2020.CMI and number of DRG groups had statistical significant difference at hospital level(P<0.001),and number of DRG groups had statistical difference in time dimension(P<0.001).Conclusion:The infectious disease service capacity of tertiary general hospitals is obviously stronger than that of secondary general hospitals,and the infectious disease medical service capacity of large tertiary hospitals is obviously ahead,while the overall service level of secondary hospitals is low.We should give full play to the advantages of top three hospitals to build a high ground for infectious disease department construction,and combine the spatial distribution of medical resources and demand characteristics to improve the infectious disease service capacity of secondary hospitals.

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