Objective To investigate the current distribution of radiotherapy resources in Gansu Province, evaluate the equity of resource allocation, and provide a scientific basis for optimizing regional resource allocation. Methods A questionnaire survey was carried out to assess radiotherapy resources in medical institutions across Gansu Province, China. The equity of radiotherapy resource distribution and associated disparities were assessed using the Gini coefficient, Lorenz curve, and Theil index. Results A total of 23 medical institutions in Gansu Province provided radiotherapy services, comprising 39 radiotherapy devices and 438 professionals, of whom medical physicists accounted for 16.9%. The radiotherapy frequency was 0.47 cases per thousand population. The Gini coefficients for radiotherapy resource distribution ranged from 0.38 to 0.56 by population and from 0.52 to 0.70 by geography. The Theil index for radiotherapy resources ranged from 1.36 to 3.67. Conclusion Radiotherapy resources in Gansu Province were insufficient, and the capacity of radiotherapy service was suboptimal. The equity of radiotherapy resource allocation by geography was worse than that by population. Therefore, it is imperative to address the shortage of radiotherapy resources, strengthen the professional workforce, enhance the capacity radiotherapy service and resource utilization, optimize resource allocation, and promote regional equity in radiotherapy provision in Gansu Province.

Objective To explore the clinical factors influencing complete response in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (nCRT). Methods Clinical data of LARC patients treated in the Department of Radiation Oncology at Beijing Shijitan Hospital between January 2013 and December 2024 were retrospectively collected. All patients received nCRT, after which surgery or a watch-and-wait approach was adopted based on treatment response. Univariable and multivariable logistic regression analyses were performed to identify prognostic factors influencing complete response. A clinical prediction model was constructed based on the multivariable analysis results, and its predictive performance was evaluated using the receiver operating characteristic curve. Results A total of 113 eligible patients were included. After nCRT, 19 patients (16.8%) achieved complete response, including 3 with clinical complete response and 16 with pathological complete response. Univariable analysis indicated that pretreatment clinical N stage, extramural venous invasion, carcinoembryonic antigen level, and neoadjuvant treatment regimen were associated with complete response after nCRT (P<0.05). Multivariable logistic regression analysis identified pretreatment extramural venous invasion, carcinoembryonic antigen level, and neoadjuvant treatment regimen as independent influencing factors for complete response (P<0.05). A prediction model incorporating these independent factors yielded an area under the receiver operating characteristic curve of 0.813 (95% confidence interval: 0.713-0.913), with a sensitivity of 89.5% and a specificity of 60.6%, demonstrating good predictive performance. Conclusion Pretreatment extramural venous invasion, carcinoembryonic antigen level, and neoadjuvant treatment regimen are independent factors influencing complete response after nCRT in LARC patients. The prediction model combining these factors may assist in evaluating treatment efficacy following nCRT in LARC patients.

Objective To analyze the unexamined items and situations in occupational health examinations of radiation workers, and provide a reference for the revision of occupational health examination standards for radiation workers. Methods A total of 29 630 radiation workers who underwent occupational health examinations at The Third People’s Hospital of Henan Province in 2023 were selected, and the non-examination rates were statistically analyzed according to occupation, gender, and age. Results The overall non-examination rate of non-medical radiation workers was significantly lower than that of the medical radiation workers (P<0.05). The non-examination rate of chest X-rays among medical radiation workers was significantly higher than that of non-medical radiation workers (P<0.05), while no significant differences were found in other items (P>0.05). Gender-stratified analysis showed that the non-examination rate of routine urine tests was higher in females than in males in both medical and non-medical radiation workers (P<0.05). Age-stratified analysis revealed no significant differences in non-examination rates among different age groups in non-medical radiation workers (P>0.05), whereas the chest X-ray non-examination rate was relatively high in medical radiation workers under 30 years old (P<0.05). Conclusion Significant differences were observed in the non-examination rates of occupational health examinations among radiation workers based on occupation, gender, and age. The overall non-examination rate was relatively low in non-medical radiation workers.

Objective To investigate the causes of the abnormally elevated gross α and gross β activity concentrations in the water of Nanbei Lake located near the Qinshan Nuclear Power Plant. Methods Water and sediment samples were measured according to GB/T 5750.13-2023 Standard Examination Methods for Drinking Water. Results The gross α activity concentration in Nanbei Lake water was (0.135 ± 0.0108) Bq/L, and the gross β activity concentration was 0.345 ± 0.036 Bq/L, which were several times higher than those recorded during the same period in previous years. The spike recovery rates for Nanbei Lake water (gross α: 85.7% ± 4.7%; gross β: 101.8% ± 4.1%) showed no significant differences from those for tap water (gross α: 83.2% ± 3.6%; gross β: 105.1% ± 5.2%). Gross α activity concentration exhibited a positive correlation with sediment addition (r = 0.996), as did gross β activity concentration (r = 0.998). The gross α and gross β activity concentrations in sediments from Nanbei Lake were significantly higher than those in sediments from surrounding water bodies. The gross α (529 ± 41)Bq/L and gross β (927 ± 83)Bq/L activity concentrations in the residue retained on a 0.45 μm filter after filtering Nanbei Lake water were similar to those in the sediments of Nanbei Lake (gross α: (516 ± 35) Bq/L; gross β: (965 ± 68) Bq/L). Conclusion The elevated gross α and gross β activity concentrations in Nanbei Lake water could be attributed to dredging activities, which resuspended sediments into the water column, combined with the inherently high activity concentrations in the sediments.

Objective To evaluate the radiation dose levels induced by secondary neutrons at different locations inside proton therapy treatment rooms, and analyze the distribution characteristics of neutron energy spectra by combining experimental measurements with simulations, and to provide a theoretical basis and technical support for radiation protection design and management in proton therapy. Methods Multiple representative measurement points were established in the treatment rooms of two hospital-based proton therapy centers. The DIAMON neutron spectrometer was employed to perform in-situ measurements of secondary neutron doses and energy spectra. Three-dimensional simulation models of treatment rooms were constructed using the FLUKA code to simulate the generation and transport of secondary neutrons. Results Measurements showed that the neutron dose was highest near the target region, reaching up to 4293.750 µSv/h. The doses at the maze entrance were the next highest, ranging from 422.091 to 489.268 µSv/h, while the doses in the middle section of the maze ranged from 2.860 to 6.727 µSv/h. The neutron energy spectra exhibited a triple-peak pattern. Conclusion Significant accumulation of secondary neutrons was observed near the target and in the maze regions during proton therapy, with intermediate-energy neutrons being the dominant dose contributor. The consistency between measurements and simulations validated the reliability of the model, which can provide a basis for optimizing treatment room shielding and controlling occupational exposure for staff.

Objective To develop an automated system for the determination of gross α and gross β activity concentrations in water, and to support the rapid and automated monitoring of environmental water bodies. Methods Based on the thick source method, microwave evaporation-ashing was used to replace conventional electric hotplate heating. A grinder and a sample-spreading device were designed and operated via a robotic arm, achieving fully automated pretreatment, sample preparation, and measurement. Results Spike recovery tests demonstrated that the recovery rates were 95.7%-102.5% for gross α and 97.2%-108.1% for gross β. The relative standard deviations were 4.1%-7.8% for gross α and 5.9%-7.7% for gross β. Compared with manual laboratory methods, the average relative errors were 2.17%-6.25% for gross α and 4.17%-6.90% for gross β. The sample preparation time was reduced from an average of 72 hours to less than 5 hours, representing an efficiency improvement of over 90%. Conclusion The developed system enables rapid, accurate, and fully automated monitoring of gross α/β radioactivity, making it suitable for online monitoring of environmental water bodies. It can provide timely data on the radiological indicators of water bodies for environmental protection and water resource management authorities.

Objective To retrospectively analyze the impact of low-dose computed tomography (LDCT) parameter optimization on the diagnostic accuracy for pulmonary nodules and their radiation exposure, and to provide a basis for balancing diagnostic performance and radiation safety. Methods Data from 300 high-risk individuals who underwent pulmonary LDCT screening at Wuhan Hospital of Traditional Chinese Medicine between January 2023 and December 2024 were collected. Participants were divided into an optimized LDCT group (n = 150; 100 kV, 70-90 mA) and a traditional LDCT group (n = 150; 120 kV, 140-160 mA) based on scanning parameters. Baseline characteristics, radiation dose, image quality, and diagnostic accuracy were compared between the two groups. Key factors influencing diagnostic accuracy were analyzed. Results In the optimized group, the volume CT dose index, dose-length product, and effective dose decreased by over 40% (t = 37.492, 35.351, and 35.262, respectively, all P<0.001). Similarly, tube voltage and current decreased significantly (t = 14.582 and 28.653, respectively, both P<0.001), while scan time showed no significant change (t = 0.321, P = 0.760). The overall image quality score of the optimized group was slightly lower than that of the traditional group (4.21 ± 0.43 vs. 4.38 ± 0.39; t = 3.587, P<0.001), but remained within the good-to-excellent range. Both groups demonstrated high diagnostic confidence (4.25 vs. 4.41; t = 3.361, P = 0.001) and high inter-evaluator consistency as indicated by an intraclass correlation coefficient of 0.82. No significant differences were observed between the two groups in sensitivity (94.83% vs. 96.43%; Z = 0.393), specificity (91.30% vs. 90.22%; Z = 0.292), accuracy (92.78% vs. 93.33%; χ² = 0.031), and area under the receiver operating characteristic curve (0.931 vs. 0.938; Z = 0.202) (all P>0.05). Diagnostic performance for<6 mm nodules showed no significant difference (P = 0.778). Multivariable analysis identified nodule size, solid density, lobulated margins, and image quality score as independent predictors of diagnostic accuracy. Conclusion Optimized LDCT can significantly reduce radiation exposure (by over 40%) while maintaining diagnostic accuracy for pulmonary nodules, including small nodules, and good image quality, making it suitable for lung cancer screening in high-risk populations.

Objective To address the safety challenges arising from the rapid development of nuclear energy and technology, assess the current status of health emergency response capabilities in nuclear radiation emergencies, and promote capacity enhancement. Methods A preliminary evaluation system for health emergency response capability in nuclear radiation emergencies was developed based on a literature review. Two rounds of Delphi expert consultation (n = 20) were conducted, and the analytic hierarchy process was employed to establish judgment matrices for assigning indicator weights. Results The finalized system included six primary indicators (radiation protection capability, triage capability, decontamination and evacuation capability, medical treatment capability, radiation detection capability, and radiation dose estimation capability), along with 29 secondary indicators, such as capability for setting up emergency zones, capability for protecting personnel from internal and external contamination, on-site first aid capability, and personal dose monitoring capability. The expert response rate was 0.95, and the expert authority coefficient reached 0.80. The Kendall’s coefficient of concordance was W = 0.288 (P<0.01) for the first round of expert consultation and W = 0.308 (P<0.01) for the second round. Both rounds demonstrated high agreement among experts, and the consultation questionnaires passed reliability and validity tests. Conclusion By integrating qualitative analysis and quantitative calculation, this study developed a scientifically sound and operationally feasible evaluation system. This system will help identify gaps in health emergency response capabilities and provide scientific guidance and a decision-making basis for optimizing emergency plans and improving the level of health emergency response in nuclear radiation emergencies.

Objective To explore the change pattern of quantitative parameters in contrast-enhanced computed tomography (CECT) scans during the cortical and nephrographic phases in patients with clear cell renal cell carcinoma (ccRCC), evaluate the diagnostic efficiency of these quantitative parameters in predicting the pathological grade of ccRCC preoperatively, and provide imaging reference for clinically evaluating preoperative disease severity and formulating individualized therapeutic regimens. Methods A retrospective analysis was performed on the clinical data of 84 patients with ccRCC treated in our hospital between September 2022 and September 2024. According to the World Health Organization/International Society of Urological Pathology (WHO/ISUP) pathological grading system, patients were divided into a high-grade group (n = 32) and a low-grade group (n = 52). CECT features and quantitative parameters were compared between the two groups. The relationships between CECT quantitative parameters and pathological grading in ccRCC patients were analyzed using Spearman correlation. The diagnostic value of these parameters for preoperative pathological grading was evaluated using receiver operating characteristic curves. Results The maximum tumor diameter and the proportion of tumors with blurred margins were higher in the high-grade group than in the low-grade group (P<0.05). The CT values, net enhancement values, and enhancement rates during both the cortical and nephrographic phases were lower in the high-grade group than in the low-grade group (P<0.05). Spearman correlation analysis showed that the CT values, net enhancement values, and enhancement rates during both the cortical and nephrographic phases were negatively correlated with preoperative pathological grades in ccRCC patients (P<0.05). Receiver operating characteristic curve analysis revealed that the area under the curve for preoperative pathological grading using the combination of cortical phase CT value, cortical phase net enhancement value, cortical phase enhancement rate, nephrographic phase CT value, nephrographic phase net enhancement value, and nephrographic phase enhancement rate was 0.912, which was higher than the areas for any individual parameter used alone (0.770, 0.748, 0.763, 0.751, 0.739, and 0.718, respectively; P<0.05). The sensitivity, specificity, and 95% confidence interval for the parameters used in combination were 96.88%, 69.23%, and 0.853-0.970, respectively. Conclusion CECT quantitative parameters were negatively correlated with pathological grades in patients with single ccRCC and demonstrated high diagnostic efficiency for pathological grading, providing a reference for clinical treatment planning.

Objective To introduce the causes of accidents and the diagnosis and treatment of two patients with radiation-induced skin injury admitted to our hospital in 2023, and to provide a reference for the clinical treatment of subsequent radiation-induced skin injury. Methods The clinical treatment process of two patients with acute skin injury caused by external radiation exposure were summarized and analyzed. Results The exposure history of the two patients was reconstructed, the flaw detection scenario was simulated, the biological dose and hand skin exposure dose were estimated, and the infrared thermal imaging device was used for dynamic monitoring. A comprehensive analysis was conducted based on clinical manifestations and other data. The diagnosis of “Xie” was excessive exposure combined with acute radiation-induced skin injury on both hands (Grade IV for the right hand palm, index finger, and middle finger and Grade II for the left hand little finger). The diagnosis of “Hao” was acute radiation-induced skin injury on both hands (Grade I). The two patients received different clinical treatment measures: “Xie” was treated with both local and systemic therapies, while “Hao” was mainly treated with systemic therapy. Conclusion After systematic and effective treatment, the radiation-induced skin injuries healed in both patients.