Objective To conduct Monte Carlo simulations on the microselectro-HDR¹⁹²Ir radiation source, investigate dose distributions under various conditions, and provide assistance in optimizing radiotherapy plans. Methods A microselectro-HDR¹⁹²Ir radiation source model was established based on the MCNP5 software. Theoretical calculation formulas were used to validate the simulation results. The dose distributions under different activities and positions were obtained through simulations using the MCNP5 transport program. By fitting the simulation data, the relationship between the safe distance for at-risk organs and treatment time was analyzed. Results As the distance from the origin increased in the X-direction, the distance required for the absorbed dose rate to decrease to half its original value increased, and the isodose lines became sparser. The shapes of the dose distribution diagrams under different activities were consistent, presenting concentric polygons and concentric circles at different distances. Under the condition of the same lethal dose, the difference in the safe distance between two organs increased with time; under different lethal dose conditions, the differences were not significant whether between similar organs or between different organs. Conclusion The Monte Carlo method can accurately describe the radiation field generated by the microselectro-HDR¹⁹²Ir radioactive source during high-dose-rate brachytherapy. Quantitative analysis of the radiation field will help optimize the radiotherapy plan.

Objective To conduct Monte Carlo simulations on the microselectro-HDR¹⁹²Ir radiation source, investigate dose distributions under various conditions, and provide assistance in optimizing radiotherapy plans. Methods A microselectro-HDR¹⁹²Ir radiation source model was established based on the MCNP5 software. Theoretical calculation formulas were used to validate the simulation results. The dose distributions under different activities and positions were obtained through simulations using the MCNP5 transport program. By fitting the simulation data, the relationship between the safe distance for at-risk organs and treatment time was analyzed. Results As the distance from the origin increased in the X-direction, the distance required for the absorbed dose rate to decrease to half its original value increased, and the isodose lines became sparser. The shapes of the dose distribution diagrams under different activities were consistent, presenting concentric polygons and concentric circles at different distances. Under the condition of the same lethal dose, the difference in the safe distance between two organs increased with time; under different lethal dose conditions, the differences were not significant whether between similar organs or between different organs. Conclusion The Monte Carlo method can accurately describe the radiation field generated by the microselectro-HDR¹⁹²Ir radioactive source during high-dose-rate brachytherapy. Quantitative analysis of the radiation field will help optimize the radiotherapy plan.

Objective To conduct Monte Carlo simulations on the microselectro-HDR¹⁹²Ir radiation source, investigate dose distributions under various conditions, and provide assistance in optimizing radiotherapy plans. Methods A microselectro-HDR¹⁹²Ir radiation source model was established based on the MCNP5 software. Theoretical calculation formulas were used to validate the simulation results. The dose distributions under different activities and positions were obtained through simulations using the MCNP5 transport program. By fitting the simulation data, the relationship between the safe distance for at-risk organs and treatment time was analyzed. Results As the distance from the origin increased in the X-direction, the distance required for the absorbed dose rate to decrease to half its original value increased, and the isodose lines became sparser. The shapes of the dose distribution diagrams under different activities were consistent, presenting concentric polygons and concentric circles at different distances. Under the condition of the same lethal dose, the difference in the safe distance between two organs increased with time; under different lethal dose conditions, the differences were not significant whether between similar organs or between different organs. Conclusion The Monte Carlo method can accurately describe the radiation field generated by the microselectro-HDR¹⁹²Ir radioactive source during high-dose-rate brachytherapy. Quantitative analysis of the radiation field will help optimize the radiotherapy plan.

Objective We conducted a survey on the awareness rate of stroke in Yangquan residents and analyzed factors affecting awareness to provide basic information for Yangquan residents to prevent and treat stroke in Shanxi.MethodsA questionnaire regarding awareness and basic knowledge of stroke was used in this study and applied to Yangquan residents.A cluster stratified sample of 7983 residents were questionnaired by cross-sectional method.Results7921 returned copies were valid.The awareness rate of stroke in 7921 selected Yangquan residents was 30.14％ (2387/7921). Upon the occurrence of stroke,the awareness rates of the way to see a doctor,the right department to look for medical care and test manners to diagnose the illness as stroke were relatively high in these investigated people,which were 74.03％ (5864/7921),78.17％ (6192/7921) and 84.04％ (6657/7921),respectively.However,the number of people who knew characteristic symptoms and complications of stoke,risk factors that cause stroke and how to treat stroke was 2021 (25.51％),841 ( 10.62％ ),and 902 ( 11.39％ ),respectively,which was relatively low. After multivariate analysis,the awareness rate of stroke in Yangquan residents was positively correlated with an education degree.ConclusionsYangquan residents know little about stroke.Therefore,it is necessary to increase the level of their knowledge regarding stroke by extended propaganda and encourage them to live a healthy life to be able to treat stoke in time and to reduce the possibility of stroke occurring.