1.Assessing High-density Y-SNP Panels for Paternal Haplogroup Assignment in Forensic Practice
De-Qin ZHANG ; Chun-Nian WANG ; Lin-Lin LOU ; Meng NI ; Jing GAO ; Jiang HUANG ; Li JIANG
Progress in Biochemistry and Biophysics 2026;53(2):458-469
ObjectiveThe accuracy of Y-chromosome haplogroup assignment is crucial for tracing paternal lineage in male samples. With the advancement of high-throughput sequencing technologies, high-density Y-SNP genotyping from whole-genome or array-based data has become a standard method for determiningY-chromosome haplogroups. This study systematically evaluated the performance of 4 commonly used high-density SNP genotyping systems—namely, the Global Screening Array (GSA), Chinese Genotyping Array (CGA), Affymetrix array, and the 1240K capture panel—for haplogroup assignment. This work provides a reference for data comparison across different systems. MethodsWe extracted genotype data for the 4 Y-SNP panels from 30× whole-genome sequencing (WGS) data of 1 590 male samples from the 1000 Genomes Project. Additionally, GSA array genotype data from 384 relative pairs (spanning 1st- to 12th-degree relationships) from 109 Chinese Han families were collected. Haplogroup assignment was performed using Y-LineageTracker v1.3.0 software. We assessed the concordance and resolution of haplogroup assignments between the four Y-SNP panels and the WGS data. The consistency and resolution of haplogroup assignments were also evaluated for both the 1000 Genomes Project samples and the 109 family samples collected in this study. Furthermore, the impact of varying numbers of Y-SNPs on haplogroup assignment was examined. ResultsThe GSA and CGA panels demonstrated superior resolution and discrimination of haplogroup subclades compared with the other two panels. The haplogroup assignments from the GSA, CGA, and 1240K panels showed high concordance with WGS data, with consistency rates exceeding 88.70%, whereas the Affymetrix platform exhibited a significantly lower consistency rate of 61.89%. Specifically, the GSA and CGA panels consistently demonstrated superior performance compared with the other two panels in the assignment of haplogroups O-M175 and H-L901, achieving complete concordance (100%) for both haplogroups. In contrast, the Affymetrix panel erroneously assigned all individuals belonging to haplogroup O-M175 to haplogroup K2-M526. Furthermore, its accuracy for haplogroup H-L901 was exceedingly low, at merely 1.41%. This poor performance was characterized by the misassignment of 98.59% of H-L901 samples—specifically, 1.41% to J-M304 and a predominant 97.18% to F-M89. For haplogroup R-M207, all four panels exhibited uniformly high levels of consistency, with concordance values exceeding 94.00%. Notably, for haplogroup E-M96, the 1240K and Affymetrix panels outperformed the GSA and CGA panels in terms of concordance, representing the first instance in which these two panels surpassed the latter. Conversely, for haplogroups J-M304, Q-M242, and I-M170, all 4 panels showed relatively elevated misclassification rates, with the Affymetrix array demonstrating the poorest overall performance. None of the four panels showed any discordant haplogroup assignments among the familial relative pairs analyzed. A positive correlation was observed between the number of Y-SNPs (ranging from 1 000 to 10 000) and classification consistency; however, classification consistency plateaued when the number of Y-SNPs exceeded 10 000. Furthermore, a random sampling analysis conducted on the GSA and CGA panels demonstrated that the haplogroup misclassification rate exhibited negligible fluctuation across the Y-SNP range of 500 to 1 000. Conversely, a marked enhancement in classification consistency was observed as the number of markers increased from 1 000 to 5 000, ultimately reaching a plateau within the interval of 5 000 to 8 000 markers. ConclusionThese findings indicate that the GSA and CGA panels provide high resolution and concordance, delivering reliable Y-haplogroup assignment for forensic investigations.
2.Assessing High-density Y-SNP Panels for Paternal Haplogroup Assignment in Forensic Practice
De-Qin ZHANG ; Chun-Nian WANG ; Lin-Lin LOU ; Meng NI ; Jing GAO ; Jiang HUANG ; Li JIANG
Progress in Biochemistry and Biophysics 2026;53(2):458-469
ObjectiveThe accuracy of Y-chromosome haplogroup assignment is crucial for tracing paternal lineage in male samples. With the advancement of high-throughput sequencing technologies, high-density Y-SNP genotyping from whole-genome or array-based data has become a standard method for determiningY-chromosome haplogroups. This study systematically evaluated the performance of 4 commonly used high-density SNP genotyping systems—namely, the Global Screening Array (GSA), Chinese Genotyping Array (CGA), Affymetrix array, and the 1240K capture panel—for haplogroup assignment. This work provides a reference for data comparison across different systems. MethodsWe extracted genotype data for the 4 Y-SNP panels from 30× whole-genome sequencing (WGS) data of 1 590 male samples from the 1000 Genomes Project. Additionally, GSA array genotype data from 384 relative pairs (spanning 1st- to 12th-degree relationships) from 109 Chinese Han families were collected. Haplogroup assignment was performed using Y-LineageTracker v1.3.0 software. We assessed the concordance and resolution of haplogroup assignments between the four Y-SNP panels and the WGS data. The consistency and resolution of haplogroup assignments were also evaluated for both the 1000 Genomes Project samples and the 109 family samples collected in this study. Furthermore, the impact of varying numbers of Y-SNPs on haplogroup assignment was examined. ResultsThe GSA and CGA panels demonstrated superior resolution and discrimination of haplogroup subclades compared with the other two panels. The haplogroup assignments from the GSA, CGA, and 1240K panels showed high concordance with WGS data, with consistency rates exceeding 88.70%, whereas the Affymetrix platform exhibited a significantly lower consistency rate of 61.89%. Specifically, the GSA and CGA panels consistently demonstrated superior performance compared with the other two panels in the assignment of haplogroups O-M175 and H-L901, achieving complete concordance (100%) for both haplogroups. In contrast, the Affymetrix panel erroneously assigned all individuals belonging to haplogroup O-M175 to haplogroup K2-M526. Furthermore, its accuracy for haplogroup H-L901 was exceedingly low, at merely 1.41%. This poor performance was characterized by the misassignment of 98.59% of H-L901 samples—specifically, 1.41% to J-M304 and a predominant 97.18% to F-M89. For haplogroup R-M207, all four panels exhibited uniformly high levels of consistency, with concordance values exceeding 94.00%. Notably, for haplogroup E-M96, the 1240K and Affymetrix panels outperformed the GSA and CGA panels in terms of concordance, representing the first instance in which these two panels surpassed the latter. Conversely, for haplogroups J-M304, Q-M242, and I-M170, all 4 panels showed relatively elevated misclassification rates, with the Affymetrix array demonstrating the poorest overall performance. None of the four panels showed any discordant haplogroup assignments among the familial relative pairs analyzed. A positive correlation was observed between the number of Y-SNPs (ranging from 1 000 to 10 000) and classification consistency; however, classification consistency plateaued when the number of Y-SNPs exceeded 10 000. Furthermore, a random sampling analysis conducted on the GSA and CGA panels demonstrated that the haplogroup misclassification rate exhibited negligible fluctuation across the Y-SNP range of 500 to 1 000. Conversely, a marked enhancement in classification consistency was observed as the number of markers increased from 1 000 to 5 000, ultimately reaching a plateau within the interval of 5 000 to 8 000 markers. ConclusionThese findings indicate that the GSA and CGA panels provide high resolution and concordance, delivering reliable Y-haplogroup assignment for forensic investigations.
3.Development and Validation of a High-Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Detecting Adrenocortical Hormones and Establishment of Age-Stratified Reference Intervals in Reproductive-Aged Women from Guangxi, China
Yixuan LIU ; Tingwei JIN ; Yushuang WEI ; Xuelian QIN ; Siyu DENG ; Jie ZHENG ; Boteng YAN ; Yuanyuan NONG ; Yu YE ; Shengzhu HUANG ; Yu LONG ; Jianmin LI ; Ganqin WANG ; Pei HUANG ; Jinghang JIANG ; Fan WU ; Zengnan MO ; Yonghua JIANG
Annals of Laboratory Medicine 2026;46(2):146-154
Background:
Adrenocortical hormones, particularly 11-oxygenated androgens, are pivotal in female reproductive health and fertility. Standardized detection kits and population-specific reference intervals are lacking in China, hindering related clinical applications.
Methods:
A HPLC-tandem mass spectrometry (HPLC-MS/MS) pipeline was developed, rigorously validated, and applied to simultaneously quantify corticosterone, cortisone, cortisol, 18-OH cortisol, androstenedione (A4), 11β-hydroxyandrostenedione (11-OH A4), dehydroepiandrosterone, and dehydroepiandrosterone sulfate in serum samples from 455 reproductive-aged women (18–45 yrs) in Guangxi, China. Age-dependent concentration trends were analyzed, and reference intervals stratified by age (2.5th to 97.5th percentiles) were established. Correlations with body-composition metrics, ethnicity, and the menstrual cycle were investigated.
Results:
The HPLC-MS/MS method demonstrated high precision (intra- and inter-assay CVs < 15%), accuracy, and sensitivity. All eight hormones exhibited significant age-related declines (P < 0.001 for seven hormones; P = 0.001 for 11-OH A4). Notably, 11-OH A4 levels were significantly lower in the 35–45-yr (3.05 nmol/L) and 25–34-yr (3.09 nmol/L) age groups than in the 18–24-yr (3.57 nmol/L) age group, whereas no significant difference was observed between the 35–45-yr and 25–34-yr age groups. Weak negative correlations were observed between the body mass index and corticosterone and cortisone levels, whereas ethnicity and the menstrual cycle showed no significant associations with hormone levels.
Conclusions
We developed an HPLC-MS/MS-based method for simultaneously quantifying eight adrenocortical hormones, including 11-OH A4, and defined age-specific reference intervals for reproductive-aged Chinese women. These findings advance the clinical utility of adrenocortical hormones in diagnosing and managing reproductive disorders.
4.Consistent Detection of Aquaporin-4 Antibodies:A Comparative Analysis Between Fixed and Live Cell-Based Assays
Jing WANG ; Linge WANG ; Xiaolin YANG ; Zhizhong LI ; Jinyu JIANG ; Qiao XU ; Siyuan HUANG ; Qing FU ; Yang YANG ; Rongrong ZHANG ; Lin YANG ; Ai CHEN ; Xiaopeng ZENG ; Ke XU ; Peng ZHENG ; Xinyue QIN ; Jinzhou FENG
Journal of Clinical Neurology 2026;22(2):212-220
Background:
and Purpose Live cell-based assays (LCBA) are increasingly used for serological antibody detection due to their ability to preserve antigen conformation, offering moderately higher sensitivity than fixed cell-based assays. However, the clinical necessity of prioritizing LCBA for the detection of aquaporin-4 immunoglobulin G (AQP4-IgG) in neuromyelitis optica spectrum disorder (NMOSD) remains unclear, especially when compared to its established role in diagnosing myelin oligodendrocyte glycoprotein antibody-associated disease.
Methods:
We compared the performance of live cell-based assays using immunofluorescence (LCBA-IF) and fixed cell-based assays using immunofluorescence (FCBA-IF) in detecting AQP4-IgG in 90 cases of NMOSD meeting 2015 International Panel for Neuromyelitis Optica Diagnosis criteria, alongside 40 controls. Additionally, we further investigated the relationship between AQP4-IgG titers as measured by LCBA-IF and FCBA-IF and clinical parameters in NMOSD patients.
Results:
Results showed 96.9% agreement between LCBA-IF and FCBA-IF (Cohen’s κ=0.935), with a strong Spearman correlation (0.977, p<0.001). Both methods demonstrated 100% specificity, with LCBA-IF showing slightly higher sensitivity compared to FCBA-IF. Within LCBAIF-tested groups, statistically significant differences in annualized relapse rates were observed across all pairwise comparisons (low-titer vs. moderate-titer, low-titer vs. high-titer, and moderate-titer vs. high-titer; all p<0.050). However, this association reached statistical significance in some FCBA-IF-tested groups.
Conclusions
Overall, there is a strong concordance between LCBA-IF and FCBA-IF in detecting AQP4-IgG, where LCBA-IF shows slightly higher sensitivity. Furthermore, there is a potential link between elevated AQP4-IgG titers and an increased risk of relapse, and this correlation may appear more pronounced when using LCBA-IF.
5.0.05% Cyclosporine A combined with Olopatadine eye drops for the treatment of allergic conjunctivitis-related dry eye disease
Jinfen LI ; Yue LI ; Hui HUANG ; Qianqian LAN ; Zhou ZHOU ; Wenjing HE ; Yuanjun QIN ; Li JIANG ; Fan XU
International Eye Science 2025;25(7):1152-1159
AIM: To explore the efficacy of 0.05% cyclosporine A combined with olopatadine eye drops in treating allergic conjunctivitis-related dry eye disease.METHODS: A total of 63 patients(63 eyes)with allergic conjunctivitis-related dry eye disease in the People's Hospital of Guangxi Zhuang Autonomous Region from August 2022 to April 2023 were enrolled and randomly divided into control group(n=33)and observation group(n=30). The patients of the control group were administrated with 0.1% olopatadine eye drops and 0.3% sodium hyaluronate eye drops, while the observation group was administrated with 0.1% olopatadine eye drops and 0.05% cyclosporine A eye drops. The ocular surface disease index(OSDI), total ocular symptom score(TOSS), conjunctival congestion score, conjunctival papillae and follicle score, Schirmer I test(SⅠt), tear meniscus height(TMH), meibomian gland secretion ability and property score, meibomian gland loss area score, corneal fluorescein staining(CFS), tear film break-up time(BUT), noninvasive first tear film break-up time(NIBUTf), noninvasive average tear film break-up time(NIBUTav)before and after treatment and the drug safety during the treatment period of both groups of patients were evaluated.RESULTS: After treatment, OSDI, TOSS, conjunctival congestion score, conjunctival papillae and follicle score, SⅠt, TMH, meibomian gland secretion ability score and property score, CFS, BUT, NIBUTf, and NIBUTav of the observation group showed improvements compared with those before treatment(all P<0.017). Among these, OSDI, TOSS, conjunctival congestion score, conjunctival papillae and follicle score, BUT, NIBUTf, and NIBUTav demonstrated significant improvement compared with the control group(all P<0.05). There was no statistically significant difference in meibomian gland loss area score between the two groups before and after treatment(P>0.05). During the treatment period, there were no local or systemic adverse reactions.CONCLUSION: The combined use of 0.05% cyclosporine A and olopatadine eye drops can significantly improve ocular discomfort symptoms of patients with dry eye disease associated with allergic conjunctivitis, such as red eyes, itchy eyes and foreign body sensation, promote tear film stability and have high safety.
6.Inhibitory effect of gallic acid on HCC1806 triple-negative breast cancer xenograft growth in nude mice
Chun-juan JIANG ; Si LIN ; Hui-zhen QIN ; Jie HUANG
Chinese Traditional Patent Medicine 2025;47(6):1853-1860
AIM To investigate the inhibitory effect of gallic acid on HCC1806 triple-negative breast cancer xenograft growth in nude mice.METHODS The nude mouse models of HCC1806 triple-negative breast cancer xenograft growth were established and randomly divided into the model group,the gallic acid group(200 mg/kg)and the adriamycin group(5 mg/kg),with 6 mice in each group.After 21 days of respective drug administration,the nude mice were killed and had their xenografts procured and measured.The nude mice had their serum levels of IL-6 and TNF-α detected by ELISA;their morphological changes of xenografts observed with HE staining;their protein expressions of p53,PCNA and Ki67 in xenograft detected by immunohistochemistry;their mRNA expressions of PCNA,Ki67,Bcl-2,Bax,Caspase-3,PI3K,Akt,JNK and p38 detected by RT-qPCR;and their protein expressions of Bcl-2,Bax,Caspase-3,cleaved-Caspase-3,PI3K,p-PI3K,Akt,p-Akt,JNK,p-JNK,p38 MAPK and p-p38 MAPK in xenografts detected by Western blot.RESULTS Compared with the model group,the groups intervened with either gallic acid or adriamycin shared decreased tumor weight(P<0.05);increased serum levels of IL-6 and TNF-α(P<0.05,P<0.01);condensed or irregular nuclei of xenograft,and increased number of cell necrosis;increased protein expressions of p53 and Bax and the ratios of cleaved-Caspase-3/Caspase-3,p-JNK/JNK and p-p38/p38 in xenograft(P<0.01);decreased protein expressions of PCNA,Ki67 and Bcl-2 and the ratios of p-PI3K/PI3K and p-Akt/Akt(P<0.01);decreased mRNA expressions of PCNA,Ki67,Bcl-2,PI3K and Akt(P<0.05,P<0.01);and increased mRNA expressions of Caspase-3,Bax,JNK and p38(P<0.05,P<0.01).CONCLUSION Gallic acid can inhibit HCC1806 triple-negative breast cancer xenograft growth in nude mice,and the underlying mechanism may involve suppression of pro-cell proliferation proteins,activation of pro-apoptotic proteins,and modulation of the PI3K/Akt and JNK/p38 signaling pathways.
7.Discussion on curative effect of electronic bronchoscope in treating tracheobronchial tuberculosis at clinical activity stage
Shenglin MO ; Yun HUANG ; Xiaohong HUANG ; Gui TANG ; Yanping SUN ; Jinyu QIN ; Tao CHEN ; Jiaguang HU ; Peng ZHANG ; Jinliang KONG ; Zhongsheng JIANG
China Medical Equipment 2025;22(6):76-80
Objective:To evaluate the clinically curative effect of intervention treatment of electronic bronchoscope in treating tracheobronchial tuberculosis at clinical activity stage.Methods:Sixty patients with tracheobronchial tuberculosis at clinical activity stage(type I,II,III and VI)who admitted to Liuzhou People's Hospital from September 2020 to September 2023 were selected,and they were divided into drug group(anti-tuberculosis drug treatment)and combination group(anti-tuberculosis drug treatment+interventional treatment with electronic bronchoscope)by the random number table method,with 30 cases in each group.The curative effects of the two groups were observed,and the negative conversion rate of sputum bacteria,clinical symptom scores(cough symptom,expectoration symptom)before and after treatment,Modified British Medical Research Council Dyspnea Scale(mMRC)score between two groups were compared,and the differences in indicators of pulmonary function such as forced expiratory volume in the first second(FEV1),forced vital capacity(FVC)and maximum voluntary ventilation(MVV)between the two groups also were compared.And then,the incidence of complications was calculated.Results:During the 1,2 and 3 months of follow-up,there were respectively 21 cases,27 cases and 30 cases occurred negative conversion of sputum bacteria in 30 patients of the combination group,and there were respectively 15 cases,18 cases and 23 cases occurred negative conversion of sputum bacteria in 30 patients of the drug group.At the 1st month of follow-up,the negative conversion rate of sputum bacteria in combination group was higher than that in drug group,while there was no statistically significant difference between the two groups(P>0.05).At the 2nd and 3rd month of follow-up,the negative conversion rate of sputum bacteria in the combination group was higher than that in the drug group,and the differences were statistically significant(x2=7.200,7.925,P<0.05).The effective rate of treatment of the combination group was 100%,which was higher than 80%of the drug group,and the difference of that between two groups was significant(x2=6.667,P<0.05).After 2 months of treatment,the mMRC score,cough symptom score and expectoration symptom score of the combination group were all lower than those of the drug group,and the differences were statistically significant(t=3.504,3.950,3.530,P<0.05).The improvement effects of FEV1,FVC and MVV of the combination group were all better than those of the drug group,and the differences were statistically significant(t=6.626,4.966,4.097,P<0.05).There was no significant difference in the incidence of complications between the two groups(P>0.05).Conclusion:Anti-tuberculosis drug therapy combined with electronic bronchoscopy intervention has a good therapeutic effect in clinically active tracheobronchial tuberculosis.
8.Exploring aspirin discontinuation timing based on third-trimester risk reassessment in women with first-trimester high risk of pre-eclampsia
Xiaoyan HUANG ; Meiqin JIANG ; Qianqian LIN ; Wenjing MENG ; Qin XUE
Chinese Journal of Obstetrics and Gynecology 2025;60(9):709-715
Objective:To investigate whether continued low-dose aspirin (LDA) intervention affects the incidence of pre-eclampsia (PE) and adverse pregnancy outcomes in pregnant women with high-risk PE screening in the first trimester and reassessed as low risk at 28 weeks of gestation.Methods:This study was a prospective observational cohort study. From April 2022 to April 2024, a total of 106 pregnant women who underwent prenatal examination in the Affiliated Jiangyin Hospital of Nantong University were enrolled. They were assessed as high risk of PE by multiple indicators combined screening at 11-13 +6 weeks of gestation, received LDA intervention, and were reassessed as low risk of PE at 28 weeks of gestation. The patients were divided into withdrawal group (49 cases) and continuation group (57 cases). The incidence of PE and adverse pregnancy outcomes were compared between the two groups. Results:(1) There were no statistically significant differences in general conditions and the incidence of pregnancy complications between the two groups (all P>0.05). During the PE risk screening at 11-13 +6 weeks of gestation, there were no statistically significant differences in mean arterial pressure (MAP) and ultrasound uterine artery pulsation index (UtPI) between the two groups (all P>0.05), but the placental growth factor (PlGF) level in the withdrawal group was significantly lower than that in the continuation group ( P=0.023). There was no significant difference in the proportion of pregnant women with high risk of PE before 32 weeks and 34 weeks of pregnancy between the two groups (all P>0.05). (2) There were 7 cases (14%, 7/49) of PE in the withdrawal group, including 1 case (2%, 1/49) of early-onset PE and 3 cases (6%, 3/49) of PE before 37 weeks of pregnancy. There were 11 cases (19%, 11/57) of PE in the continuation group, including 2 cases (4%, 2/57) of early-onset PE and 4 cases (7%, 4/57) of PE before 37 weeks of pregnancy. There were no significant differences in the incidence of PE (including early-onset PE and PE before 37 weeks of pregnancy), gestational hypertension, severe PE, chronic hypertension complicated with PE and chronic hypertension complicated with pregnancy between the two groups (all P>0.05). (3) There were no significant differences in cesarean section rate, preterm birth rate, placental abruption, postpartum hemorrhage, fetal growth restriction, fetal distress rate, neonatal birth weight, neonatal asphyxia, and 1-minute and 5-minute Apgar scores between the two groups (all P>0.05). No stillbirth occurred in the two groups. Conclusion:For pregnant women with high risk of PE screening in the first trimester and taking LDA intervention, there is no difference in the incidence of PE and adverse pregnancy outcomes whether to continue LDA or not after being reassessed as low risk at 28 weeks of gestation.
9.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.
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.

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