Objective: With the development of global nuclear power, the discharge of tritium during nuclear power plant operation has raised concerns. This study provides basic data support for the assessment of tritium radioactivity levels in seawater and seafood around nuclear power plants. Methods: This study selected the coastal waters near a nuclear power plant in China as the research area. A total of 15 surface seawater samples and three types of marine organisms (laver, oyster, and mullet) were collected to measure and analyze the tritium activity concentrations in seawater and marine organisms. Results: The tritium activity concentrations in seawater ranged from 1.54 to 3.55 Bq/L, with an average of 2.25 ± 0.70 Bq/L. In marine organisms, the tritium activity concentrations ranged from 1.1 to 1.6 Bq/L. The total dose rates of tritium to mullet and oyster were 6.93 × 10−7 μGy/h and 5.39 × 10−7 μGy/h, respectively. Conclusion: Compared with tritium activity concentrations in adjacent waters, those in seawater near this nuclear power plant showed no significant increases, and the tritium content in marine organisms remained within normal ranges. The radiation doses of tritium in mullet and oyster did not pose a radiation hazard to these two organisms.
Objective: To compare the differences in intraoperative radiation exposure between leadless and transvenous pacemaker implantation. Methods: Cumulative dose (CD), dose area product (DAP), and fluoroscopy time during procedure were recorded and analyzed in 21 patients with leadless pacemaker implantation (Micra group), 55 patients with transvenous single-chamber pacemaker implantation (VVI group), and 216 patients with transvenous dual-chamber pacemaker implantation (DDD group). Results: The fluoroscopy times of the Micra group, VVI group, and DDD group were 5.0 ± 1.9, 4.8 ± 1.4, and 7.6 ± 1.9 min, respectively (P < 0.001). Their CD values were 203.5 ± 76.1, 147.0 ± 41.0, and 249.6 ± 58.2 mGy, respectively (P < 0.001). Their DAP values were 18.6 ± 7.1, 13.4 ± 3.9, and 22.6 ± 5.6 Gy·cm2, respectively (P < 0.001). Compared with the VVI group, the Micra group had similar fluoroscopy time (P=0.813) but higher CD (P=0.010) and DAP values (P = 0.012). Compared with the DDD group, the Micra group had reduced fluoroscopy time (P < 0.001), CD value (P = 0.033), and DAP value (P = 0.047). Conclusion: Leadless pacemaker implantation is associated with increased radiation exposure compared to transvenous single-chamber pacemaker implantation. However, it offers a significant advantage in reducing radiation exposure for both medical staff and patients compared to transvenous dual-chamber pacemaker implantation.
Objective: To investigate the diagnostic value of color Doppler ultrasound of neck vessels combined with head and neck CT angiography (CTA) in detecting carotid artery stenosis among patients with stroke. Methods: A total of 104 patients with stroke admitted to the hospital between January 2023 and November 2024 were enrolled. All patients underwent color Doppler ultrasound of neck vessels and head and neck CTA, with digital subtraction angiography (DSA) used as the gold standard. Receiver operating characteristic (ROC) curves were plotted to analyze the diagnostic performance of each modality alone and in combination for detecting carotid artery stenosis in patients with stroke. Results: According to the DSA results, among the 104 patients, 7 were normal, while 47, 16, 25, and 9 cases showed mild, moderate, and severe stenosis and occlusion, respectively. Color Doppler ultrasound results showed 6 normal cases, and 45, 20, 23, and 10 cases of mild, moderate, and severe stenosis and occlusion, respectively. Using DSA as the gold standard, the sensitivity, specificity and kappa value for diagnosing carotid artery stenosis were 98.97%, 85.71% and 0.848, respectively. Head and neck CTA results showed 5 normal cases, and 47, 19, 22, and 9 cases of mild, moderate, and severe stenosis and occlusion, respectively. The sensitivity, specificity and kappa value of head and neck CTA for diagnosing carotid artery stenosis were 100.00%, 71.43% and 0.823, respectively. The combined examination results showed that among the 104 patients, there were 7 normal cases, and 46, 18, 24, and 9 cases of mild, moderate, and severe stenosis and occlusion, respectively. The sensitivity, specificity and kappa value of the combined diagnosis were 100.00%, 100.00% and 1.000, respectively. In the ROC analysis, the areas under the curves of color Doppler ultrasound, head and neck CTA, and the combined method were 0.968, 0.934, and 1.000, respectively, with no significant difference among the three ROC curves (Z = 1.017, 0.994, 1.527, respectively, P = 0.309, 0.320, 0.167, respectively). Conclusion: Color Doppler ultrasound of neck vessels combined with head and neck CTA shows good consistency with DSA in diagnosing carotid artery stenosis and its severity among patients with stroke. This combined method demonstrates high diagnostic performance, making it worthy of clinical application and promotion.
Objective: To analyze the effects of occupational exposure to high-frequency electromagnetic fields (HF-EMF) on female reproductive health, endocrine and neurobehavioral functions, and to provide a basis for conducting occupational health risk assessment and formulating targeted protection strategies. Methods: From February 2023 to February 2025, 120 female employees from the communication, medical, and electronic manufacturing industries in a region were selected as the exposure group. Concurrently, 100 female office employees without occupational exposure to HF-EMF were selected as the control group. Their demographic characteristics and reproductive health status were collected through questionnaire surveys. Electrochemiluminescence immunoassay was used to detect endocrine hormone levels, including follicle stimulating hormone, luteinizing hormone, estradiol, progesterone, and prolactin. The World Health Organization Neurobehavioral Core Test Battery was used to measure neurobehavioral function. Results: The rates of abnormal menstrual cycles, abnormal menstrual flow, spontaneous abortion, and preterm delivery in the exposure group were higher than those in the control group, with statistically significant differences (P < 0.05). Luteinizing hormone level of the exposure group in the follicular phase was lower than that of the control group, and the difference was statistically significant (P < 0.05). Estradiol level of the exposure group in the follicular phase was also lower than that of the control group, but the difference was not statistically significant (P > 0.05). The scores of tension-anxiety, depression-dejection, rage-hostility, fatigue-inertia, and confusion-bewilderment in the emotional states of the exposure group were higher than those of the control group, while the scores of vigor-activity and digit-symbol coding were lower than those of the control group, with statistically significant differences (P < 0.05). Conclusion: Occupational exposure to HF-EMF has adverse effects on female reproductive health, endocrine, and neurobehavioral function. Health protection measures for occupational exposure to HF-EMF should be strengthened to ensure the reproductive and mental health of the female occupational population.
Objective: To investigate the levels of gross α and gross β activities in different water types within a 40-kilometer radius around the Zhangzhou Nuclear Power Plant prior to its operation. Methods: In 2018, drinking water samples were collected from the area surrounding the nuclear power plant during both the wet and dry seasons, including source water, treated water, tap water, and well water. The gross α and gross β activity concentrations were measured using a low-background α/β counter, followed by statistical analysis. Results: A total of 80 water samples from different sources around the Zhangzhou Nuclear Power Plant were collected. The average gross α and gross β activity concentrations during the wet season were (0.110 ± 0.036) Bq/L and (0.643 ± 0.028) Bq/L, respectively, while those during the dry season were (0.124 ± 0.032) Bq/L and (0.624 ± 0.026) Bq/L, respectively. There were no significant differences in the gross α and gross β activity concentrations between the wet and dry seasons for the overall sample set (P > 0.05). However, there were statistically significant differences in the gross α and gross β activity concentrations between the wet and dry seasons for source water and well water (Zwet = −2.005, −2.123; Zdry = −1.943, −3.090; P < 0.05). Conclusion: The radioactivity levels in different water types within various ranges around the Zhangzhou Nuclear Power Plant before its operation were determined. The measured activity concentrations were at the same level as those from previous investigations in other regions of Fujian Province.
Objective: To investigate the differences in radiation dose during chest CT examinations among children of different age groups and establish dose estimation regression models. Methods: Chest CT data from 135 children aged 4 to 15 years were retrospectively collected from the First Affiliated Hospital of Soochow University between January 2022 and December 2023. The children were divided into three age groups: 4-5 years, 6-10 years and 11-15 years. CT scanning parameters (tube voltage, tube current, scan range) and dosimetry parameters including volume CT dose index (CTDIvol) dose length product (DLP), and size-specific dose estimate (SSDE) were recorded. The Kruskal-Wallis test was used to compare intergroup differences. A Pearson correlation analysis was performed to assess the relationship between age and dose indicators. Both linear and nonlinear regression models were constructed. Results: Age showed a weak positive correlation with CTDIvol (r = 0.27), a moderate positive correlation with DLP (r = 0.60), and a moderate negative correlation with SSDE (r = −0.55). Linear regression analysis revealed that DLP increased with age (y = 117.85 + 9.81x, R2 = 0.36), while SSDE decreased with age (y = 12.4 − 0.18x, R2 = 0.32). Using orthogonal distance regression, the goodness-of-fit of the nonlinear models for DLP and SSDE significantly improved (R2 = 0.99 and 0.94, respectively). Conclusion: In pediatric chest CT dose assessment, CTDIvol underestimates radiation dose compared to SSDE and fails to account for patient body size. The dose estimation models constructed with orthogonal distance regression outperform those established using the least squares method, demonstrating higher fitting accuracy, and can serve as a reference for personalized dose management in pediatric CT examinations.
Objective: To track and evaluate the implementation and application of the occupational health standard Radiation shielding requirements for radiotherapy room—Part 4: Radiotherapy room of 252Cf neutron afterloading (GBZ/T 201.4-2015) by radiation health technical service agencies, medical institutions, health supervision agencies, and radiotherapy facility design units, and to provide a scientific basis for the further revision and implementation of this standard. Methods: Following the Guideline for health standards tracking evaluation (WS/T 536-2017) and the project implementation plan, relevant practitioners were randomly selected for a questionnaire survey. The survey primarily focused on their awareness, standard training, application, and revision suggestions of GBZ/T 201.4-2015. The results were summarized and analyzed. Results: A total of 168 evaluation questionnaires were collected from relevant practitioners in 28 provinces. Only 31.6% of the respondents reported being “well familiar” or “ familiar” with the standard, 27.4% of the respondents believed that the standard was widely used, and 45.2% of the respondents believed that the standard could meet the needs of their work. Only 14.9% of the respondents had received relevant training on the standard, more than half of the respondents had not applied the standard within the past 10 years, and 45.2% of the respondents believed that the standard "needs to be revised". Conclusion: Due to the small number of californium-252 neutron afterloading radiotherapy devices in operation on the market, the overall awareness of the standard is low, suggesting that relevant authorities need to strengthen training and publicity of the standard, and that certain sections of the standard need to be revised or merged.
Objective: To guide occupational health inspectors in accurately identifying the key points of law enforcement and case management during the supervision of occupational health technical service institutions, standardize the collection of evidence for illegal activities and the application of legal provisions, ensure the proper execution of administrative penalties, and provide insights for handling cases related to the supervision and law enforcement of occupational health technical services. Methods: This study analyzed the key points of evidence collection using an example case involving an entity that engaged in occupational health test and evaluation technical services without obtaining the required qualifications for occupational health technical service institutions. Results: The key points of evidence collection primarily included: evidence proving the qualification of the penalized subject, evidence proving jurisdictional authority, evidence proving the conduct of occupational health technical services, evidence proving the absence of an Occupational Health Technical Service Institution Qualification Certificate, evidence proving illegal gains, evidence proving the circumstances of the violation, and other evidence proving the legality of administrative procedures. Conclusion: In the implementation of administrative penalties by occupational health supervisors, standardized investigation and evidence collection constitute a critical component of law enforcement and case handling. Sufficient evidence collection and accurate application of the law are indispensable for safeguarding public health and societal interests against infringement.
Objective: To investigate the induction of senescence in L02 hepatocytes by low-dose fractionated X-ray radiation and its effects on oxidative stress, oxidative damage, and nuclear factor-κB (NF-κB) pathway protein levels. Methods: L02 cells were subjected to fractionated X-ray irradiation at doses of 0.1, 0.2, and 0.5 Gy per fraction for a total of six fractions. Assays were performed 24 hours after the final irradiation. Measurements included SA-β-gal staining, the mRNAs of senescence-related genes p53 and p21 and their encoded proteins, mRNAs of genes encoding senescence-associated secretory phenotype factors (IL-6, IL-8, GM-CSF, MMP-15), reactive oxygen species, oxidative and anti-oxidative markers (malondialdehyde, glutathione, superoxide dismutase), DNA oxidative damage markers (8-OHdG and γ-H2AX), and NF-κB pathway protein levels. Results: Compared with the control group, at 24 hours after the end of six irradiations, the number of cells positive in SA-β-gal staining was significantly increased in all dose groups. The mRNA and protein levels of p21 and p53 were significantly elevated in the 0.2 Gy × 6 and 0.5 Gy × 6 groups (P < 0.05). The mRNA levels of genes encoding IL-6, GM-CSF, and MMP-15 were significantly increased in all dose groups (P < 0.05). The mRNA levels of the gene encoding IL-8 were significantly increased in the 0.2 Gy × 6 and 0.5 Gy × 6 groups (P < 0.05). The levels of reactive oxygen species, malondialdehyde, and glutathione were significantly increased in all dose groups (P < 0.01). The level of superoxide dismutase was significantly increased in the 0.5 Gy × 6 group (P < 0.01). The levels of 8-OHdG were significantly increased in all dose groups (P < 0.05). In both the 0.2 Gy × 6 and 0.5 Gy × 6 groups, the expression levels of γ-H2AX and p-NF-κB p65 were significantly increased (P < 0.05), and the levels of IκBα were significantly decreased (P < 0.05). Conclusion: Low-dose fractionated X-ray radiation can induce senescence and cause alterations in oxidative stress, oxidative damage, and the levels of NF-κB pathway proteins in L02 hepatocytes.
Objective: To investigate the effects of whole breast combined with regional nodal hypofractionated radiotherapy compared with conventional fractionated radiotherapy on peripheral lymphocyte count (PLC) and neutrophil-to-lymphocyte ratio (NLR) in patients with breast cancer after breast-conserving surgery. Methods: This retrospective study enrolled 94 patients with breast cancer who underwent breast-conserving surgery in Tangshan People’s Hospital between April 2022 and April 2024. All patients received whole breast combined with regional nodal radiotherapy. These patients were divided into hypofractionated radiotherapy group (n = 42) and conventional fractionated radiotherapy group (n = 52) according to radiotherapy regimen. Differences in PLC and NLR before and after radiotherapy between the two groups were compared using the t-test. Results: Before radiotherapy, the baseline PLC and NLR were comparable between the two groups (P > 0.05). After radiotherapy, PLC decreased and NLR increased in both groups (P < 0.05). The PLC in the hypofractionated radiotherapy group was significantly higher than that in the conventional fractionated radiotherapy group (0.95 ± 0.30 vs. 0.77 ± 0.26, P = 0.002), and the NLR was significantly lower in the hypofractionated radiotherapy group than in the conventional fractionated radiotherapy group (2.86 ± 1.27 vs. 3.67 ± 1.59, P = 0.010). Conclusion: Compared with conventional fractionated radiotherapy, whole breast combined with regional nodal hypofractionated radiotherapy has less impact on PLC and NLR in patients with breast cancer after breast-conserving surgery.
Objective: To evaluate the influence of the wearing position of dosimeters outside lead aprons on effective dose estimation for interventional radiology workers, analyze the differences between single and double dosimeter methods in effective dose estimation, and provide a reference for the personal dose monitoring of interventional radiology workers. Methods: This study employed a combined approach of on-site monitoring and Monte Carlo simulation to evaluate the impact of the wearing position of dosimeters outside lead aprons on effective dose estimation, as well as the differences between effective doses measured using single and double dosimeters. Interventional radiology workers wore dosimeters at three positions: the neck outside the lead collar, the left chest outside the lead apron, and inside the lead apron. Effective doses were estimated using the single and double dosimeter methods specified in GBZ 128-2019 Specifications for individual monitoring of occupational external exposure, and the impact of different wearing positions on the estimation results was compared. Geant4 Monte Carlo simulations were used to model dose distributions at the neck outside the lead collar and at the left chest outside the lead apron for operators performing cardiovascular interventions under tube voltages of 70, 80, 90, and 100 kVp and exposure angles of posteroanterior (PA), anteroposterior (AP), and left anterior oblique 45° (LAO45°) positions. The study assessed the impact of dosimeter wearing position on effective dose estimation. Results: Monte Carlo simulations demonstrated that neck doses consistently exceeded left chest doses across different tube voltages and exposure angles, with neck-to-chest dose ratios of 0.80-0.90. Under identical tube voltage conditions, AP showed the highest doses, followed by LAO45°, and PA demonstrated the lowest doses. The single and double dosimeter methods exhibited consistent patterns in effective dose estimation. Single dosimeter method generally yielded higher effective doses with relative deviations of 9.9% to 83%, though these deviations decreased under high tube voltages. Field monitoring data indicated that most interventional radiology workers maintained relative deviations between single and double dosimeter calculations below 6%, with neck-to-chest dose ratios of 0.95-1.1. The estimation patterns remained consistent across both methods, though single dosimeter method showed slightly higher results. Conclusion: Under PA, AP, or LAO45°, the doses at the neck consistently exceeded those at the left chest. Therefore, when wearing lead protective equipment, the dosimeter should be properly positioned at the neck outside the lead collar to accurately reflect the radiation doses of surgeons. Some interventional radiology workers improperly positioned the dosimeter (intended at the neck outside the lead collar) at the left chest outside the lead apron, and this may result in an underestimation of the effective dose.
Objective: To explore the application value of anhydrous ethanol as an alternative to methanol in the preparation of chromosomal specimens from peripheral blood lymphocytes, and to establish a set of quantitative analytical methods for objectively evaluating the effectiveness of specimen preparation. Methods: Residual blood samples from routine laboratory slide preparation were used for lymphocyte culture. The standard slide preparation method was employed. The fixative in the control group was methanol and glacial acetic acid (3∶1). Four experimental groups were set up based on the ratio of anhydrous ethanol to glacial acetic acid in the fixative (volume ratios of 3∶1, 5∶1, 7∶1, and 9∶1 for experimental groups 1, 2, 3, and 4, respectively). A chromosomal analysis was conducted using an automated chromosome scanning/image analysis system to evaluate the morphology and dispersion of metaphase chromosomes in both control and experimental groups. Comparisons were made between the control and experimental groups regarding the dic + r aberration rate, ace aberration rate, chromosomal aberration rate, chromosome dispersion index, chromosome overlapping ratio, and dispersion index/overlapping ratio. Results: Microscopic evaluation revealed that the preparation quality of experimental groups 1 and 2 was comparable to the control group. No statistically significant differences were observed in dic + r aberration rate between each of the experimental groups and the control (P > 0.05). All experimental groups except group 4 showed no significant differences in ace aberration rate and chromosome aberration rate compared with the control group (P > 0.05). Experimental groups 1 and 2 showed no significant differences in chromosome dispersion index, overlapping ratio, and dispersion index/overlapping ratio compared with the control group (P > 0.05). Conclusion: A mixture of anhydrous ethanol and glacial acetic acid at a 5∶1 ratio is recommended for use as a fixative in the preparation of chromosomal specimens from peripheral blood lymphocytes. A quantitative index system for assessing the quality of chromosomal specimens was established, enabling objective evaluation of slide preparation effectiveness.
Objective: Radiation-induced brain injury (RIBI) is a common complication of radiotherapy for the head and neck tumors, and the current treatment methods are limited. Repetitive transcranial magnetic stimulation (rTMS), as a non-invasive neural regulation technique, has shown great potential in neuroprotection. However, the parameter selection and biological safety of rTMS in the prevention and treatment of RIBI have not been reported. Methods: Using a mouse model of RIBI, this study employed three rTMS frequencies (5, 10, and 25 Hz) for intervention. Biochemical and pathological assays were conducted to identify the optimal stimulation parameter. Subsequently, this parameter was used to evaluate the biological safety in normal mice. Results: Under the conditions of this experiment, rTMS interventions with all three frequencies could reduce the levels of serum brain injury markers (NSE and S100B) and inflammatory factors in mice (P < 0.001), and alleviate the morphological and structural damage of hippocampal tissue. The 10 Hz rTMS could significantly promote hippocampal neurogenesis in RIBI mice (P < 0.05). Furthermore, 10 Hz rTMS showed no significant effects on the cognitive function and mood of normal mice. The intervention did not significantly change the morphology and structure of the main organs, blood biochemical indicators, and the level of hippocampal neurogenesis in mice. Conclusion: The 10 Hz rTMS is optimal for the prevention and treatment of RIBI with high biological safety.
Objective: To explore the value of CT signs and quantitative parameters of artificial intelligence (AI) in predicting the efficacy of neoadjuvant chemotherapy for colorectal cancer. Methods: A total of 349 colorectal cancer patients who received neoadjuvant chemotherapy at Cangzhou Hospital of Integrated Traditional Chinese and Western Medicine in Hebei Province from January 2022 to January 2025 were selected and and divided into the effective group (n = 267) and the ineffective group (n = 82) according to the evaluation criteria for the efficacy of solid tumors. Conduct a CT examination and extract AI quantitative parameters from the CT images based on the lesion. The data were analyzed using SPSS21.0 software, Logistic regression was used to screen the influencing factors of ineffective neoadjuvant chemotherapy in patients with colorectal cancer, and separate and combined models of CT signs and AI quantitative parameters were established. The predictive effect of the model was verified by using the ROC curve, calibration curve and decision curve. Results: Compared with the effective group, the proportion of regular tumor morphology and the proportion of non-enlarged lymph nodesin the ineffective group were smaller. The tumor volume, peak value and entropy value were larger (P < 0.05). Multivariable analysis showed that irregular shape (OR= 4.216), presence of lymph node enlargement (OR = 8.998), larger tumor volume (OR = 1.109), higher average CT value (OR = 1.120), elevated peak value (OR = 2.528), and increased entropy value (OR = 1.390) were independent risk factors for ineffective neoadjuvant chemotherapy in colorectal cancer (P < 0.05). The areas under the ROC curves of the individual and combined models of CT signs and AI quantitative parameters were 0.777, 0.818, and 0.877, respectively(P < 0.05). The calibration curve showed a Brier score of 0.091. The decision curve showed that the threshold was between 0.10 and 0.85, and the combined model achieved a relatively high net clinical benefit. Conclusion: CT signs combined with AI quantitative parameters has a predictive value for the efficacy of neoadjuvant chemotherapy in colorectal cancer. To provide evidence-based basis for clinical screening of the population benefiting from chemotherapy and optimization of treatment strategies.
Objective: To analyze the scanning parameters and radiation dose characteristics of pediatric CT examinations in Jiangxi Province, China, and to provide a basis for optimizing radiation protection in children. Methods: The data of
Objective: To explore the clinical effectiveness of a locally trained and re-optimized RapidPlan model in lung stereotactic body radiation therapy (SBRT). Methods: A total of 132 lung SBRT cases were retrospectively collected as a training group for the establishment of an initial RapidPlan model (RP-1) in the Eclipse 15.5 treatment planning system. RP-1 was then used to optimize the training group plans to generate the first-generation RapidPlans, which were used as a new training group to generate the upgraded RapidPlan model (RP-Plus). Additional 40 lung SBRT cases were selected to verify the quality and efficiency of RP-Plus plans, which were further assessed through clinical quality assurance (QA). Results: The RP-Plus reduced the average number of optimization cycles by 2.1 times and 0.3 times compared to manual and RP-1 methods, respectively, and reduced the optimization time by 57.6% and 18.8%. The conformity index met clinical requirements, and the gradient index and Max2cm(%) were improved compared to RP-1 (both P < 0.05). The RP-Plus plans showed lower dosimetric parameters of organs at risk, including lung V20Gy, spinal cord Dmax, and heart
Objective: To investigate the levels of radionuclides in food in Beijing, China, and assess the committed effective dose to local residents from food intake. Methods: From 2021 to 2022, a total of 65 food samples across 7 categories were collected in Beijing. The activity concentrations of radionuclides, including 137Cs, 210Pb, 238U, 228Ra, 226Ra, 40K, 90Sr, 210Po, 3H and 14C, were measured using gamma spectrometry and radiochemical methods. By combining the monitoring results with dietary consumption data of Beijing residents and the internal dose coefficients for Chinese reference adult phantom, the committed effective dose was estimated. Results: The levels of radionuclides in food in Beijing were within the normal background range, consistent with related surveys in China and abroad, with activity concentrations below national standard limits. No significant differences were found in the activity concentrations of 137Cs, 238U, 228Ra, 226Ra and 40K between food samples collected from key areas and those from control areas (P > 0.05). The committed effective doses calculated according to internal dose coefficients for Chinese reference adult male phantom and GB 18871-2002 were 0.26 mSv and 0.19 mSv, respectively. Based on the Chinese reference adult male phantom, the majority of the committed effective dose was attributed to 210Pb (45.1%), 228Ra (37.1%), 210Po (12.3%), and 226Ra (4.7%). Conclusion: The levels of radionuclides in food in Beijing fluctuated within the background range, resulting in a low radiation dose burden to the population.
Objective: To measure radiation filed distribution in the treatment room of the Varian Halcyon medical linear accelerator, and to provide a basis for shielding design and potential exposure analysis of treatment rooms for this type of accelerator. Methods: Under the 6 MV X-ray (FFF) mode at a maximum dose rate of 800 MU/min and a maximum irradiation field of 28.00 cm × 28.00 cm, a total of 540 MU was delivered during gantry rotation. Radiation field distribution was measured using thermoluminescence dosimeters located at multiple points in the room. The measured data were then applied to shielding calculations, and the results were compared with those obtained using empirical formulas. Results: The overall radiation levels in the treatment room were in the range of 12.2 µGy/540 MU to 5.520 Gy/540 MU, with the highest dose (5.520 Gy/540 MU) observed at the isocenter, and the lowest dose (12.2 µGy/540 MU) recorded at approximately 6.5 m from the gantry head. The radiation levels at most points were within the range of 100-
Objective: Based on the “excellent” performance achieved by our institution in the 2024 national intercomparison of monitoring individual dose from external exposure, this paper systematically summarizes key technical elements and optimization experiences in instrument calibration, operational protocols, and data analysis, aiming to provide methodological references and practical support for continuously enhancing the accuracy and reliability of individual dose monitoring. Methods: As a participant in the intercomparison activity, our laboratory strictly followed the technical protocol formulated by the Chinese Center for Disease Control and Prevention. Results: In the 2024 national intercomparison of monitoring individual dose from external exposure, the measurement results met the criteria of single-group performance
Objective: To investigate the entrance surface dose (ESD) of dental radiological diagnosis and treatment devices in Nanping City of Fujian Province, China, assess the radiation risk differences between cone beam computed tomography (CBCT) and conventional oral panoramic tomography (COPT), and compare the output dose levels between domestic and imported devices and between public and private medical institutions, and to provide evidence for optimizing radiation protection strategies. Methods: A cross-sectional survey was conducted on 38 extraoral dental X-ray devices from 38 dental institutions in Nanping City. Measurements of ESD for different exposure types (adult/child COPT and CBCT) were performed using an adult head-and-neck phantom and thermoluminescent dosimeters. A statistical analysis (Mann-Whitney U test) was applied to compare dose differences by device type and institution type. Results: The median tooth-region doses for adult/child CBCT (8.97/6.80 mGy) were significantly higher than those of adult/child COPT (0.33/0.24 mGy), with the 75th percentile values (12.44/8.18 mGy) exceeding the national guideline level of 7 mGy. Domestically manufactured devices demonstrated higher median doses and greater dose variability compared to imported devices (P < 0.05). Private institutions exhibited inferior dose control stability relative to public institutions (P < 0.001). CBCT delivered substantially higher radiation exposure to the thyroid and ocular lenses, with child lens dose reaching 5.9 times that of COPT. Conclusion: Dental CBCT radiation doses in Nanping City exceed the guideline level. Enhanced protection for sensitive organs, restriction of unnecessary pediatric examinations, technological upgrades for domestic devices, and strengthened regulation and operational standardization of private institutions are critical to achieve precise radiation protection and improved medical quality.
Objective: To establish radioresistant human non-small cell lung cancer NCI-H460R model cells and evaluate the sensitivity of these radioresistant cells to a ferroptosis inducer. Methods: Radioresistant cell lines, designated as NCI-H460 R20Gy and NCI-H460 R116Gy, were generated by subjecting parental NCI-H460 cells to fractionated irradiation with varying cumulative doses. Both parental cells and the established radioresistant cell lines were each randomly divided into four groups and exposed to irradiation at 0, 2, 4, and 6 Gy, respectively. Successful establishment of the radioresistant cell lines was confirmed by colony formation assay. Subsequently, cells were treated with increasing concentrations of the ferroptosis inducer RSL-3 to assess differential sensitivity between parental and radioresistant cells to ferroptosis. Results: In comparison to the parental NCI-H460 cells (D0WT=1.2), both NCI-H460 R116Gy and NCI-H460 R20Gy cells exhibited radioresistance, with NCI-H460 R116Gy demonstrating a stronger radioresistance (D0R116Gy=1.5) than NCI-H460 R20Gy (D0R20Gy=1.4). Furthermore, NCI-H460 R116Gy cells exhibited increased sensitivity to RSL-3 relative to the parental cells (P < 0.001), while NCI-H460 R20Gy cells did not display a significant difference in sensitivity to RSL-3. Conclusion: Human non-small cell lung cancer cells with radioresistance induced by a high cumulative irradiation dose exhibit increased sensitivity to the glutathione peroxidase 4-specific ferroptosis inducer RSL-3. This finding provides an experimental basis for optimizing combined treatment regimens involving radiotherapy and RSL-3 for non-small cell lung cancer patients with radiotherapy resistance.
Objective: To evaluate the accuracy of multiparametric imaging on the dual-source CT through acceptance and commissioning testing, and to provide a reference for standardized clinical application. Methods: Both the adult and pediatric dual-source CT scanning modes were used to scan the electron density phantom, and identical multiparametric image reconstruction tasks were performed, including the conventional CT images, the mixed CT images, the virtual monoenergetic images, the iodine images, the electron density images, and the effective atomic number images. Results: In the adult scanning mode, the virtual monoenergetic CT numbers showed the greatest difference for the cortical bone (
Objective: To investigate the expansion margins of the planning target volume (PTV) and the planning organ at risk volume (PRV) in nasopharyngeal carcinoma patients immobilized with Styrofoam and head-neck-shoulder mask. Methods: A convenient sample of 33 nasopharyngeal carcinoma patients who received radiotherapy at Huanggang Central Hospital from January to October 2024 were selected as the research subjects. All patients underwent cone beam CT scans during the first three treatments and weekly thereafter. After registration and calibration, the setup errors in the X (LAT), Y (LNG), and Z (VRT) directions were recorded. Statistical analysis was performed on the setup errors in each direction to determine differences, and the expansion margins for PTV and PRV were calculated using empirical formulas. Results: A total of 229 cone beam CT images were collected. Statistical analysis found that the setup errors (systematic error ± random error) of the patients in the X, Y, and Z directions were 1.05 ± 0.72, 1.30 ± 0.80, and 1.29 ± 0.82 mm, respectively. The expansion margins for PTV in the left-right, superior-inferior, and anterior-posterior directions were 1.40, 1.76, and 1.8 mm, respectively. The expansion margins for PRV in these directions were 0.83, 1.02, and 1.05 mm, respectively. Conclusion: For patients immobilized using Styrofoam and head-neck-shoulder mask, it is recommended that the expansion margins for PTV and PRV be set at 2 mm and 1 mm, respectively, in the left-right, superior-inferior, and anterior-posterior directions, and the PRV margin for the spinal cord be set at 3 mm in all directions.
Radiation-induced skin injury is one of the common adverse reactions of radiotherapy, involving skin, blood vessels, glands, and bones, and may even lead to carcinogenesis. It is characterized by high incidence, long treatment process, and high cost. In recent years, adipose-derived mesenchymal stem cells and their secreted exosomes have become a research hotspot in tissue repair. Exosomes can secrete a variety of cytokines related to wound repair and exhibit various biological functions, including inhibition of oxidative stress, modulation of inflammation, regulation of DNA damage repair, promotion of cell proliferation and migration, reduction of fibrosis, and regulation of the extracellular matrix. Exosomes are currently a major source of cytokines in the field of tissue repair and regeneration. This article reviews the application and therapeutic prospects of adipose-derived mesenchymal stem cell exosomes in radiation-induced skin injury, aiming to provide new ideas for the clinical treatment of this condition.
