Health physics最新文献

{"title":"Evaluation of Gamma Index Analysis for Detecting Errors in Patient-specific Quality Assurance in Intensity Modulated Radiotherapy.","authors":"Taylan Tuğrul","doi":"10.1097/HP.0000000000001933","DOIUrl":"https://doi.org/10.1097/HP.0000000000001933","url":null,"abstract":"<p><strong>Abstract: </strong>Quality assurance practices performed before treatment are believed to identify various potential errors. In this study, 2-dimensional (2D) dosimetric results were analyzed by making some intentional mistakes in six different treatment plans. In this way, the detectability of errors was investigated. In all segments of all treatment plans, one of the multileaf collimators was kept fixed at different positions on the central axis. In addition to multileaf collimators error, gantry error was also examined in the study. The dose distribution results obtained by Treatment Planning System (TPS) were compared with those obtained by the 2D array device, both as local calculation and global calculation methods, using the gamma analysis method. When the results are examined in the case where the Multi-leaf collimators (MLC) is fixed at the 1 cm position, the gamma analysis pass rate of the other plans, except two plans in the MD criterion, are calculated above the 95% limit. When the dose distributions obtained as a result of irradiation with 0.5-degree erroneous gantry angle were analyzed, it was found that all plans were at an acceptable rate in the maximum dose criterion. In case of incorrect irradiation, dose reduction or overdose may occur in the irradiated target area, even if gamma analysis pass rates are sufficient. Quality control procedures performed before treatment may be less effective. It is suggested that it would be better to examine the gamma analysis criteria applied for error detection with different values and local calculation method, and that device-based quality controls should be performed frequently.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":"128 6","pages":"437-441"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear Waste Tank Emission Contributions to Particle Size Distribution.","authors":"Brianna H Matthews, Stephen Noble","doi":"10.1097/HP.0000000000001952","DOIUrl":"10.1097/HP.0000000000001952","url":null,"abstract":"<p><strong>Abstract: </strong>Pollutants from anthropogenic activities including industrial processes are ubiquitous to the environment. To understand the impact from industrial aerosol on climate and human health, industrial aerosol needs to be better characterized. In this study, particle number concentrations were used as a proxy for atmospheric pollutants, which include both particles and gases. Particle concentration and size distribution were measured using a scanning mobility particle sizer (SMPS) approximately 4. 5 km from primary industrial areas at the Savannah River Site in Aiken, SC. Industrial areas include numerous nuclear waste storage and processing tanks. The SMPS data were divided into two groups depending on the wind direction measured onsite to categorize transport from the industrial area or from elsewhere. Industrial contributions were found to have a higher concentration of particles with sizes less than 200 nm , 859 ± 564 cm -3 , in comparison to non-industrial attributed particles, 733 ± 495 cm -3 on average from March-July 2021. For sizes larger than 200 nm , industrial and non-industrial particles have a similar concentration, 89 ± 59 cm -3 and 99 ± 61 cm -3 , with non-industrial concentrations being slightly larger. To confirm that industrial particles could travel to the sampling location, air dispersion modeling was completed for specific case studies during the sampling period. The atmospheric dispersion modeling results confirmed that particles released at the industrial areas reached the sampling location when the wind direction was favorable for transport from the industrial areas. The greater concentration of smaller-sized particles in industrial emissions has implications for typical particulate measurements (PM2.5), heath impacts, and climatological influences.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":"497-506"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiation Hardness Assurance by Redundancy in Raspberry Pi Zero W Computation Metrics via Total Ionizing Dose 60Co Testing for Spacecraft Applications.","authors":"Samuel C Hanson, Robert B Hayes","doi":"10.1097/HP.0000000000001940","DOIUrl":"10.1097/HP.0000000000001940","url":null,"abstract":"<p><strong>Abstract: </strong>This work showed the outcome from conducting formal total ionizing dose (TID) testing with a traditional 60Co source on commercial Raspberry Pi computer boards. Two Raspberry Pi boards inside a Gammacell 220 irradiator with continuous biased operations, voltage monitoring, and live computational testing and data extraction were exposed to dose rates of 2.61 ± 0.09 mGy(Si) s-1. The results showed potential tolerance doses approaching 500 Gy(Si). Computational tests included memory, calculation capability, voltage rail output, and I/O. Memory degradation was not observed alongside voltage rail and Input/Output. Individual test result deviations for CPU performance slightly increased in likelihood throughout accumulation of dose. Particular observed weakness included the SD card with potential strengths being use of redundancy and novel spot-shielding opportunities.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":"128 6","pages":"457-466"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143997956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of Effective Half-life of Iodine-131 to Optimize Safety Release Instructions after Treatment for Patients with Differentiated Thyroid Cancer.","authors":"Timothy Greist, Aaron Smith","doi":"10.1097/HP.0000000000001997","DOIUrl":"https://doi.org/10.1097/HP.0000000000001997","url":null,"abstract":"<p><strong>Abstract: </strong>Iodine-131 (131I) is a common therapy for treatment of differentiated thyroid carcinoma (DTC); however, its radioactivity poses a radiation safety risk to public health. There is inter-facility variation in release instructions to minimize incident exposure to other individuals. Isolation measures are not without harm. Most studies on this topic rely upon cumulative dosimetry to measure exposure, but this does not provide the researcher with critical dose protraction information. Refining estimation of elimination kinetics with more frequent exposure readings would help optimize radiation safety recommendations. Measuring radiation exposure from patients with DTC post-thyroidectomy receiving 131I would better quantify its elimination kinetics to improve radiation safety recommendations. Patients with DTC post-thyroidectomy undergoing radioiodine remnant ablation with 131I were instructed to measure exposure at a distance of 1 m, three times a day for 14 d, using an ion chamber at home. These data were used to form an exponential decay model and estimate the time after which cumulative exposure is below a reasonably low threshold. The average effective half-life was 15.8 h when calculated using real-time exposure readings from 32 patients. Among patients administered less than 4.22 GBq, cumulative effective dose is ≤1 mSv after 24 h of isolation. Between 4.22 and 6.03 GBq, cumulative effective dose is ≤1mSv after 48 h of isolation. Cumulative gamma radiation exposure at 1 m remains low enough to consider re-evaluating isolation protocols that encourage long-term distancing past the first 24 h in post-thyroidectomy patients treated with 131I for remnant ablation.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144198882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers: A Descriptive Cross-sectional Study.","authors":"Amirreza Sadeghinasab, Jafar Fatahiasl, Mahmoud Mohammadi-Sadr, Masoud Heydari Kahkesh, Marziyeh Tahmasbi","doi":"10.1097/HP.0000000000001991","DOIUrl":"https://doi.org/10.1097/HP.0000000000001991","url":null,"abstract":"<p><strong>Abstract: </strong>Magnetic resonance imaging (MRI) has revolutionized disease diagnosis and treatment. However, the technology poses safety risks, such as exposure to magnetic fields, RF pulses, and cryogens, necessitating strict adherence to safety protocols to protect patients and healthcare workers. This cross-sectional descriptive study assessed compliance with MRI safety standards in Khuzestan province, Iran) imaging centers, focusing on electromagnetic fields and other key safety domains. A 61-item researcher-developed checklist, based on international safety guidelines, was used to evaluate safety protocols in 11 MRI centers across seven domains, including facility design, equipment labeling, static magnetic and gradient fields, RF waves, cryogens, patient and staff protection, and infection control. MRI staff responded with yes/no answers. Responses to three additional questions also were collected. Data analysis was conducted using SPSS 26. A p-value < 0.05 was considered statistically significant. Overall, facility design scores ranged from 54.5% to 100%, but static magnetic field safety ratings were significantly lower (25% to 100%). Although safety equipment availability reached 100% in some centers, gaps were noted in labeling ferromagnetic devices. Infection control adherence was high, but only seven centers featured seamless flooring in the magnet room. Cryogen safety showed partial compliance with some centers lacking exhaust fans. Employee and patient safety measures were inconsistent, with one center scoring as low as 18%. While MRI centers demonstrated strengths in infection control and facility design, critical deficiencies in static magnetic field safety and emergency protocols highlight the need for targeted training, regular audits, and updated policies. Addressing these gaps is essential to enhancing MRI safety practices and aligning with international standards.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144077750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparative Study of 137Cs Dose Factors for Constant and Depth-dependent Soil Densities.","authors":"Necati Çelik, Nilay Akçay, Uğur Çevik","doi":"10.1097/HP.0000000000001995","DOIUrl":"https://doi.org/10.1097/HP.0000000000001995","url":null,"abstract":"<p><strong>Abstract: </strong>Accurate assessment of external radiation dose rates from 137Cs is essential for evaluating radiological risk in environmental and occupational settings. This study refines dose conversion coefficient calculations by incorporating depth-dependent soil density and addressing limitations in conventional methods that assume constant soil density. We calculated dose conversion coefficients for 137Cs in soil, considering both exponential and Gaussian distributions of activity concentration. Using two models, one with constant density and another with variable density as a function of depth, we compared dose rates to quantify the effect of soil density variations. Results indicate that dose rates are consistently higher when depth-dependent density is applied. The effect is more pronounced when 137Cs activity is distributed over larger depths (i.e., greater relaxation lengths) or when broader Gaussian distributions are considered. This suggests that assuming constant soil density may lead to underestimations of dose rates, especially in heterogeneous or compacted soils. Our findings emphasize the importance of accounting for density variability in dose calculations to enhance radiological risk assessments for areas contaminated with 137Cs.Health Phys. 129(0):000-000; 2025.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143994181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into Testicular Radiation Exposure in the Orthopedic Surgeon.","authors":"Taylor K Zak, Stephan Zmugg, Daniel Bouton, Jennifer Rodgers, Vivek Kalia, Neil Stewart, Jordan Polk, Kaitlyn Brown, Yassine Kanaan, Anthony I Riccio","doi":"10.1097/HP.0000000000001993","DOIUrl":"https://doi.org/10.1097/HP.0000000000001993","url":null,"abstract":"<p><strong>Abstract: </strong>Testicular radiation exposure has been linked to diminished spermatogenesis, male infertility, and potentially testicular cancer. Despite this, the risk of testicular exposure from intraoperative fluoroscopy to the male orthopedic surgeon has yet to be studied. The purpose of this study is to determine factors associated with unnecessary testicular radiation exposure in male orthopedic surgeons. The study was designed to answer the following questions: (1) Do the designs of lead apron protection result in any differential testicular radiation exposure? (2) Does the position of the surgeon (standing, sitting, and knee position while sitting) alter the amount of testicular radiation exposure? (3) Does any combination of lead apron design and surgeon positioning increase the degree of testicular radiation exposure? A life-sized, whole-body, anthropomorphic phantom simulating an orthopedic surgeon was positioned adjacent to a hand table attached to a standard radiolucent operating table. A digital dosimeter was attached to the groin region beneath a lead apron. Scatter radiation dose equivalent rates were measured during continuous anteroposterior C-arm fluoroscopy of a forearm/hand phantom. Four trials were conducted using three different types of protective lead aprons (cross-back, full-skirt, and half-skirt) in three different positions (standing, sitting with knees 10 cm apart, and sitting with knees 25 cm apart). Radiation dose-equivalent rates were compared using the Student's t-test and analysis of variance. No scatter radiation (measured value of 0.0 mrem min-1 [0.0 Sv min-1]; below minimum detectability of dosimeter) was detected underneath the lead aprons in the standing position and when sitting with the knees 25 cm apart, using all three types of lead. When sitting with the knees 10 cm apart, the mean dose equivalent rate of scatter radiation was higher using the half-skirt (0.01 mrem min-1 [0.000001 Sv min-1]) than the cross-back (below minimum detectability of dosimeter) and skirt aprons (below minimum detectability of dosimeter), but this did not reach statistical significance (p = 0.44). For all apron types and all positions, the use of an apron resulted in significantly less scatter radiation exposure when compared to no protection (p < 0.001). Protective lead aprons are effective at preventing testicular radiation exposure in both the standing and sitting positions. As the only detectable radiation exposure occurred with use of a half-skirt apron when sitting with the knees spread 10 cm apart, cross-back and full-skirt aprons may provide slightly enhanced protection over half-skirt aprons in the sitting position.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143994272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a Theranostics Center.","authors":"R P Harvey, Y Chen, O O Kuponiyi, J B Oleandi, E D Rinehart","doi":"10.1097/HP.0000000000001996","DOIUrl":"https://doi.org/10.1097/HP.0000000000001996","url":null,"abstract":"<p><strong>Abstract: </strong>Nuclear medicine radiopharmaceutical therapies or theranostics procedures may be performed in a number of environments within medical facilities. Some examples are having a dedicated room within a Nuclear Medicine Department, using inpatient units, clinics, or via a theranostics center. All methods may be regulatory compliant, effective, and advantageous depending on the medical facility's current environment. Organizations may consider designing, constructing, and implementing a freestanding theranostic center because of the potential advantages it can offer. A dedicated theranostic center can improve patient safety, care, and experience along with accommodation of increasing patient volumes, fiscal realities, and addition of new theranostic services that may be clinical or research in nature. Organizations are unique and the plausible benefits and applicability may be variable for different healthcare facilities.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144007994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparative Study on the Shielding Calculation Methods for an Optimal Shielding Design of Isolation Rooms in a Nuclear Medicine Facility in the Philippines Providing 131I Thyroid Ablation Therapy.","authors":"J M G F Gonzales, K M Romallosa-Dean, M E S K V Ramo, V K Parami","doi":"10.1097/HP.0000000000001988","DOIUrl":"https://doi.org/10.1097/HP.0000000000001988","url":null,"abstract":"<p><strong>Abstract: </strong>Iodine-131 (131I) has been used widely in diagnosing and treating thyroid disorders, but its radioactive nature poses risks of gamma radiation exposure to those near the patient. To mitigate this, radiation protection measures are needed, among which is the provision of optimal structural shielding. In the Philippines, achieving this involves using minimum shielding thickness to meet safety limits from national regulations. Widely used conventional methods, like those based on the tenth-value layer (TVLs) measurements, may yield poor estimates, while computational simulations are precise but impractical to use due to their complexity. Archer's fitting method offers a simple and accurate alternative for designing optimal shielding in medical imaging and radiotherapy facilities based on multiple studies. However, little to no data is available regarding the use of Archer's fitting method in providing better accuracy in shielding calculations in isolation rooms of 131I therapy facilities. A comparison of the transmission factors calculated using different calculation methods was done, and their effect on the minimum shielding thicknesses was investigated. Transmission curves generated with broad-beam TVLs reported from previous studies yielded the closest agreement with ANS/ANSI 6.4.3 buildup factors for lead barriers. On the other hand, results showed the closest agreement among the transmission curves and shielding thicknesses acquired with the American National Standard (ANSI/ANS) 6.4.3. buildup factors, Archer's fitting method, and Monte Carlo simulation through Particle Heavy Ion Transport System (PHITS) ver. 3.28 code for ordinary concrete barriers. Poor agreement was seen with the curves generated with the Narrow-Beam and Ideal Broad Beam TVL methods and the curve generated with ANSI/ANS 6.4.3. buildup factor data. Broad-Beam TVLs from previous studies, Monte Carlo Simulation, and Archer's fit can be alternative options for shielding design. An experimental study is proposed for verification.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143985193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Survey of Perception of Nuclear Radiation Risks among Teachers and Students around a Nuclear Power Plant in Liaoning Province, China.","authors":"Sitong Liu, Lu Sun, Cuiping Lei, Long Yuan, Yong Cui, Sumei Sun","doi":"10.1097/HP.0000000000001987","DOIUrl":"https://doi.org/10.1097/HP.0000000000001987","url":null,"abstract":"<p><strong>Abstract: </strong>To characterize awareness of radiation-related knowledge (RRK) and nuclear energy-related knowledge (NERK) among students and teachers living and working around nuclear power plants (NPPs), a survey of 546 teachers and students in two schools (one middle school and one high school) within 30 km of an NPP in Liaoning Province was conducted via paper questionnaires, web-based surveys, and face-to-face interviews. The data were entered using EpiData 3.1, and the result was analyzed using R Version 3.2.2. The analytical methods used included utilization and composition ratios, as well as mean-χ ± SD to statistically describe the data, and χ2 (Fisher's and Pearson's tests) as well as Student's t-test to draw comparisons. The results showed that the RRK and NERK scores (14 questions in total) of the teachers and students (546 individuals in total) were 75.6% and 57.4%, respectively. In the radiation knowledge section of the survey, the RRK of the students plus teachers was 67.8%, while the NERK score was 55.9%. The teachers' attitudes toward the benefits of nuclear energy was more positive, which may be attributable to their higher educational levels, their occupations, or their backgrounds. The survey results also indicated that teachers and students trusted nuclear science experts and authoritative media more than other non-authoritative media. This indicates that the ways in which relevant knowledge related to nuclear energy is disseminated should be carefully considered.</p>","PeriodicalId":12976,"journal":{"name":"Health physics","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143997703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}