Objective:To optimize the image quality of PET/CT following 90Y-selective internal radiation therapy ( 90Y-SIRT) using block-sequential regularized expectation maximization (BSREM) reconstruction algorithm, and to evaluate its impact of different β values on image quality and quantitative analysis. Methods:A retrospective study was conducted on 8 male patients with hepatic tumors (age: 62(52, 71) years) treated at Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine Tsinghua University, between June 2024 and January 2025. All patients were treated with 90Y resin microspheres (2.6(0.9, 3.6)GBq) and underwent post-treatment 90Y PET/CT liver imaging. Imaging data were reconstructed using BSREM with different noise penalty weighting factors ( β values: 0, 300, 1000, 1500, 2500, 3500, 4000, 6000, 8000, 10000). Visual assessment was independently performed by two nuclear medicine physicians, using a 4-point scale (1=worst, 4=best). The mean score was considered as the final score. The consistency of the 2 reviewers was calculated and analyzed by Kappa test. Visual scores of different β value groups were compared by Friedman test. The β value demonstrating highest mean score and optimal consistency was selected as the optimal. Quantitative analysis was performed using MIM software to calculate the maximum absorbed dose ( Dmax) and the mean absorbed dose ( Dmean) for tumor, normal liver, and whole liver regions, and the CV was used to evaluate the impact of β values. Results:The visual assessment consistency of reviewers in 3 β value groups (0, 3500, 6000) were the highest (7/8) (all kappa=0.88, all P<0.05). Visual scores of the 10 β value groups were significantly different ( χ2=28.74, P<0.001), and the visual scores of 2 β value groups (3500, 4000) were the highest, both of which were 4.0(4.0, 4.0). Overall, visual assessment identified β=3500 as the optimal. Quantitative analysis revealed that, (1) Dmax in all regions (tumor, normal liver, whole liver) decreased with the increasing β values, stabilizing when β>1000 ( CV 56%-67%); (2) Dmean remained stable across different β values ( CV 0.04%-5.00%). Conclusions:In BSREM reconstruction, β=3500 is the optimal parameter for improving 90Y-PET image quality. β values significantly affect Dmax (stabilizing at β > 1000), but have no significant impact on Dmean, suggesting that reconstruction parameters primarily influence dose distribution morphology rather than average dose assessments.

This case report describes a 68-year-old male patient diagnosed with primary hepatocellular carcinoma (HCC). After receiving Yttrium-90 microsphere selective internal radiation therapy (⁹⁰Y-SIRT), the tumor significantly reduced in size, and tumor markers alpha fetoprotein (AFP) and abnormal prothrombin (PIVKA-Ⅱ) decreased. Postoperative pathological results showed minimal residual tumor cells, indicating that ⁹⁰Y-SIRT has good efficacy and safety in downstaging and conversion of HCC, thereby facilitating subsequent surgical resection.

Objective:To optimize the image quality of PET/CT following 90Y-selective internal radiation therapy ( 90Y-SIRT) using block-sequential regularized expectation maximization (BSREM) reconstruction algorithm, and to evaluate its impact of different β values on image quality and quantitative analysis. Methods:A retrospective study was conducted on 8 male patients with hepatic tumors (age: 62(52, 71) years) treated at Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine Tsinghua University, between June 2024 and January 2025. All patients were treated with 90Y resin microspheres (2.6(0.9, 3.6)GBq) and underwent post-treatment 90Y PET/CT liver imaging. Imaging data were reconstructed using BSREM with different noise penalty weighting factors ( β values: 0, 300, 1000, 1500, 2500, 3500, 4000, 6000, 8000, 10000). Visual assessment was independently performed by two nuclear medicine physicians, using a 4-point scale (1=worst, 4=best). The mean score was considered as the final score. The consistency of the 2 reviewers was calculated and analyzed by Kappa test. Visual scores of different β value groups were compared by Friedman test. The β value demonstrating highest mean score and optimal consistency was selected as the optimal. Quantitative analysis was performed using MIM software to calculate the maximum absorbed dose ( Dmax) and the mean absorbed dose ( Dmean) for tumor, normal liver, and whole liver regions, and the CV was used to evaluate the impact of β values. Results:The visual assessment consistency of reviewers in 3 β value groups (0, 3500, 6000) were the highest (7/8) (all kappa=0.88, all P<0.05). Visual scores of the 10 β value groups were significantly different ( χ2=28.74, P<0.001), and the visual scores of 2 β value groups (3500, 4000) were the highest, both of which were 4.0(4.0, 4.0). Overall, visual assessment identified β=3500 as the optimal. Quantitative analysis revealed that, (1) Dmax in all regions (tumor, normal liver, whole liver) decreased with the increasing β values, stabilizing when β>1000 ( CV 56%-67%); (2) Dmean remained stable across different β values ( CV 0.04%-5.00%). Conclusions:In BSREM reconstruction, β=3500 is the optimal parameter for improving 90Y-PET image quality. β values significantly affect Dmax (stabilizing at β > 1000), but have no significant impact on Dmean, suggesting that reconstruction parameters primarily influence dose distribution morphology rather than average dose assessments.

China attaches great importance to the occupational health assistance for small and medium-sized enterprises, but many efforts are still needed. Through the research and comparative analysis of the policies and measures of occupational health assistance for small and medium-sized enterprises at domestic and international, this paper finds that there are still some problems in the occupational health assistance for small and medium-sized enterprises in China, such as imperfect policies, lack of safeguard measures, support platforms and resources, and puts forward that China can promote the occupational health assistance for small and medium-sized enterprises from the aspects of perfecting the support system, strengthening safeguard measures, building relevant platforms and enriching resources.

The risk management in workplace is an important measure to effectively prevent and control the harm of hand-transmitted vibration. Based on the relevant developments at home and abroad, this paper expounds the risk of manual vibration operation in workplace by taking contact assessment and hazard assessment as an example. On this basis, the limit management and hierarchical management related to risk management are discussed, and the existing problems are analyzed.

The occupational health issues of shift workers has received increasing attention in the field of occupational health, and discussed in this article through literature review on the health risks and management of shift work both domestically and internationally. Based on this, a series of impacts of shift work on the physiological and psychological health of workers, as well as their family and social life, are revealed. Combined with relatively mature regulations and policies in foreign countries, it is proposed that China should fully learn from the relevant experience of health management in shift work abroad, Strengthen research and explore effective management intervention measures to provide ideas for accelerating the development of scientifically feasible regulations and policies related to occupational health in shift work in China.

As an important force in promoting the transformation and upgrading of the national economy, the occupational health of the Internet industry's employees has received widespread attention. This paper examines the current situation of occupational health risks and management in the Internet industry at home and abroad, and on this basis reveals the physical and mental health problems of Internet industry employees. Combining the existing regulations, policies and standard documents at home and abroad, countermeasures are proposed to improve the relevant laws and regulations and their guidelines, implement relevant job design requirements, build a healthy working environment, optimise the work management system and carry out workplace health promotion, in order to provide ideas to accelerate the improvement of occupational health issues in the Internet industry.

In order to facilitate technical personnel related to occupational health and safety production to search, obtain, and master information on the hazard classification and health effects of chemical hazards, this article surveyed 14 commonly used foreign databases and 9 commonly used domestic databases, analyzed the characteristics, main content, scope of application, and network resources of each database, and considered the development of database for occupational health hazard of chemical hazards.

China attaches great importance to the occupational health assistance for small and medium-sized enterprises, but many efforts are still needed. Through the research and comparative analysis of the policies and measures of occupational health assistance for small and medium-sized enterprises at domestic and international, this paper finds that there are still some problems in the occupational health assistance for small and medium-sized enterprises in China, such as imperfect policies, lack of safeguard measures, support platforms and resources, and puts forward that China can promote the occupational health assistance for small and medium-sized enterprises from the aspects of perfecting the support system, strengthening safeguard measures, building relevant platforms and enriching resources.

The risk management in workplace is an important measure to effectively prevent and control the harm of hand-transmitted vibration. Based on the relevant developments at home and abroad, this paper expounds the risk of manual vibration operation in workplace by taking contact assessment and hazard assessment as an example. On this basis, the limit management and hierarchical management related to risk management are discussed, and the existing problems are analyzed.