1.Construction of an index system for assessment of schistosomiasis transmission risk following natural disasters
Jingye SHANG ; Chenghang YU ; Zisong WU ; Xianhong MENG ; Huirong XU ; Chaofu WANG ; Bin ZHENG ; Shizhu LI ; Yang LIU
Chinese Journal of Schistosomiasis Control 2026;38(1):60-68
Objective To construct an index system for assessment of schistosomiasis transmission risk following natural disasters such as rainstorms, floods, earthquakes, mudslides, and landslides, so as to provide insights into rapid identification of schistosomiasis transmission risk post-disasters and formulation of targeted schistosomiasis control strategies. Methods An initial framework for the index system for assessment of schistosomiasis transmission risk following natural disasters was drafted through literature review, brainstorming, and focus group discussions. Two rounds of expert correspondence consultations were conducted using the Delphi method to refine and finalize the system, and the degrees of expert activeness, authority and endorse ment, and consensus were evaluated. In addition, the weights of each index were calculated using the analytic hierarchy process. Results A total of 18 experts participated in the consultation. The expert positive coefficients were 100.00% and 94.44% for two rounds of consultations, with authority coefficients of 0.92 and 0.94, respectively. The coefficients of coordination on the index importance, rationality and operability were 0.209, 0.185, 0.222 and 0.407, 0.214, 0.257 for two rounds of consultations, respectively, and all consistency tests were statistically significant (χ2 = 246.771 to 505.278, all P values < 0.001). Following two rounds of expert consultations, an index system consisting of 6 first-level indicators, 15 second-level indicators, and 49 third-level indicators was ultimately constructed. In terms of first-level indicators, “disaster situation”, “previous epidemics”, “healthcare guarantee”, “response capacity” and “emergency recovery” had the highest weights, each at 18.18%. Regarding second-level indicators, “Schistosoma japonicum infections in animals”, “S. japonicum infections in snails” and “medical treatment” had the highest weights, each at 7.35%. In terms of third-level indicators, ten items had the highest weights, including “identification of schistosomiasis cases”, “detection of S. japonicum infections in wild feces”, “detection of S. japonicum infections in snails”, “reserves of schistosomiasis diagnostic/testing reagents and consumables”, “reserves of chemotherapy agents for human and animal schistosomiasis”, “reserves of cercariacides”, “periodical surveillance on schistosomiasis”, “identification of schistosomiasis transmission risk and timely response”, “normal provision of diagnosis and treatment services” and “post-disaster schistosomiasis surveillance”, each at 2.40%. Conclusion A scientific, systematic, and practical index system has been constructed for assessment of schistosomiasis transmission risk following natural disasters, which may provide insights into rapid post-disaster identification of schistosomiasis transmission risk, formulation of targeted schistosomiasis control strategies and optimization of resource allocation.
2.Clinical characteristics and genetic analysis of 22 Chinese pedigrees affected with Neurofibromatosis type I.
Bingjie HU ; Xianhong DING ; Yang LU ; Hongliang CHEN ; Shuaishuai CHEN ; Mengyi XU ; Yicheng FANG ; Bo SHEN
Chinese Journal of Medical Genetics 2026;43(1):19-30
OBJECTIVE:
To explore the genetic variants and phenotypic characteristics of patients with Neurofibromatosis type I (NF1).
METHODS:
Twenty two NF1 patients who presented at Enze Medical (Center) Group in Taizhou between 2018 and 2024 were selected as the study subjects. Clinical phenotype and family history were collected for the patients. Whole exome sequencing (WES) was carried out for the 22 probands to screen the variants of NF1 gene. Candidate variants were verified by Sanger sequencing of their family members. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: K20230902).
RESULTS:
The 22 probands were diagnosed between the age of 5 months to 47 years old, and have all shown cafe au lait spots on their skin. Seventeen patients exhibited the phenotype at birth, and 11 had various degrees of neurofibromatosis. Among them, probands 1 and 13 underwent surgical resection of the tumor but had recurred, while proband 12 had amputation due to the huge size and serious impact of the neurofibroma and had no recurrence. Five patients had various degrees of scoliosis. In total 22 germline mutations and one somatic mutation were identified among the 22 families, with 5 variants unreported previously, including 1 nonsense mutation c.1603C>T (Q535*), 3 frameshift mutations [c.7268_7269delCA (Thr2423fs), c.2293del (Arg765Alafs*26), and c.5433_5438delinsGC (Phe1812ArgfsTer50)], and 1 deletion involving exons 41-44 of the NF1 gene and adjacent introns. Proband 13 was found to harbor germline mutation c.6796C>T (Gln2266Ter) and somatic mutation c.1019_1020del (Ser340Cysfs Ter12) in the peripheral blood and tumor tissue, respectively. Among the 22 NF1 probands, 6 had received treatment due to severe illness. Proband 1 had tumor resection in the right upper limb, but was found to have malignant lung tumor and died during follow-up. Proband 12 had multiple recurrence of neurofibroma in the left ring finger. Proband 4 underwent spinal correction surgery due to severe scoliosis. Proband 11 had died due to a central nervous system disease. Among the 22 germline mutations, 6 had led to the occurrence of truncated proteins, which may have a more severe impact on the phenotype.
CONCLUSION
This study investigated the genetic variants and clinical phenotypes of 22 NF1 families and identified 5 novel variants of the NF1 gene, which has expanded the genotypic and phenotypic spectra of the NF1. Preliminary studies have identified an association between truncated mutations, young age, and severe phenotypes, which may provide important clues for prognosis evaluation. For the clinical diagnosis and treatment of NF1, it is necessary to consider the phenotypic characteristics and genetic testing in combination with genetic counseling and long-term follow-up.
Humans
;
Neurofibromatosis 1/pathology*
;
Male
;
Female
;
Pedigree
;
Adult
;
Child
;
Child, Preschool
;
Middle Aged
;
Adolescent
;
Infant
;
Young Adult
;
Neurofibromin 1/genetics*
;
Phenotype
;
Asian People/genetics*
;
Mutation
;
Exome Sequencing
;
East Asian People
3.Study on the Distribution Pattern and Driving Factors of Health Poverty among Middle-aged and Elderly People with Chronic Diseases
Hongyu LI ; Bing WU ; Chenxi ZHANG ; Yongqiang LAI ; Xinwei LIU ; Yulu TIAN ; Qianqian GE ; Xianhong HUANG ; Haijun YANG ; Fang YIN ; Yujuan XU ; Ye LI
Chinese Hospital Management 2025;45(3):40-44
Objective Based on the assumption of spatial heterogeneity,the distribution pattern and risk characteristics of health poverty in middle-aged and elderly people with chronic diseases are described from the perspective of spatial differentiation.In order to providing a theoretical basis for the optimization of subsequent poverty reduction policies and a model policy for other countries.Methods It used factor detector and interaction detector to capture the role of single-factor and multi-factor interactions on the spatial differentiation of health poverty,and risk detectors were utilized to explore the high-risk factors in risky areas Results The single factor explanation of medical assistance and health education activities is prominent,and the factors such as PM2.5,old-age dependency ratio and urban unemployment rate have strong interaction.Furthermore,it identified high-risk factor characteristics in areas at high risk of health poverty.Conclusion The spatial differentiation pattern of health poverty among the middle-aged and elderly chronic disease population in China is the result of the synergistic driving effect of multidimensional factors,and there is variability in the risk characteristics among regions.The government should establish a contextual optimization strategy and pay attention to the joint effect of multiple factors to establish a synergistic management system.
4.Analysis of FBN1 gene mutations in six Chinese pedigrees affected with Marfan syndrome
Xianhong DING ; Chenliang HONG ; Yang LU ; Mengyi XU ; Bingjie HU ; Yicheng FANG ; Bo SHEN
Chinese Journal of Medical Genetics 2025;42(1):41-50
Objective:To determine the types of genetic variants in six Chinese pedigrees affected with Marfan syndrome (MFS) and analyze their clinical characteristics and molecular pathogenesis.Methods:Six MFS pedigrees presented at the Taizhou Enze Medical Center (Group) between 2017 and 2022 were selected as the study subjects. Clinical data of pedigrees were retrospectively analyzed. Peripheral blood samples were collected from the probands and their family members for the extraction of genomic DNA. Whole exome sequencing (WES) was carried out. Candidate variants of the FBN1 gene were verified by Sanger sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), pathogenicity of the candidate variants was assessed. AlphaFold3 and PyMOL software were used for homology modeling of the FBN1 protein and analysis of its three-dimensional structure and amino acid sequence conservation. This study was approved by the Medical Ethics Committee of Taizhou Enze Medical Center (Group) (Ethics No. 20231002). Results:Cardiovascular system abnormalities were noted in all pedigrees, ocular abnormalities were present in pedigrees 2 and 5, skeletal system abnormalities were presented in pedigrees 1, and 4 to 6. FBN1 gene mutations were identified in all pedigrees, including c. 1957_1958dupGT (p.Asp654fs), c. 5014T>A (p.Cys1672Ser), c. 8135delC (p.Pro2712fs), c. 2302G>T (p.Glu768*), c. 3473A>G (p.Glu1158Gly) and c. 6169C>T (p.Arg2057*), with each involving a different exon. Four variants were rated as pathogenic, one as likely pathogenic, and one as variant of uncertain significance. Among these, c. 5014T>A (p.Cys1672Ser), c. 1957_1958dupGT (p.Asp654fs), c. 8135delC (p.Pro2712fs), and c. 2302G>T (p.Glu768*) were unreported previously. Bioinformatic analysis with SIFT and PolyPhen-2 predicted that the c. 5014T>A (p.Cys1672Ser) and c. 3473A>G (p.Glu1158Gly) variants were deleterious. Protein homologous sequence alignment analysis revealed that the four novel mutation sites are highly conserved across various species. Homology modeling of the FBN1 protein three-dimensional structure indicated that the six variant sites in the amino acid sequence are all close to hydrogen bonds and may alter the secondary and tertiary structures to varying degrees, thereby confirmed the relationship between the variants and MFS. Conclusion:Four novel variants of the FBN1 gene have been discovered in this study, which has enriched the mutational and phenotypic spectrum of MFS and provided a basis for disease diagnosis and genetic counseling.
5.A Geant4-based research on radiation field distribution in a 9 MeV e-FLASH treatment room
Deqi CHENG ; Qin YANG ; Xufan HUANG ; Peng WU ; Haoran XIE ; Jing XIA ; Erfeng WANG ; Guofu YU ; Yu JIANG ; Xianhong LIU
Chinese Journal of Radiological Medicine and Protection 2025;45(11):1152-1156
Objective:To investigate the radiation field distribution characteristics in a 9 MeV electron FLASH (e-FLASH) linear accelerator treatment room.Methods:The Geant4 Monte Carlo program was employed for physical simulating of the radiation field distribution inside and outside the treatment room under a single-beam delivery condition with a total dose of 50 Gy at the reference point and a dose rate of 250 Gy/s. High-sensitivity radiation detectors (AT1123) were used to validate the measurements at key points.Results:The dose rate at the reference point was approximately 9×10 11 μSv/h. Due to the scattering and shielding effects, the deviation of the attenuation rate from the inverse-square law was observed and the isodose lines exhibited spatial drift. Measured dose rates at key points showed good agreement with the simulation result, with a maximum deviation within 30%. Conclusions:The complex radiation field distribution can be effectively simulated using Geant4 in an e-FLASH treatment room. This indicated the Geant4 is not only applicable for the shielding calculations in e-FLASH radiotherapy facilities, but also for the design optimization through, reduction of trial-and-error iterations and engineering costs.
6.Sex difference of echocardiographic characteristics and prognosis in patients with moderate to severe bicuspid aortic stenosis
Baoqi FENG ; Feiwei LU ; Zheqing YANG ; Jun LI ; Cuizhen PAN ; Xianhong SHU ; Yongshi WANG
Chinese Journal of Clinical Medicine 2025;32(5):785-792
Objective To explore the sex difference in clinical manifestations, echocardiographic features and prognosis of patients with bicuspid aortic valve (BAV) combined with moderate to severe aortic stenosis (AS). Methods The clinical data and echocardiographic follow-up parameters of patients diagnosed with BAV combined with moderate to severe AS at Zhongshan Hospital, Fudan University, from July 30, 2010 to August 1, 2015 were retrospectively collected. The composite endpoint was defined as all-cause mortality or surgical intervention. Kaplan-Meier survival curve and log-rank test were used to compare the risk of composite endpoint events between male and female patients, and Cox regression models were used to analyze independent risk factors for composite endpoint events. Results A total of 144 patients were included, with 69 males and 75 females, and a median age of 60 years. Compared to males, female patients were younger (58[46, 65] years vs 61[54, 67] years, P=0.046), had a lower proportion of aortic valve calcification (61.1% vs 81.1%, P=0.009), and a higher peak transvalvular pressure gradient (72[59, 88] mmHg vs 63[55, 72] mmHg, P=0.002). In terms of left ventricular remodeling types, the proportion of concentric remodeling was higher in females than in males (36.0% vs 15.9%, P=0.006), while the proportion of eccentric hypertrophy was lower in females than in males (10.7% vs 29.0%, P=0.006). The proportion of female patients classified as New York Heart Association (NYHA) functional class Ⅲ-Ⅳ was higher than that of males (45.3% vs 17.4%, P<0.001), and left ventricular ejection fraction was higher in females (68%[65%, 72%] vs 65%[60%, 70%], P=0.003). With a median follow-up of 49 months, Kaplan-Meier survival analysis showed that the risk of composite endpoint events was higher in females than in males (P<0.001). Independent risk factors for composite endpoint events included female (HR=1.74, 95%CI 1.02-2.96, P=0.042), severe AS (HR=1.99, 95%CI 1.18-3.36, P=0.010), and NYHA functional class Ⅲ-Ⅳ (HR=2.08, 95% CI 1.24-3.47, P=0.005). Conclusions Sex significantly affects the clinical manifestations, echocardiographic characteristics, and prognosis of patients with BAV combined with moderate to severe AS, suggesting that sex-specific echocardiographic assessment and follow-up monitoring should be conducted for these patients.
7.Analysis of FBN1 gene mutations in six Chinese pedigrees affected with Marfan syndrome.
Xianhong DING ; Hongliang CHEN ; Yang LU ; Mengyi XU ; Bingjie HU ; Yicheng FANG ; Bo SHEN
Chinese Journal of Medical Genetics 2025;42(1):41-50
OBJECTIVE:
To determine the types of genetic variants in six Chinese pedigrees affected with Marfan syndrome (MFS) and analyze their clinical characteristics and molecular pathogenesis.
METHODS:
Six MFS pedigrees presented at the Taizhou Enze Medical Center (Group) between 2017 and 2022 were selected as the study subjects. Clinical data of pedigrees were retrospectively analyzed. Peripheral blood samples were collected from the probands and their family members for the extraction of genomic DNA. Whole exome sequencing (WES) was carried out. Candidate variants of the FBN1 gene were verified by Sanger sequencing. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), pathogenicity of the candidate variants was assessed. AlphaFold3 and PyMOL software were used for homology modeling of the FBN1 protein and analysis of its three-dimensional structure and amino acid sequence conservation. This study was approved by the Medical Ethics Committee of Taizhou Enze Medical Center (Group) (Ethics No. 20231002).
RESULTS:
Cardiovascular system abnormalities were noted in all pedigrees, ocular abnormalities were present in pedigrees 2 and 5, skeletal system abnormalities were presented in pedigrees 1, and 4 to 6. FBN1 gene mutations were identified in all pedigrees, including c.1957_1958dupGT (p.Asp654fs), c.5014T>A (p.Cys1672Ser), c.8135delC (p.Pro2712fs), c.2302G>T (p.Glu768*), c.3473A>G (p.Glu1158Gly) and c.6169C>T (p.Arg2057*), with each involving a different exon. Four variants were rated as pathogenic, one as likely pathogenic, and one as variant of uncertain significance. Among these, c.5014T>A (p.Cys1672Ser), c.1957_1958dupGT (p.Asp654fs), c.8135delC (p.Pro2712fs), and c.2302G>T (p.Glu768*) were unreported previously. Bioinformatic analysis with SIFT and PolyPhen-2 predicted that the c.5014T>A (p.Cys1672Ser) and c.3473A>G (p.Glu1158Gly) variants were deleterious. Protein homologous sequence alignment analysis revealed that the four novel mutation sites are highly conserved across various species. Homology modeling of the FBN1 protein three-dimensional structure indicated that the six variant sites in the amino acid sequence are all close to hydrogen bonds and may alter the secondary and tertiary structures to varying degrees, thereby confirmed the relationship between the variants and MFS.
CONCLUSION
Four novel variants of the FBN1 gene have been discovered in this study, which has enriched the mutational and phenotypic spectrum of MFS and provided a basis for disease diagnosis and genetic counseling.
Adolescent
;
Adult
;
Child
;
Female
;
Humans
;
Male
;
Middle Aged
;
Young Adult
;
China
;
East Asian People/genetics*
;
Exome Sequencing
;
Fibrillin-1/genetics*
;
Marfan Syndrome/genetics*
;
Mutation
;
Pedigree
;
Retrospective Studies
;
Adipokines
8.Genetic re-analysis of a Chinese pedigree affected with Hypertrophic cardiomyopathy due to a heterozygous truncating variant of ALPK3 gene and literature review.
Chenliang HONG ; Xianhong DING ; Yang LU ; Jia ZHU ; Jinwei WANG ; Mengyi XU ; Shuaishuai CHEN ; Bo SHEN ; Weili GE
Chinese Journal of Medical Genetics 2025;42(11):1337-1346
OBJECTIVE:
To explore the clinical and genetic characteristics of a Chinese pedigree affected with Hypertrophic cardiomyopathy (HCM) due to a truncating variant of ALPK3 gene.
METHODS:
A 44-year-old male admitted to Taizhou Hospital of Zhejiang Province on December 29, 2018 was selected as the study subject. Whole-exome sequencing (WES) was carried out, and candidate variant was interpreted by following the guidelines from the American College of Medical Genetics and Genomics (ACMG). For ALPK3 was considered an autosomal recessive gene, the WES results was considered insufficient to explain his phenotype. In April 2023, the proband's WES data were re-analyzed using updated annotation pipelines, and peripheral blood samples were collected from his first-degree relatives (mother and brother) for Sanger sequencing validation. Conservation analysis and protein structural modeling were performed to assess the impact of the variant. Clinical evaluation and genetic counseling were provided to the proband's family members. Relevant literature on ALPK3tv-induced HCM patients were searched in Wanfang Data Knowledge Service Platform, CNKI, and PubMed database using "ALPK3" and "hypertrophic cardiomyopathy" as keywords. Clinical characteristics of HCM patients with heterozygous ALPK3tv variants were summarized and compared with the clinical characteristics of HCM patients with positive sarcomere-associated gene variants (SARC+). This study was approved by the Medical Ethics Committee of Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University (Ethics No.: K20230314).
RESULTS:
The proband was a 44-year-old male who was transferred to our institution on December 29, 2018 due to "chest tightness and pain for 6 months, exacerbated for 2 days". Emergency coronary angiography was performed, which led to a preliminary diagnosis of "acute coronary syndrome", and the patient was admitted to the Cardiology Department for treatment. Based on electrocardiogram and echocardiogram findings, the diagnosis was revised as HCM. The patient's condition has stabilized post-coronary angiography, and he was discharged with improved condition. On January 2019, WES was conducted to determine the etiology of the proband's HCM. WES results identified a novel heterozygous c.2156dupC (p.Pro720ThrfsTer53) truncating variant in the ALPK3 gene. At that time, the inheritance pattern could not explain the phenotype. In 2022, a literature indicated that heterozygous ALPK3tv could lead to autosomal dominant HCM. Consequently, in April 2023, the proband's whole-exome data were re-annotated, revealing changes in the transcript and protein versions, with the updated site annotated as ALPK3 (NM_020778.5): c.1550dupC (p.Pro518ThrfsTer53). Sanger sequencing confirmed that the proband's mother and brother also carried this variant. The mother exhibited obstructive HCM, while the brother showed no related phenotype. Bioinformatics analysis demonstrated conservation of this site across multiple species, and the variant has resulted in the loss of a protein domain. Based on ACMG guidelines, the variant was classified as likely pathogenic. Literature review and Bayesian calculation further elevated the pathogenicity rating, indicating that this variant was the cause of HCM in the patient. Literature study revealed distinctions between HCM caused by this variant type and SARC+ HCM. The age of onset among heterozygous ALPK3tv patients was delayed by approximately 10 years compared to SARC+ patients. Both forms of HCM exhibited a male predominance, which was particularly marked in individuals with ALPK3tv. Electrocardiographic left ventricular hypertrophy was more prevalent in heterozygous ALPK3tv patients than in SARC+ patients. The incidence of apical or concentric hypertrophy patterns was higher in heterozygous ALPK3tv patients compared to asymmetric septal hypertrophy, which predominated in SARC+ patients. ALPK3tv patients exhibited lower penetrance and later onset compared to SARC+ patients. A positive correlation between left ventricular wall thickness and age was noted in female patients only.
CONCLUSION
In this pedigree, the proband has presented with HCM, characterized by echocardiographic evidence of apical left ventricular hypertrophy without significant outflow tract obstruction or extracardiac phenotypes. Although his mother and brother had carried the same heterozygous ALPK3 (NM_020778.5) c.1550dupC (p.Pro518ThrfsTer53), the mother exhibited severe obstructive HCM, while the brother was asymptomatic, suggesting incomplete or age-dependent penetrance within the family. This study has enriched the evidence for the pathogenicity of ALPK3tv among Chinese HCM pedigrees and underscored the importance of periodic literature reviews and genetic re-analysis for unresolved genetic testing results.
Humans
;
Male
;
Pedigree
;
Adult
;
Cardiomyopathy, Hypertrophic/genetics*
;
Heterozygote
;
Asian People/genetics*
;
Exome Sequencing
;
Mutation
;
China
;
Female
;
East Asian People
9.Research on the relations of intraventricular pressure gradients determined by echocardiography and left ventricular cardiotoxicity in the early stage of anthracycline chemotherapy
Mengxiao HAN ; Jian ZHANG ; Manchen YANG ; Qunling ZHANG ; Xianhong SHU ; Zheng LI ; Leilei CHENG
Chinese Journal of Cardiology 2025;53(8):891-897
Objective:To preliminarily explore the relationship between intraventricular pressure gradients (IVPG) measured by ultrasound hemodynamic analysis and left ventricular cardiotoxicity after anthracycline chemotherapy.Methods:This was a retrospective cohort study. Patients with diffuse large B-cell lymphoma (DLBCL) who completed 6 cycles of R-CHOP chemotherapy at Fudan University Shanghai Cancer Center from 2014 to 2015 were included. Echocardiography was performed at baseline (T0), after 2 cycles of chemotherapy (T1), after 4 cycles of chemotherapy (T2), and after all chemotherapy cycles (T3). Left ventricular global longitudinal strain (LVGLS), left ventricular global circumferential strain (LVGCS), and left ventricular ejection fraction (LVEF) were analyzed using speckle-tracking imaging technology, and IVPG was measured using hemodynamic analysis technology, including IVPG of long-axis (IVPG-LA) and IVPG of short-axis. The change rate of each index from T0 to T2 was marked as Δ. Left ventricular cardiotoxicity was defined as a decrease in LVEF of ≥10% from the baseline level or LVEF ≤50%. Univariate logistic regression analysis was used to explore the related factors of left ventricular myocardial toxicity, and the receiver operating characteristic curve was drawn to analyze their evaluation efficiency for left ventricular myocardial toxicity.Results:A total of 55 patients were included, including 28 males (51%), aged (46.5±11.7) years. Twelve patients (22%) developed left ventricular cardiotoxicity. Compared with T0, IVPG-LA decreased at T1 ((10.73±2.51)% vs. (11.52±3.62)%, P=0.037); while LVGLS, LVGCS, and LVEF only decreased at T3 (all P<0.05). Univariate logistic regression analysis showed that ΔIVPG-LA and ΔLVGLS were related factors for left ventricular myocardial toxicity in patients with DLBCL receiving chemotherapy (all P<0.05). The receiver operating characteristic curve showed that the area under the curve of ΔLVGLS was 0.702, with an optimal cut-off value of 13.15% (sensitivity 66.7%, specificity 62.8%); the area under the curve of ΔIVPG-LA was 0.812, with an optimal cut-off value of 20.74% (sensitivity 75.0%, specificity 90.7%). Conclusions:Hemodynamic analysis technology shows promise clinical application value in evaluating subclinical changes in left ventricular function in tumor patients after anthracycline chemotherapy; the change rate of IVPG-LA could be used as an early indicator of left ventricular toxicity after anthracycline chemotherapy.
10.A Geant4-based research on radiation field distribution in a 9 MeV e-FLASH treatment room
Deqi CHENG ; Qin YANG ; Xufan HUANG ; Peng WU ; Haoran XIE ; Jing XIA ; Erfeng WANG ; Guofu YU ; Yu JIANG ; Xianhong LIU
Chinese Journal of Radiological Medicine and Protection 2025;45(11):1152-1156
Objective:To investigate the radiation field distribution characteristics in a 9 MeV electron FLASH (e-FLASH) linear accelerator treatment room.Methods:The Geant4 Monte Carlo program was employed for physical simulating of the radiation field distribution inside and outside the treatment room under a single-beam delivery condition with a total dose of 50 Gy at the reference point and a dose rate of 250 Gy/s. High-sensitivity radiation detectors (AT1123) were used to validate the measurements at key points.Results:The dose rate at the reference point was approximately 9×10 11 μSv/h. Due to the scattering and shielding effects, the deviation of the attenuation rate from the inverse-square law was observed and the isodose lines exhibited spatial drift. Measured dose rates at key points showed good agreement with the simulation result, with a maximum deviation within 30%. Conclusions:The complex radiation field distribution can be effectively simulated using Geant4 in an e-FLASH treatment room. This indicated the Geant4 is not only applicable for the shielding calculations in e-FLASH radiotherapy facilities, but also for the design optimization through, reduction of trial-and-error iterations and engineering costs.

Result Analysis
Print
Save
E-mail