Metabolomics 2023 workshop report: moving toward consensus on best QA/QC practices in LC-MS-based untargeted metabolomics.

INTRODUCTION: During the Metabolomics 2023 conference, the Metabolomics Quality Assurance and Quality Control Consortium (mQACC) presented a QA/QC workshop for LC-MS-based untargeted metabolomics. OBJECTIVES: The Best Practices Working Group disseminated recent findings from community forums and discussed aspects to include in a living guidance document. METHODS: Presentations focused on reference materials, data quality review, metabolite identification/annotation and quality assurance. RESULTS: Live polling results and follow-up discussions offered a broad international perspective on QA/QC practices. CONCLUSIONS: Community input gathered from this workshop series is being used to shape the living guidance document, a continually evolving QA/QC best practices resource for metabolomics researchers.

Systematic review on the implementation of metrological assurance systems for medical devices in Latin America.

Background: Metrology plays a crucial role in small healthcare service businesses to ensure the quality of products and services. While legal metrology in healthcare exists in some regions, it lacks harmonization. In other countries, there is limited presence of metrology in medical and biomedical engineering. We aimed to evaluate the implementation of metrological assurance systems for medical devices in Latin America. Methods: A systematic review was conducted following PRISMA 2020 guidelines and registered with PROSPERO (CRD42022359284). Searches were performed across 13 databases from October 30th to November 3rd, 2022. The search equation was "(((quality assurance) AND (metrology)) AND (medical devices))." A total of 7,789 documents were identified, of which only 16 met the inclusion criteria. Results: The majority of studies (75%) were conducted in Colombia, with a significant portion being undergraduate theses. The primary normative references used in the analyzed studies were ISO 10012 and ISO 17025, with the majority (68.75%) relying on national legislation for their approach. One study in Colombia referenced eight standards, and one in Brazil analyzed user involvement in medical device management. Among the included studies, 56.25% were conducted in healthcare institutions, mainly clinics. Most studies provided implementation guidelines, with ISO 10012 being prominent, alongside ISO 17025, which implicitly addresses ISO 9001 elements. Global bias was low across all studies. Conclusion: Our results underscore the importance of metrological assurance in managing medical devices in Latin America. The utilization of international standards and national legislation illustrates the diverse approaches adopted by different institutions. Future research should focus on optimizing metrological practices to enhance quality and safety in healthcare.

The Performance of ChatGPT-4 and Gemini Ultra 1.0 for Quality Assurance Review in Emergency Medical Services Chest Pain Calls.

OBJECTIVES: This study assesses the feasibility, inter-rater reliability, and accuracy of using OpenAI's ChatGPT-4 and Google's Gemini Ultra large language models (LLMs), for Emergency Medical Services (EMS) quality assurance. The implementation of these LLMs for EMS quality assurance has the potential to significantly reduce the workload on medical directors and quality assurance staff by automating aspects of the processing and review of patient care reports. This offers the potential for more efficient and accurate and identification of areas requiring improvement, thereby potentially enhancing patient care outcomesMETHODS: Two expert human reviewers, ChatGPT GPT-4, and Gemini Ultra assessed and rated 150 consecutively sampled and anonymized prehospital records from 2 large urban EMS agencies for adherence to 2020 National Association of State EMS metrics for cardiac care. We evaluated the accuracy of scoring, inter-rater reliability, and review efficiency. The inter-rater reliability for the dichotomous outcome of each EMS metric was measured using the kappa statistic.RESULTS: Human reviewers showed high interrater reliability, with 91.2% agreement and a kappa coefficient, 0.782 (0.654-0.910). ChatGPT-4 achieved substantial agreement with human reviewers in EKG documentation and aspirin administration (76.2% agreement, kappa coefficient, 0.401 (0.334-0.468), but performance varied across other metrics. Gemini Ultra's evaluation was discontinued due to poor performance. No significant differences were observed in median review times: 01:28 minutes (IQR 1:12 - 1:51 min) per human chart review, 01:24 minutes (IQR 01:09 - 01:53 min) per ChatGPT-4 chart review (p = 0.46), and 01:50 minutes (IQR 01:10-03:34 min) per Gemini Ultra review (p = 0.06).CONCLUSIONS: Large language models demonstrate potential in supporting quality assurance by effectively and objectively extracting data elements. However, their accuracy in interpreting non-standardized and time-sensitive details remains inferior to human evaluators. Our findings suggest that current LLMs may best offer supplemental support to the human review processes, but their value remains limited. Enhancements in LLM training and integration are recommended for improved and more reliable performance in the quality assurance processes.

Clinical application of a GPU-accelerated monte carlo dose verification for cyberknife M6 with Iris collimator.

PURPOSE: To apply an independent GPU-accelerated Monte Carlo (MC) dose verification for CyberKnife M6 with Iris collimator and evaluate the dose calculation accuracy of RayTracing (TPS-RT) algorithm and Monte Carlo (TPS-MC) algorithm in the Precision treatment planning system (TPS). METHODS: GPU-accelerated MC algorithm (ArcherQA-CK) was integrated into a commercial dose verification system, ArcherQA, to implement the patient-specific quality assurance in the CyberKnife M6 system. 30 clinical cases (10 cases in head, and 10 cases in chest, and 10 cases in abdomen) were collected in this study. For each case, three different dose calculation methods (TPS-MC, TPS-RT and ArcherQA-CK) were implemented based on the same treatment plan and compared with each other. For evaluation, the 3D global gamma analysis and dose parameters of the target volume and organs at risk (OARs) were analyzed comparatively. RESULTS: For gamma pass rates at the criterion of 2%/2 mm, the results were over 98.0% for TPS-MC vs.TPS-RT, TPS-MC vs. ArcherQA-CK and TPS-RT vs. ArcherQA-CK in head cases, 84.9% for TPS-MC vs.TPS-RT, 98.0% for TPS-MC vs. ArcherQA-CK and 83.3% for TPS-RT vs. ArcherQA-CK in chest cases, 98.2% for TPS-MC vs.TPS-RT, 99.4% for TPS-MC vs. ArcherQA-CK and 94.5% for TPS-RT vs. ArcherQA-CK in abdomen cases. For dose parameters of planning target volume (PTV) in chest cases, the deviations of TPS-RT vs. TPS-MC and ArcherQA-CK vs. TPS-MC had significant difference (P < 0.01), and the deviations of TPS-RT vs. TPS-MC and TPS-RT vs. ArcherQA-CK were similar (P > 0.05). ArcherQA-CK had less calculation time compared with TPS-MC (1.66 min vs. 65.11 min). CONCLUSIONS: Our proposed MC dose engine (ArcherQA-CK) has a high degree of consistency with the Precision TPS-MC algorithm, which can quickly identify the calculation errors of TPS-RT algorithm for some chest cases. ArcherQA-CK can provide accurate patient-specific quality assurance in clinical practice.

Evaluation and improvement of the safety of 3D-printed template assisted intracavitary/interstitial brachytherapy for cervical cancer using repeat FMEA.

BACKGROUND AND PURPOSE: 3D-printed templates are used in intracavitary/interstitial brachytherapy (3DP-IC/IS) for locally advanced cervical cancer (LACC). We applied failure mode and effects analysis (FMEA) twice in one year to improve 3DP-IC/IS safety. MATERIALS AND METHODS: A risk assessment group was established. We created a process map for 3DP-IC/IS procedures, identifying potential failure modes (FMs) and evaluating occurrence (O), detectability (D), severity (S), and risk priority number (RPN = O*D*S). High RPN values identified high-risk FMs, and quality control (QC) methods were determined by root cause analysis. A second FMEA was performed a year later. RESULTS: The 3DP-IC/IS process included 10 main steps, 48 subprocesses, and 54 FMs. Initial RPN values ranged from 4.50 to 171.00 (median 50.50; average 52.18). Ten high-risk FMs were identified: (1) unreasonable needle track design (171.00/85.50), (2) noncoplanar needle label identification failure (126.00/64.00), (3) template model reconstruction failure (121.50/62.50), (4) improper gauze filling (112.00/60.25), (5) poor needle position (112.00/52.50). QC interventions lowered all high-risk RPN values during the second assessment. CONCLUSIONS: A feasible 3DP-IC/IS process was proposed. Staff training, automatic needle path planning, insertion guidance diagrams, template checking, system commissioning, and template design improvements effectively enhanced process safety.

Development and integration of a clinical dashboard within a dental school setting.

PURPOSE: To describe the development and integration of an electronic health record-driven, student dashboard that displays real-time data relative to the students' patient management and clinic experiences at the University of Illinois Chicago, College of Dentistry. MATERIALS AND METHODS: Following development and implementation of the student dashboard, various objective metrics were evaluated to identify any improvements in the clinical patient management. A cross-sectional retrospective chart review was completed of the electronic health record (axiUm, Exan, Coquitlam, BC, Canada) from January 2019 to April 2022 evaluating four performance metrics: student lockouts, note/code violations, overdue active patients, and overdue recall patients. Descriptive statistics were analyzed. The Kolmogorov-Smirnov test was applied to assess the normal distribution of data. Data were analyzed by the Kruskal-Wallis tests for potential differences between pre-dashboard and post-dashboard implementation years with the mean overdue active/recall patient to student ratio variables. Mann-Whitney U-tests for between-groups comparisons with Bonferroni correction for multiple comparisons were performed (α = 0.05). Descriptive statistics were performed to analyze the student utilization frequency of the dashboard. RESULTS: Post-implementation analysis indicated a slight decrease in the number of lockouts and note/code violation; and a statistically significant decrease in overdue active patients post-dashboard (P < 0.001). On average, students accessed their dashboards 3.3 times a week. CONCLUSIONS: Implementation of a student dashboard through the electronic health record platform within an academic dental practice has the potential to assist students with patient management and is utilized regularly by the students.

Novel strategies for the determination of plastic additives derived from agricultural plastics in soil using ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS).

Certain agricultural plastics, i.e., mulching films, are generally considered as potent sources of micro- and nanoplastics (MNPs), due to their direct application on soil and waste mishandling. During the synthesis and fabrication of such agricultural plastics, it is necessary to use chemicals, the so-called plastic additives (PAs), improving the physicochemical properties of the final polymeric product. However, since PAs are loosely bound on the polymer matrix, they can potentially leach into the soil environment with unidentified effects. Clearly, to monitor the fate of PAs in the terrestrial ecosystem, it is necessary to develop accurate, sensitive and robust analytical methods. To this end, a comprehensive analytical strategy was developed for monitoring 16 PAs with diverse physicochemical properties (partition coefficient; -3 < logP<19) in soil samples using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). For this purpose, two different extraction procedures were developed, namely, a single step ultrasound-assisted extraction (UAE) using ethyl acetate or an aqueous solution of methanol and a binary extraction, combining Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) and UAE principles with n-hexane as the extractant. Interestingly, within the sample preparation investigation, we identified in-lab contamination sources of PAs, e.g., centrifuge tubes or microfilters. Such consumables are made of plastic contaminating the procedural blanks and omitting their use was necessary to acquire satisfactory analytical performance. In detail, method validation was performed for 16 compounds achieving recoveries mainly in the range 70-120 %, repeatability (expressed as relative standard deviation, RSD %) < 20 % and limits of quantification (LOQs) ranging between 0.2 and 20 ng/g dry weight (dw). Importantly, the presented strategies are added to the very limited available for PA determination in soil, a topical issue with a significant and rather understudied impact on agriculture.

A nonparametric measure of contrast in x-ray images.

Objective We propose a nonparametric figure of merit, the contrast equivalent distance CED, to measure contrast directly from clinical images. Approach A relative brightness distance δ is calculated by making use of the order statistic of the pixel values. By multiplying δ with the grey value range R, the mean brightness distance MBD is obtained. From the MBD, the CED and the distance-to- noise ratio DNR can be derived. The latter is the ratio of the MBD and a previously suggested nonparametric measure τ for the noise. Since the order statistic is independent of the spatial arrangement of the pixel values, the measures can be obtained directly from clinical images. We apply the new measures to mammography images of an anthropomorphic phantom and of a phantom with a step wedge as well as to CT images of a head phantom. Main results For low-noise images of a step wedge, the MBD is equivalent to the conventional grey value distance. While this measure permits the evaluation of clinical images, it is sensitive to noise. Therefore, noise has to be quantified at the same time. When the ratio σ/τ of the noise standard deviation σ to τ is available, validity limits for the CED as a measure of contrast can be established. The new figures of merit can be calculated for entire images as well as on regions of interest (ROI) with an edge length not smaller than 32 px. Significance The new figures of merit are suited to quantify the quality of clinical images without relying on the assumption of a linear, shift-invariant system. They can be used for any kind of greyscale image, provided the ratio σ/τ can be estimated. This will hopefully help to achieve the optimisation of image quality vs dose required by radioprotection laws.

Nursing Home Star Ratings and End-Of-Life Care Quality: Lessons Learned From the Veterans Health Administration.

OBJECTIVES: More than 25% of deaths among older adults occur in nursing homes. Thus, assessments of nursing home quality, including the widely used 5-star rating systems, should reflect quality of end-of-life (EOL) care. Our objective was to examine the associations between Veterans Affairs (VA) nursing home star ratings and quality of EOL care as measured by the VA's Bereaved Family Survey (BFS). DESIGN: National, retrospective observational study. SETTING AND PARTICIPANTS: VA nursing homes, known as Community Living Centers (CLCs). All veterans who died in a CLC from October 2018 to September 2019 whose next of kin completed a BFS. METHODS: Using linked VA data sources, we examined the BFS-Performance Measure (BFS-PM) (ie, the % of BFS respondents who provided an "excellent" overall rating) by the Overall Star Rating and domain star ratings (unannounced survey, staffing, and quality) for the 133 CLCs in our sample. Logistic and linear regression was used to examine the associations between CLC Overall Star Rating and individual-level BFS outcomes. Outcomes included the BFS-PM (primary), the 3 BFS factor scores of Respectful Care and Communication, Emotional and Spiritual Support, and Death Benefits, and 2 symptom management items. RESULTS: Differences in the BFS-PM by CLC star rating were small to none and not statistically significant across all star rating domains. The relationship between a higher CLC Overall Star Rating and odds of an "excellent" BFS global rating was not statistically significant. Similarly, no significant associations were observed between a higher CLC Overall Star Rating and scores on the BFS factor scores and symptom management items. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that the current CLC star rating system is not sufficient to assess the quality of EOL care. BFS scores, or a comparative EOL quality of care measure, should be integrated into CLC quality rating systems.

Quality assessment of radiotherapy in the prospective randomized SENOMAC trial.

BACKGROUND AND PURPOSE: Recommendations for regional radiotherapy (RT) of sentinel lymph node (SLN)-positive breast cancer are debated. We here report a RT quality assessment of the SENOMAC trial. MATERIALS AND METHODS: The SENOMAC trial randomized clinically node-negative breast cancer patients with 1-2 SLN macrometastases to completion axillary lymph node dissection (cALND) or SLN biopsy only between 2015-2021. Adjuvant RT followed national guidelines. RT plans for patients included in Sweden and Denmark until June 2019 were collected (N = 1176) and compared to case report forms (CRF). Dose to level I (N = 270) and the humeral head (N = 321) was analyzed in detail. RESULTS: CRF-data and RT plans agreed in 99.3 % (breast/chest wall) and in 96.6 % of patients (regional RT). Congruence for whether level I was an intended RT target was lower (78 %). In accordance with Danish national guidelines, level I was more often an intended target in the SLN biopsy only arm (N = 334/611, 55 %,) than in the cALND arm (N = 174/565, 31 %,). When an intended target, level I received prescribed dose to 100 % (IQR 98-100 %) of the volume. However, even when not an intended target, full dose was delivered to > 80 % of level I (IQR 75-90 %). The intentional inclusion of level I in the target volume more than doubled the dose received by ≥ 50 % of the humeral head. CONCLUSION: Congruence between CRF data and RT plans was excellent. Level I received a high dose coverage even when not intentionally included in the target. Including level I in target significantly increased dose to the humeral head.

Longitudinal evaluation of an electronic audit and feedback system for patient safety in a large tertiary hospital setting.

Objective: This study sought to assess the impact of a novel electronic audit and feedback (e-A&F) system on patient outcomes. Methods: The e-A&F intervention was implemented in a tertiary hospital and involved near real-time feedback via web-based dashboards. We used a segmented regression analysis of interrupted time series. We modelled the pre-post change in outcomes for the (1) announcement of this priority list, and (2) implementation of the e-A&F intervention to have affected patient outcomes. Results: Across the study period there were 222,792 episodes of inpatient care, of which 13,904 episodes were found to contain one or more HACs, a risk of 6.24%. From the point of the first intervention until the end of the study the overall risk of a HAC reduced from 8.57% to 4.12% - a 51.93% reduction. Of this reduction the proportion attributed to each of these interventions was found to be 29.99% for the announcement of the priority list and 21.93% for the implementation of the e-A&F intervention. Discussion: Our findings lend evidence to a mechanism that the announcement of a measurement framework, at a national level, can lead to local strategies, such as e-A&F, that lead to significant continued improvements over time.

Treatment plan complexity quantification for predicting gamma passing rates in patient-specific quality assurance for stereotactic volumetric modulated arc therapy.

PURPOSE: To investigate the beam complexity of stereotactic Volumetric Modulated Arc Therapy (VMAT) plans quantitively and predict gamma passing rates (GPRs) using machine learning. METHODS: The entire dataset is exclusively made of stereotactic VMAT plans (301 plans with 594 beams) from Varian Edge LINAC. The GPRs were analyzed using Varian's portal dosimetry with 2%/2 mm criteria. A total of 27 metrics were calculated to investigate the correlation between metrics and GPRs. Random forest and gradient boosting models were developed and trained to predict the GPRs based on the extracted complexity features. The threshold values of complexity metric were obtained to predict a given beam to pass or fail from ROC curve analysis. RESULTS: The three moderately significant values of Spearman's rank correlation to GPRs were 0.508 (p < 0.001), 0.445 (p < 0.001), and -0.416 (p < 0.001) for proposed metric LAAM, the ratio of the average aperture area over jaw area (AAJA) and index of modulation, respectively. The random forest method achieved 98.74% prediction accuracy with mean absolute error of 1.23% using five-fold cross-validation, and 98.71% with 1.25% for gradient boosting regressor method, respectively. LAAM, leaf travelling distance (LT), AAJA, LT modulation complexity score (LTMCS) and index of modulation, were the top five most important complexity features. The LAAM metric showed the best performance with AUC value of 0.801, and threshold value of 0.365. CONCLUSIONS: The calculated metrics were effective in quantifying the complexity of stereotactic VMAT plans. We have demonstrated that the GPRs could be accurately predicted using machine learning methods based on extracted complexity metrics. The quantification of complexity and machine learning methods have the potential to improve stereotactic treatment planning and identify the failure of QA results promptly.

A survey of gamma camera and SPECT/CT quality control programs across a sample of public hospitals in Australia.

Performance testing of gamma cameras and single photon computed tomography/computed tomography (SPECT/CT) systems is not subject to regulatory requirements across states and territories in Australia. Internationally recognised testing standards from organisations such as the National Electrical Manufacturers Association (NEMA) describe methodologies for recommended tests. However, variations exist in suggested quality control (QC) schedules from professional bodies such as the Australia and New Zealand Society of Nuclear Medicine (ANZSNM). In this study, a survey was conducted to benchmark current QC programs across a selected sample of eight standalone and networked Australian public hospitals. Vendor-specific flood-field uniformity (intrinsic or extrinsic/system) verification without photomultiplier (PMT) tuning and CT QC were performed at all sites. Weekly and monthly PMT tuning followed by intrinsic flood-field verifications were performed at most sites. At least half of the sites performed monthly centre of rotation (COR) offset verifications. SPECT/CT alignment calibrations and verifications were undertaken by service engineers at all sites, and periodic verifications were performed by local staff at varying frequencies. Variations were observed for other periodic QC tests such as spatial resolution and planar sensitivity. Similarly, variations were observed for tests specific to whole-body systems and SPECT systems. Most sites checked daily and periodic QC results against pass/fail criteria set by vendors. Additional analyses of the QC results, including trend analysis and periodic reviews, were not common practice. The lack of regulatory requirements is likely to have led to variations in QC tests that are generally either harder to perform or are more labour intensive.

Radiotherapy Plan Quality Assurance in NRG Oncology Trials for Brain and Head/Neck Cancers: An AI-Enhanced Knowledge-Based Approach.

The quality of radiation therapy (RT) treatment plans directly affects the outcomes of clinical trials. KBP solutions have been utilized in RT plan quality assurance (QA). In this study, we evaluated the quality of RT plans for brain and head/neck cancers enrolled in multi-institutional clinical trials utilizing a KBP approach. The evaluation was conducted on 203 glioblastoma (GBM) patients enrolled in NRG-BN001 and 70 nasopharyngeal carcinoma (NPC) patients enrolled in NRG-HN001. For each trial, fifty high-quality photon plans were utilized to build a KBP photon model. A KBP proton model was generated using intensity-modulated proton therapy (IMPT) plans generated on 50 patients originally treated with photon RT. These models were then applied to generate KBP plans for the remaining patients, which were compared against the submitted plans for quality evaluation, including in terms of protocol compliance, target coverage, and organ-at-risk (OAR) doses. RT plans generated by the KBP models were demonstrated to have superior quality compared to the submitted plans. KBP IMPT plans can decrease the variation of proton plan quality and could possibly be used as a tool for developing improved plans in the future. Additionally, the KBP tool proved to be an effective instrument for RT plan QA in multi-center clinical trials.

An Optical Reusable 2D Radiochromic Gel-Based System for Ionising Radiation Measurements in Radiotherapy.

This work describes the development of a reusable 2D detector based on radiochromic reaction for radiotherapy dosimetric measurements. It consists of a radiochromic gel dosimeter in a cuboidal plastic container, scanning with a flatbed scanner, and data processing using a dedicated software package. This tool is assessed using the example of the application of the coincidence test of radiation and mechanical isocenters for a medical accelerator. The following were examined: scanning repeatability and image homogeneity, the impact of image processing on data processing in coincidence tests, and irradiation conditions-monitor units per radiation beam and irradiation field are selected. Optimal conditions for carrying out the test are chosen: (i) the multi-leaf collimator gap should preferably be 5 mm for 2D star shot irradiation, (ii) it is recommended to apply ≥2500-≤5000 MU per beam to obtain a strong signal enabling easy data processing, (iii) Mean filter can be applied to the images to improve calculations. An approach to dosimeter reuse with the goal of reducing costs is presented; the number of reuses is related to the MUs per beam, which, in this study, is about 5-57 for 30,000-2500 MU per beam (four fields). The proposed reusable system was successfully applied to the coincidence tests, confirming its suitability as a new potential quality assurance tool in radiotherapy.

External Quality Assessment (EQA) for SARS-CoV-2 RNA Point-of-Care Testing in Primary Healthcare Services: Analytical Performance over Seven EQA Cycles.

In April 2020, the Aboriginal and Torres Strait Islander COVID-19 Point-of-Care (POC) Testing Program was initiated to improve access to rapid molecular-based SARS-CoV-2 detection in First Nations communities. At capacity, the program reached 105 health services across Australia. An external review estimated the program contributed to averting between 23,000 and 122,000 COVID-19 infections within 40 days of the first infection in a remote community, equating to cost savings of between AU$337 million and AU$1.8 billion. Essential to the quality management of this program, a customised External Quality Assessment (EQA) program was developed with the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP). From July 2020 to May 2022, SARS-CoV-2 EQA participation ranged from 93 to 100%. Overall concordance of valid EQA results was high (98%), with improved performance following the first survey. These results are consistent with those reported by 12 Australian and 4 New Zealand laboratories for three SARS-CoV-2 RNA EQA surveys in March 2020, demonstrating that SARS-CoV-2 RNA POC testing in primary care settings can be performed to an equivalent laboratory analytical standard. More broadly, this study highlights the value of quality management practices in real-world testing environments and the benefits of ongoing EQA program participation.

Practitioner dashboard feedback improves glycemic but not temperature compliance during cardiac surgery: A single center retrospective analysis.

STUDY OBJECTIVE: To determine the association of practitioner dashboard feedback of intraoperative glycemic and temperature control on maintenance of normoglycemia and normothermia. DESIGN: Retrospective review. SETTING: Single tertiary care institution. PATIENTS: Patients over the age of 18 undergoing cardiac surgery from February 17, 2021 through February 16, 2023. During the study interval, 15 anesthesiologists providing care during 2255 procedures were analyzed: 1114 prior to the individual faculty dashboard distribution and 1141 after commencement of dashboard distribution. INTERVENTIONS: On February 17, 2022, anesthesia faculty members began receiving monthly individualized dashboards indicating their personal intraoperative glycemic and temperature compliance rates. MEASUREMENTS: Baseline patient demographic characteristics, surgical and cardiopulmonary bypass times, perioperative temperature and glucose concentrations, and the incidence of sternal wound infections. Glycemic compliance was defined as final serum glucose between 80 and 180 mg/dL. Temperature compliance was defined as an average temperature during the final 30 min of the surgical procedure between 35 and 37.3 °C inclusive. MAIN RESULTS: Dashboard distribution was associated with a significant decrease in the average glucose concentration (median location shift by -6 mg% (95% confidence interval (CI) -8, -4), p < 0.001) from 157 mg/dL to 152 mg/dL and final glucose concentration (median location shift by -17 mg/dL (95% CI -19, -14, p < 0.001) from 161 mg/dL to 145 mg/dL. The intervention was associated with an improvement in glycemic compliance from 71.4% to 87.1% (odds ratio (OR): 2.71(95% CI 2.19, 3.37, p < 0.001)). There were no significant differences in final temperature (36.3 °C [Q1, Q3: 36.0, 36.6] vs. 36.3 °C [Q1, Q3: 36.0, 36.7] (p = 0.232)) with the intervention nor were there any statistically significant differences in temperature compliance (93.9% vs. 92.9%, OR: 0.79 (95% CI 0.55-1.14, p = 0.25). There were no statistically significant changes in the incidence of superficial, deep, or any wound infections with the intervention. CONCLUSIONS: Individualized practitioner dashboard distribution may be an effective tool to increase intraoperative glycemic control.

Proton beam spot size and position measurements using a multi-strip ionization chamber.

PURPOSE: To develop and characterize a large-area multi-strip ionization chamber (MSIC) for efficient measurement of proton beam spot size and position at a synchrotron-based proton therapy facility. METHODS AND MATERIALS: A 420 mm x 320 mm MSIC was designed with 240 vertical strips and 180 horizontal strips at 1.75 mm pitch. The MSIC was characterized by irradiating a grid of proton spots across 17 energies from 73.5 MeV to 235 MeV and comparing to simultaneous measurements made with a reference Gafchromic EBT3 film. Beam profiles, spot sizes, and positions were analyzed. Short term measurement stability and sensitivity were evaluated. RESULTS: Excellent agreement was demonstrated between the MSIC and EBT3 film for both spot size and position measurements. Spot sizes agreed within ± 0.18 mm for all energies tested. Measured beam spot positions agreed within ± 0.17 mm. The detector showed good short term measurement stability and low noise performance. CONCLUSION: The large-area MSIC enables efficient and accurate proton beam spot characterization across the clinical energy range. The results indicate the MSIC is suitable for pencil beam scanning proton therapy commissioning and quality assurance applications requiring fast spot size and position quantification.

Small field measurements using electronic portal imaging device.

Purpose/Objective Small-field measurement poses challenges. Although many high-resolution detectors are commercially available, the EPID for small-field dosimetry remains underexplored. This study aimed to evaluate the performance of EPID for small-field measurements and to derive tailored correction factors for precise small-field dosimetry verification. Material/Methods Six high-resolution radiation detectors, including W2 and W1 plastic scintillators, Edge-detector, microSilicon, microDiamond and EPID were utilized. The output factors, depth doses and profiles, were measured for various beam energies (6 MV-FF, 6 MV-FFF, 10 MV-FF, and 10 MV-FFF) and field sizes (10 x 10 cm2, 5 x 5 cm2, 4 x 4 cm2, 3 x 3 cm2, 2 x 2 cm2, 1 x 1 cm2, 0.5 x 0.5 cm2) using a Varian Truebeam linear accelerator. During measurements, acrylic plates of appropriate depth were placed on the EPID, while a 3D water tank was used with five-point detectors. EPID measured data were compared with W2 plastic scintillator and measurements from other high-resolution detectors. The analysis included percentage deviations in output factors, differences in percentage for PDD and for the profiles, FWHM, maximum difference in the flat region, penumbra, and 1D gamma were analyzed. The output factor and depth dose ratios were fitted using exponential functions and fractional polynomial fitting in STATA 16.2, with W2 scintillator as reference, and corresponding formulae were obtained. The established correction factors were validated using two Truebeam machines. Results When comparing EPID and W2-PSD across all field-sizes and energies, the deviation for output factors ranged from 1% to 15%. Depth doses, the percentage difference beyond dmax ranged from 1% to 19%. For profiles, maximum of 4% was observed in the 100% - 80% region. The correction factor formulae were validated with two independent EPIDs and closely matched within 3%. Conclusion EPID can effectively serve as small-field dosimetry verification tool with appropriate correction factors.