Reduction In Exposure Research Articles

Modified poly-L-lysine for use as a clearing agent in pretargeted radioimmunotherapy

Abstract Background Pretargeted radioimmunotherapy of cancer has the potential to increase tumor specific uptake of activity when compared with conventional radioimmunotherapy. This is especially true in radioimmunotherapy with nuclides that exhibit a relatively short half-life. When administering antibody-based pretargeting molecules systemically, the antibodies often show a relatively slow clearance from the blood. Therefore, the use of a clearing agent is advantageous to remove unbound pretargeting molecules from the circulation, facilitating a reduction in the nonspecific radiation exposure to normal tissue while maximizing the dose delivered to the tumors. Results In the current study, two types of poly-L-lysine based clearing agents were produced for two different pretargeting systems: (strept)avidin/biotin and Tetrazine/Transcyclooctene. Poly-L-lysine was used as scaffold for production of clearing agents. The polymer is available in multiple sizes and can readily be modified with several functional groups, allowing different pretargeting strategies to be used. In vivo evaluation of the biotin-functionalized poly-L-lysine clearing agent, 110 repeating units, resulted in a decrease in blood concentration of the Iodine-125 labeled pretargeting agent of 50%, circa 23 h after injection, compared to controls. Two sizes, 68 and 143 repeating units, of the tetrazine-functionalized poly-L-lysine clearing agent were also evaluated, which at 23 h after injection decreased the blood concentration of the Iodine-125 labeled pretargeting agent to 58 and 38% respectively. Conclusion The straightforward synthesis of poly-L-lysine based clearing agents makes kit preparation possible and these agents show good potential for further evaluation, especially within the Tetrazine/Transcyclooctene pretargeting system where no liver or kidney accumulation was observed.

Minimising cybersecurity risk exposures in industrial control system environments: a techno-human vulnerability analysis approach

ABSTRACT Organisations operating IoT-enabled industrial control systems (ICSs) are concerned about growing cybersecurity risks and impacts to their systems. Cyber-attacks on ICSs demonstrate that technology alone is neither a problem nor a solution to the growing cybersecurity issues affecting these systems. As socio-technical systems, ICSs encompass the functions and interactions of social and technological system elements to enable and/or sustain industrial processes. Thus, a more effective cybersecurity risk management process needs to consider human and technology factors, especially for high-value industrial process targets. Combining critical reviews and gap analysis of existing vulnerability assessment methods with conceptual modelling, a Vulnerability Analysis Critical Impact Point Process (VACIP) methodology is proposed which considers both human and technological vulnerabilities within a cyber-physical system environment to inform an improved insight about attack criticality and impacts. VACIP is validated using a simulated industrial mini testbed; showing that it can enable practicable support for security vulnerability discovery, impact criticality analysis, weak link identification, and prioritised controls. Its novelty is demonstrated in its combination of technology and human vulnerability evaluations in the minimisation of system security exposures. It provides a useful guide for adopting effective cybersecurity risk assessment and exposure reduction strategies.

Indoor and ambient influences on PM2.5 exposure and well-being for a rail impacted community and implications for personal protections

Abstract Background
Higher air pollution concentrations can be observed near rail networks, local and highway automobile corridors, and shipyards. Communities adjacent to such sources are disproportionately exposed to air pollution from these stationary and mobile sources. One such community is West San Bernardino in California, where households are feet away from the Burlington Northern Santa Fe intermodal facility and are impacted by activities that are estimated to continuously emit air pollutants due to 24/7 operation.
Objective
This study aimed to (1) quantify the impact of personal mobility and housing characteristics on daily PM2.5 exposures and well-being for West San Bernardino community members, and (2) develop individualized resilience plans for community collaborators to support future PM2.5 exposure reduction. 
Methods
Personal PM2.5 exposures were measured for community collaborators for seven consecutive days during three deployment periods: October 2021, January 2022, and March 2022. Indoor and ambient PM2.5 levels were also continuously measured for five households over six months using PurpleAir Classic monitors. Demographic and well-being data were collected upon recruitment and after each week of engagement, respectively. 
Results
Personal exposures in home microenvironments were highest near the railyard and lower farthest away from the railyard. Home exposures were 40% higher on average compared to non-home microenvironments. Household PM2.5 had a higher-than-expected average infiltration factor of 0.55, and indoor 98th percentiles across the households far exceeded a healthy level at an average of 165 μg/m3. Resilience plans featured summaries of personal data and recommendations for mitigating exposures. 
Significance
Results suggest that surrounding land use and residential building characteristics compound to worsen air pollution exposures beyond what is expected for exposures in non-industrialized areas. Findings prompt a call for stronger regulation, not only for emissions, but also for indoor air quality and zoning standards that specifically protect disproportionately impacted communities.

Planned relocation may reduce communities’ future exposure to coastal inundation but effect varies with emission scenario and geography

The planned, permanent relocation of entire communities away from sea level rise (SLR) and coastal floods is an already occurring climate change adaptation strategy. Yet, planned relocations are fraught undertakings with multiple goals, and may or may not achieve their most basic objective: to reduce risk. Here we assess risk of future coastal flooding before and after moving, for three dates and three emissions scenarios, for 17 communities from a global dataset. Most communities achieved exposure reduction with less future inundation in destinations than origin sites, but the extent varies across time and emissions scenario. In all cases, origin sites have projected exposure to SLR plus a once-per-year flood, with increasing exposure under high emissions scenarios and towards 2100. In nine cases, even destination sites have projected inundation exposure under some scenarios. Small-island-to-small-island relocations had more projected inundation in destinations than moves from a small-island-to-mainland, or from mainland-to-mainland.

Pharmacometric Analysis to Describe Pharmacokinetics and Exposure-Efficacy Response of Ivermectin in Adolescents Infected with Trichuris trichiura.

The efficacy of the combination therapy of albendazole and ivermectin against Trichuris trichiura infection is higher in Tanzania than in Côte d'Ivoire. This study therefore aimed to investigate the difference between the population pharmacokinetics (PK) at these study sites and to determine if an exposure-response analysis could explain the low efficacy of the combination therapy in Côte d'Ivoire. Twenty-four participants (aged 12-19 years) receiving single doses of ivermectin (200 µg/kg) and albendazole (400 mg) were included in the population PK modeling. A regression analysis was performed to investigate the relationship between the reduction of fecal whipworm eggs and different exposure metrics (peak concentration, area under the plasma drug concentration-time curve [AUC], and time above a certain threshold). The PK profile of ivermectin was best described by a one-compartment model, first-order absorption, and no delay in absorption, with the absorption rate constant estimated as 0.26 per h, an apparent volume of distribution of 162.43 L, and an apparent clearance of 7.82 L/h. In Tanzania, all patients showed a very high reduction in egg count independent of exposure. In Côte d'Ivoire, a relationship was found between higher ivermectin exposure and egg reduction, although not statistically significant. There was no significant difference between the PK profiles at both study sites, despite a difference in clinical outcome. Model-based simulations indicate that higher ivermectin doses such as 400 and 600 µg/kg may be associated with reduced egg count. Larger clinical studies are warranted to explore further the exposure-efficacy response relationship at 200 µg/kg and higher ivermectin doses in adults and children.

Enhancing Air Quality Index Activity Guidelines for Preventing Cardiovascular Events in the General Adult Population

BackgroundThe public health relevance of daily Air Quality Index (AQI) activity guidelines for the general adult public in the United States to prevent atherosclerotic cardiovascular disease (ASCVD) events is questionable. ObjectivesThe purpose of the study was to explore the utility of a policy tailoring activity guidance to calculated ASCVD risk rather than uniform recommendations to the general adult public as currently provided. MethodsWe calculated the number needed to treat (NNT) to prevent one ASCVD event per day by following activity recommendations across 10-year ASCVD risk scores (1% to 20%). Second, we modeled the benefits of tailoring recommendations to ASCVD risk. ResultsThe NNT decreased as ASCVD risk and/or AQI levels increased. At AQIs up to 151 (68% of days with AQIs above moderate in the United States), the NNTs remained untenably high (>2.7-55.3 million) across ASCVD risk. Under unhealthy conditions (AQIs 151-200), 28% of elevated AQIs, NNTs <1 million could be achieved by current guidance (15% exposure reduction), but only among the highest-risk individuals (ASCVD 18% to 20%) on the most polluted days (AQIs 192-200). Tailoring guidance to ASCVD risk could yield NNTs <1 million at risk thresholds of 7.5% and 10% if activity restrictions were more stringent (35% to 50% exposure reductions) during unhealthy conditions. ConclusionsASCVD risk has a major influence on the NNT to prevent cardiovascular events by following AQI guidance. It may be possible for a future policy to improve the utility of AQI activity guidance for the general adult public by tailoring activity recommendations to ASCVD risk.

Early detection of neonatal sepsis and reduction of overall antibiotic exposure: Towards precision medicine

Infections claim the lives of over half a million newborns annually and expose survivors to the risk of lifelong disability. The challenge to clinicians is to identify newborns with invasive infections rapidly, promptly initiate antimicrobial treatment, and take measures to prevent and treat organ dysfunction. Moreover, excessive antibiotic use is a global public health problem. Despite considerable research on clinical and laboratory markers of neonatal sepsis, the effective translation into clinical practice remains limited. There is no single clinical or laboratory marker, nor any combination of markers that definitively confirms or rules out neonatal sepsis. The interpretation of these markers should take into account their diagnostic value for a given patient, along with their added value to the clinical decision-making process. The digitalization of health care systems, combined with increased computational power and advances in machine learning, offers the possibility of developing accurate predictive algorithms for early detection of neonatal sepsis.

Effectiveness of Sensors-Based Augmented Feedback in Ergonomics to Reduce Adverse Biomechanical Exposure in Work-Related Manual Handling—A Rapid Review of the Evidence

Manual handling is a major risk factor for work-related musculoskeletal disorders and one of the leading causes of disability-adjusted life years globally, necessitating multifaceted risk reduction measures. One potential intervention for manual handling tasks is work technique training assisted by augmented feedback on biomechanical exposures. However, there is a research gap regarding its effectiveness specifically for manual handling tasks in both real work environments and controlled settings, as well as its ability to induce retained reductions in biomechanical exposure. The gap was investigated using a rapid review comprising a literature search using two databases and 11 reviews/overviews to identify studies from the past 20 years, up to studies published by 1 June 2024. Sixteen studies were identified, with 14 of them being of high or moderate methodological quality and were included. Three studies were conducted in real work environments and eleven in controlled settings. Most studies (n = 9) used auditory feedback, followed by vibration feedback (n = 6). In real work environments, the evidence for the effectiveness of sensor-based augmented feedback in reducing biomechanical exposure during administration was considered to be inconsistent and very limited directly after administration. For longer periods after administration, ranging from one week to more than six months, there is currently no evidence demonstrating the effectiveness of the feedback. In controlled settings, there was strong evidence for its effectiveness during and immediately after administration, and limited evidence for effectiveness up to six months post-administration when considering the tasks included in the training. Future research needs are discussed.

Determining the Effectiveness of Interventions for the Reduction of Child Exposure to Traffic-Related Air Pollution at Schools in England

Traffic-related air pollution (TRAP) is a significant risk to human health and is particularly damaging to children as a vulnerable group. TRAP exposure near schools and on the school commute is linked to a growing number of adverse health effects, including respiratory and cardiovascular disease and can lead to (and exacerbate existing) respiratory conditions. The current study aimed to assess the effectiveness of interventions for the reduction of potential child exposure to TRAP at the school gates and on the school commute. This study employed dispersion modelling to assess the effects of interventions for reducing TRAP concentrations in the vicinity of five schools in England. The results revealed that all interventions led to reductions in nitrogen dioxide (NO2) concentrations. Improved travel routes were the most effective intervention for reducing concentrations along travel routes, while the introduction of low-emission zones (LEZs) proved most effective in reducing NO2 concentrations at schools, with greater effectiveness observed at shorter distances. Active travel also demonstrated effectiveness, particularly in areas with heavy traffic. When considering all receptors, LEZ implementation, active travel, and rideshare interventions exhibited effectiveness, with greater distance providing greater reductions in NO2 concentrations. Anti-idling was found to be more effective in sparsely populated areas. Combined with improved travel routes, anti-idling showed the greatest percentage difference in concentrations, followed by active travel, and rideshare.

Benefits of hypothetical air pollution reduction interventions on NCDs in Belgium

Abstract Background The adverse health impact of air pollution on non-communicable diseases (NCDs) is well documented, yet methodological tools for assessing the potential health benefits of interventions are lacking. This study uses a parametric g-computation approach to evaluate the impact of hypothetical interventions targeting long-term air pollution exposure on reducing NCDs prevalence in Belgium, using data from three national Health Interview Surveys (BHIS 2008-2013-2018). Methods BHIS data (n = 27,536) were linked to environmental data at participants’ residential addresses. A g-computation approach was used to calculate the potential impact fractions of air quality interventions on several NCDs. Regression models were adjusted for socio-economic, environmental and lifestyle factors. The scenarios involved reducing individual long-term air pollution exposure to WHO air quality guideline levels, followed by investigating dose-response functions through various percentage reductions in air pollution exposure. Results Significant associations were found between air pollution and asthma, stroke, and multimorbidity. Adhering to WHO air quality guidelines would substantially reduce stroke risk in Belgium by 0.87% (95% CI:0.38; 1.35) for PM2.5 and 0.32% (95% CI:-0.05; 0.70) for NO2, preventing 63% and 22% of cases, respectively. For asthma, risk reduction was 1.43% (95% CI:-0.53; 3.4) for PM2.5 and 0.83% (95% CI: 0.01; 1.63) for NO2, preventing 27% and 16% of cases, respectively. For multimorbidity, risk reduction was 3.20 % (95% CI: -1.75; 8.16) for PM2.5 and 0.43% (95% CI:-2.03; 2.90) for NO2, preventing 7% and 0.4% of cases, respectively. Results revealed a clear dose-response association between air pollution reduction and the prevalence of stroke, asthma, and multimorbidity in Belgium. Conclusions This study demonstrates that air pollution reduction interventions could effectively decrease the prevalence of asthma, stroke, and multimorbidity in Belgium. Key messages • Air pollution reduction interventions could effectively decrease the prevalence of asthma, stroke, and multimorbidity in Belgium. • The g-computation approach to assess PIF of interventions represents a straightforward approach for drawing causal inferences from observational data.

Assessment of controlled assistance from e-bikes as a mitigation strategy for individual PM exposure

Abstract Background While promoting active mobility and outdoor activities can benefit health (HLT), it also increases Exposure (EXP) to air pollutants, such as particulate matter (PM), due to the increased ventilation rate (VR) under physical activity. Traditional assessments of individual (IND) PM EXP involve costly equipment inaccessible to the public, but real-time low-cost sensors (LCS) are now emerging. This study presents a proof of concept to demonstrate the use of LCS for examining the real-time IND respiratory dose deposited (RDD) to PM cycling across the Brescia province. Methods An e-bike was ridden 33 times between 2022 and 2023 wearing a LCS for PM concentration [PM] linked to a GPS. Respiratory dose deposited(RDD) was calculated for six different locations within each route based on experimental PM and various VR. Results The LCS allows for the study of the spatial and temporal variability of [PM], revealing a significant difference (p &amp;lt; 0.01) according to the heating system operation and no significant difference (p &amp;gt; 0.05) depending on the location. RDD increases with [PM] and VR. Real-time and integrated RDD is calculated for routes with high (&amp;gt; 50 µg/m3), medium (25 µg/m3), and low (&amp;lt;10 µg/m3) [PM2.5]. The e-bike assistance is activated when the WHO interim target 4 of [PM] is reached to reduce VR, which corresponds to a shift to a lower physical activity intensity. The RDD calculated using the e-bike assistance over the path reduces RDD by about 23% and 11% over the high and medium [PM], while it never activates for the low [PM]. Conclusions This study demonstrates that the use of LCS allows the estimation of IND RDD, and the implementation of mitigation strategies based on controlled assistance from e-bikes would enable the reduction of PM individual EXP. Key messages • The integration of HLT data from wearable and air quality LCS enables the promotion of active mobility and outdoor activities controlling the EXP to air pollutants. • Establishing generalized guidelines based on this mitigation strategies for individual exposure reduction may also inform policy recommendations for promoting active and green mobility.

MANEJO DO SORRISO GENGIVAL ATRAVÉS DO USO DA TOXINA BOTULÍNICA TIPO A

An aesthetically pleasing smile results from the combination of several factors, such as the position, size, shape, and color of the teeth, as well as the exposure and characteristics of the gingival tissue. When evaluating the gingival tissue in a smile, several important factors must be considered: excessive vertical growth of the maxilla, reduced length of the upper lip, excessive contraction of the upper lip, and disproportion between the length and width of the clinical crown of the anterior teeth. A minimally invasive approach that can be used as a complement to dental treatment is the application of botulinum toxin, a neurotoxin produced by the anaerobic bacterium Clostridium botulinum. This toxin blocks the release of acetylcholine in the presynaptic vesicles of neuromuscular junctions, inhibiting muscle contraction. The aim of this literature review was to analyze the use of botulinum toxin type A (BTX-A) in the management of gummy smile. The search was conducted in the databases Google Scholar, PubMed, Latin American and Caribbean Health Sciences Literature (LILACS), and Scientific Electronic Library Online (SciELO). The descriptors used for the search were "botulinum toxin," "gingiva," "periodontology," and "dental aesthetics," combined using the boolean operators AND and OR. Although the evidence demonstrates favorable results, the use of botulinum toxin to correct gummy smile has limitations. It is a temporary solution, and patients should be informed about the need for periodic reapplications and the potential side effects, such as facial asymmetries. The reviewed studies indicate that this technique is particularly effective in cases of gummy smile resulting from hyperactivity of the upper lip elevator muscle, providing a significant reduction in gingival exposure, with results lasting up to 12 weeks. The combination of different therapeutic approaches, along with a careful evaluation of the causes of gummy smile, allows dental professionals to offer more integrated and personalized solutions for each patient.

Interactive Simulation of Nonpharmaceutical Interventions of Airborne Disease Transmission in Office Settings

The COVID-19 pandemic has caused major disruptions to workplace safety and productivity. A browser-based interactive disease transmission simulation was developed to enable managers and individuals (agents) to optimize safe office work activities during pandemic conditions. The application provides a user interface to evaluate the impact of non-pharmaceutical interventions (NPIs) policies on airborne disease exposure based on agents’ meeting patterns and room properties. Exposure is empirically calibrated using CO2 as a proxy for viral aerosol dispersion. For the building studied, the major findings are that the cubicles during low occupancy produce unexpectedly high exposure, upgrading meetings to larger rooms reduces total average exposure by 44%, and when all meetings are conducted in large rooms, a 79% exposure reduction is realized.

A Virtual Reality Approach to Overcome Glossophobia among University Students

In the contemporary academic landscape, university students frequently deliver presentations in front of their peers and faculty, often leading to heightened levels of Public Speaking Anxiety (PSA). This study explores the potential of Virtual Reality Exposure Therapy (VRET) to alleviate PSA among students. Our study introduces "Manch," a realistic VR environment that simulates classroom public speaking scenarios with lifelike audience interactions and a slide-deck presentation feature. The study was conducted with N=28 participants, showing a significant reduction in PSA levels post-VR exposure, thereby establishing VR's efficacy in mitigating PSA. Additionally, we also incorporated a unique qualitative analysis through participant interviews, offering deeper insights into individual experiences with VRET. Manch shows great promise as a tool for future studies and interventions aimed at reducing PSA, particularly among university students.

Extreme Heat and Air Quality: Community Leader Perspectives on Information Barriers and Opportunities in Two Environmental Justice Communities.

Extreme heat and air pollution exposure are leading causes of adverse cardiorespiratory health outcomes. Exposure reduction strategies are often focused at the local level. This study examined critical challenges community leaders face in understanding and sharing environmental exposure and health information. We conducted interviews with 19 community leaders of two urban environmental justice communities in Massachusetts, United States. Using directed content analysis, we examined air quality and heat perceptions, information and data resources, and barriers to understanding and communicating relevant local information. Participants shared concerns about both poor air quality and extreme heat. They also expressed the opinion that exposure risk information about these topics is siloed; heat and air quality data can be hard to access, interpret, and effectively communicate with community members. Solutions recommended by participants included community engagement, open-data portals, and creative science communication. Increasing sustainable collaborations among academic, government, healthcare, and nonprofit sectors is recommended.

Air quality improvement at urban bus stops: Optimal air purification placement using CFD

Nitrogen dioxide (NO2) levels are often elevated near roadways due to vehicle emissions, while sulfur dioxide (SO2) is predominantly found near petrochemical complexes as a result of industrial activities such as oil refining and chemical manufacturing. Considering the detrimental effects of these emissions on the environment and human health, the optimal placement of air purification systems at two bus stops in Ulsan, a heavily industrialized city in South Korea, was investigated in this study to reduce NO2 and SO2 concentrations. Computational fluid dynamics (CFD) simulations were performed to identify strategic installation locations, resulting in a significant reduction in pollutant levels. The largest impact was noted for the Deokha Market bus stop, whereby the added health risk (AR) decreased by 1.93 % and the exposure reduction effectiveness (ERE), a measure of air purification system efficiency, increased by 13.8 %. Similarly, at the Hyomun Intersection bus stop, placing the system near the sidewalk led to a significant reduction in AR by 1.60 % and an increase in ERE by 11.63 %. Additionally, air purification systems at Ulsan bus stops are expected to reduce NO2 levels by 9.1 ppb, decreasing mortality risk by 1.44 %, saving 7 lives annually, and yielding an economic benefit of 33.06 million USD.

Iodine Assessment of Carbon Dioxide Angiography in Iliac Branched Repair.

The objective of this study was to investigate whether the use of carbon dioxide (CO2) angiography decreases the intraoperative use of iodine contrast medium (ICM), thereby decreasing the risk of developing postoperative renal damage in patients undergoing iliac branch device (IBD) implantation. Patients undergoing IBD implantation at a single tertiary center between May 2013 and August 2019 were screened for inclusion in the study. A cohort of patients in whom an intraoperative imaging protocol using predominantly CO2 was compared with a control group in whom ICM was used (CO2 and ICM groups). Fusion imaging was used in both groups. Retrospective review of the medical charts and all imaging was performed. Variables were expressed as median with interquartile range (IQR) or absolute number and percentage. Wilcoxon-Mann-Whitney and χ2 tests were used to compare continuous and categorical variables, respectively. P values of <0 .05 were considered statistically significant. Twenty-three patients were included in the CO2 group and 21 in the ICM group without significant differences in patient characteristics between the groups. Intraoperative iodine exposure was lower in the CO2 group than in the ICM group (8.2 g [IQR, 7.1-10.9 g) vs 15.8 g (IQR 7.6-21 g); P = 0.015, respectively). There were no differences in technical success, clinical success, fluoroscopy time, and dose-area product in the 2 groups. There were no adverse events that could be related to the intraoperative use of CO2. There was no difference in postoperative survival nor renal function assessment between the groups despite the higher number of accessory renal arteries embolized in the CO2 group (P = 0.221). Reduction of intraoperative ICM exposure during IBD implantation is feasible through the predominant use of CO2 automated angiography. This can be done safely without affecting the technical success or radiation exposure. The immediate postoperative renal damage was low when a modern intraoperative imaging protocol with ICM was used and was not significantly reduced by the use of CO2. Further and larger studies are needed to investigate the long-term effects. This study aimed to investigate how to minimize intraoperative risk during iliac branched repair exploring the intraoperative use of automated carbon dioxide angiography in order to decrease the use of contrast media protecting renal function and thereby potentially impacting long-term survival.

First case report of a percutaneous coronary intervention with intracoronary lithotripsy in a heavily calcified and tortuous right coronary artery using the R-One+ robotic system

Abstract Background Advancement in interventional techniques has significantly improved the ability of percutaneous coronary intervention (PCI) to treat complex coronary artery disease. Despite these advancements, coronary artery calcification poses a substantial challenge during PCI, contributing to increased risks of procedural complications, prolonged procedure duration, an increase in radiation exposure dose for both patients and physicians. Recently, robotic PCI has emerged, allowing physicians to remotely control and deliver wires and catheters, leading to a notable reduction of the operator radiation exposure and a decrease in the risk of operator physical injuries such as back pain. Case summary We report the first robotic PCI with the R-One+™ robotic system using intracoronary lithotripsy for lesion preparation of two heavily calcified lesions in a tortuous right coronary artery of a 60-year old male patient followed by double drug-eluting stent implantation. Discussion Robotic PCI with the R-One+™ system can not only manage wires, balloons or stent systems but can also precisely position more bulky catheters such as intracoronary lithotripsy catheters to the target site even in the presence of a tortuous access.

Automated Injectors versus Manual Administration: A Comparative Analysis of Radiation Exposure Reduction in 18F-FDG Delivery

Abstract Background Despite the presence of safety protocols, the manual manipulation of radiopharmaceuticals continues to pose a significant occupational radiation risk. Health care professionals in nuclear medicine are at risk of radiation exposure, particularly to their hands and eyes. Despite existing protective measures, manual handling of radiopharmaceuticals remains a significant source of occupational radiation. Objective This study evaluates the effectiveness of automated injectors in reducing radiation exposure among health care workers during fluorine-18 fluorodeoxyglucose (18F-FDG) administrations, compared with traditional manual injection methods. Methods We assessed radiation exposure levels associated with manual versus automated 18F-FDG injection techniques using specialized dosimeters. Measurements focused on whole-body, extremity, and eye-lens radiation doses to evaluate the potential benefits of automation in minimizing exposure. Results Findings reveal that automated injectors significantly reduce radiation exposure, with decreases of 97.97 and 98.96% in left- and right-hand extremity doses, respectively, 43.24% in eye-lens dose, and 91.66% in whole-body dose compared with manual methods. Conclusion Automated injection systems offer considerable advantages in reducing health care worker radiation exposure in nuclear medicine. The substantial reduction in staff doses underscores the necessity of transitioning to such technology to promote safer clinical environments. This study highlights the critical role of automation in enhancing occupational safety standards within diagnostic radiology settings.

Deep-learning-based attenuation map generation in kidney single photon emission computed tomography

BackgroundAccurate attenuation correction (AC) is vital in nuclear medicine, particularly for quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) imaging. This study aimed to establish a CT-free quantification technology in kidney SPECT imaging using deep learning to generate synthetic attenuation maps (μ-maps) from SPECT data, thereby reducing radiation exposure and eliminating the need for CT scans.ResultsA dataset of 1000 Tc-99m DTPA SPECT/CT scans was analyzed for training (n = 800), validation (n = 100), and testing (n = 100) using a modified 3D U-Net for deep learning. The study investigated the use of primary emission and scattering SPECT data, normalization methods, loss function optimization, and up-sampling techniques for optimal μ-map generation. The problem of checkerboard artifacts, unique to μ-map generation from SPECT signals, and the effects of iodine contrast media were evaluated. The addition of scattering SPECT to primary emission SPECT imaging, logarithmic maximum normalization, the combination of absolute difference loss (L1) and three times the absolute gradient difference loss (3 × LGDL), and the nearest-neighbor interpolation significantly enhanced AI performance in μ-map generation (p < 0.00001). Checkerboard artifacts were effectively eliminated using the nearest-neighbor interpolation technique. The developed AI algorithm produced μ-maps neutral to the presence of iodine contrast and showed negligible contrast effects on quantitative SPECT measurement, such as glomerular filtration rate (GFR). The potential reduction in radiation exposure by transitioning to AI-based CT-free SPECT imaging ranges from 45.3 to 78.8%.ConclusionThe study successfully developed and optimized a deep learning algorithm for generating synthetic μ-maps in kidney SPECT images, demonstrating the potential to transition from conventional SPECT/CT to CT-free SPECT imaging for GFR measurement. This advancement represents a significant step towards enhancing patient safety and efficiency in nuclear medicine.