Physics in medicine and biology最新文献

{"title":"Investigating radical yield variations in FLASH and conventional proton irradiation via microscopic Monte Carlo simulations.","authors":"Yuting Peng, Youfang Lai, Lingshu Yin, Yujie Chi, Heng Li, Xun Jia","doi":"10.1088/1361-6560/add07b","DOIUrl":"https://doi.org/10.1088/1361-6560/add07b","url":null,"abstract":"<p><p><i>Objective.</i>Ultra-high-dose rate (UHDR) FLASH radiation therapy has shown remarkable tissue sparing effects compared to that at conventional dose rates (CDR). Radical production modulated by dose rate is expected to be one of the factors triggering different radiobiological responses. This study investigates the impacts of dose rate on radical yields in UHDR FLASH and CDR proton irradiation via GPU-based microscopic Monte Carlo (MC) simulations.<i>Approach.</i>We considered a region of interest (ROI) irradiated by a proton beam produced with a synchrotron pulse structure. The number of protons entering into the ROI was estimated in UHDR and CDR conditions. We sampled protons entering the ROI with randomly distributed spatial and temporal positions. An in-house developed GPU-based microscopic MC simulation package was used to model radiation physics and chemical processes with a periodic boundary condition. The temporal evolution of the radical yields was computed for different radical types, which in this work are hydrated electroneh, hydroxyl⋅OH, hydrogen radicalH⋅and hydrogen peroxideH2O2. We also examined radical yields with different proton energies from 1 to 142.4 MeV.<i>Main results.</i>Under the UHDR FLASH conditions, radical production was altered as a result of the spatial and temporal overlap of radicals produced by different protons, causing a change in their interactions. For the case with 142.4 MeV protons after 50 micropulses, the chemical yield of⋅OHunder the FLASH scheme was decreased by ∼14% compared with that under the CDR condition. The percentage of reduction increased with the number of micropulses and decreased with proton energy.<i>Significance.</i>We modeled microscopic phenomena of radiation physics and chemistry triggered by synchrotron proton irradiation under UHDR FLASH and CDR conditions. Our results provided insights into the underlying mechanisms responsible for the FLASH effect.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12067973/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143988628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extending TOPAS with an analytical microdosimetric function: application and benchmarking with nBio track structure simulations.","authors":"Shannon Hartzell, Alessio Parisi, Tatsuhiko Sato, Chris J Beltran, Keith M Furutani","doi":"10.1088/1361-6560/adcfec","DOIUrl":"https://doi.org/10.1088/1361-6560/adcfec","url":null,"abstract":"<p><p>Microdosimetric distributions are important to accurately describe the biological impact of ionizing radiation, particularly in ion therapy. The computational demands of track structure simulations, a gold standard for modeling microscopic energy deposition, limit their practicality for large-scale or clinical applications. The analytical microdosimetric function (AMF) is a computationally efficient function that reproduces track structure simulation results. First introduced in the particle and heavy ion transport code system Monte Carlo code in 2006 and updated in 2023, the AMF offers a promising alternative for calculating microdosimetric spectra. This study implements the AMF within the Geant4-based Tool for Particle Therapy (TOPAS) platform, enabling efficient calculation of microdosimetric spectra and radiobiological metrics, including dose-mean lineal energy (y¯D) and relative biological effectiveness (RBE) using clinically relevant models, including the modified microdosimetric kinetic model and Mayo Clinic Florida MKM. Using OpenTOPAS (v4.0.0), the AMF extension was benchmarked against TOPAS-nBio track structure simulations for ions relevant to radiotherapy and space applications (¹H,⁴He,⁷Li,¹²C,¹⁶O,²⁰Ne,⁴⁰Ar,⁵⁶Fe). AMF results were further compared with TOPAS-nBio at different depths within the mixed radiation field of a carbon spread-out Bragg peak (SOBP). The AMF extension demonstrated reasonable agreement with TOPAS-nBio track structure simulations for most ions and energies. Microdosimetric spectra and derived metrics,y¯Dand RBE, showed average discrepancies under 10% for most cases. Deviations were largely attributed to differences in Monte Carlo stopping power models and ionization cross-sections. In an SOBP, the RBE calculated using TOPAS-nBio and AMF consistently agreed within 5%. Additionally, the AMF achieved significant computational efficiency, reducing simulation times by over 98% compared to TOPAS-nBio at discrete depths in an SOBP. The AMF extension in TOPAS provides a computationally efficient alternative to track structure simulations for microdosimetric analysis and RBE modeling. Its integration with advanced RBE models enables rapid, accurate calculations critical for particle therapy research and clinical treatment planning.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144049146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the hysteresis loss in magnetic nanoparticles by magnetic particle spectroscopy.","authors":"Samuel Goegebeur, Katrijn Everaert, Patricia Radon, James Wells, Norbert Löwa, Annelies Coene, Frank Wiekhorst, Jonathan Leliaert","doi":"10.1088/1361-6560/add07e","DOIUrl":"https://doi.org/10.1088/1361-6560/add07e","url":null,"abstract":"<p><p><i>Objective<u>.</u></i>Magnetic fluid hyperthermia is a promising adjuvant cancer therapy presently approaching clinical application. The therapeutic effect stems from the heat produced by magnetic nanoparticles (MNPs) administered to the tumor site and exposed to an AC magnetic field applied from outside the body. The objective of our study is to improve the integration of magnetic particle imaging (MPI) and hyperthermia as a theranostic application by allowing a real-time monitoring of local heat generation.<i>Approach.</i>The area of the dynamic hysteresis loop of the MNP is a measure of the heat produced by the MNP. However, depending on the specifics of the measurements, an accurate determination of the dynamic hysteresis loop of MNPs by conventional magnetic particle spectroscopy (MPS) can be hindered due to missing information of the first harmonic. The method presented in this work provides a solution to this problem by extracting the area of the hysteresis loop from measured MPS spectra through the reconstruction of the first harmonic.<i>Main results.</i>The method was tested on three distinct commercial MNP systems and found to be in good agreement with hysteresis loops directly obtained through AC magnetometry, confirming the method's reliability.<i>Significance.</i>This advancement enables accurate real-time monitoring of the energy dissipated as heat by the particles during MPS measurements and thus directly contributes to the development of MPI-guided hyperthermia.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143976952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A biological optimization method for carbon therapy via iterative Jacobian-based linearization.","authors":"Chao Wang, Ya-Nan Zhu, Wangyao Li, Yuting Lin, Hao Gao","doi":"10.1088/1361-6560/add104","DOIUrl":"https://doi.org/10.1088/1361-6560/add104","url":null,"abstract":"<p><p><i>Objective.</i>Carbon ion radiotherapy (CIRT) can provide higher biological effectiveness and cause more damage to cancer cells compared to photon or proton radiotherapy, especially for radio-resistant tumors. The optimization of biological dose is essential for CIRT, to achieve the desirable tumoricidal dose while mitigating biological damage to normal tissues and organs at risk (OAR). However, the biological optimization for CIRT is mathematically challenging, due to the nonlinear nature of biological dose model, which can lead to computational inaccuracy and inefficiency. This work will develop an accurate and efficient biological optimization method for CIRT.<i>Approach.</i>The proposed method is called iterative Jacobian-based linearization (IJL). In IJL, the biological dose is modeled as the product of the physical dose and relative biological effect, which is based on the linear-quadratic model via the local effect model in this work, and the optimization objective consists of dose-volume histogram based biological dose objectives within clinical target volume and OAR. The optimization algorithm for IJL is through iterative convex relaxation, in which the nonlinear biological dose is iteratively linearized using Jacobian-based approximations and the linear subproblems are solved using alternating direction method of multipliers. To compare with IJL, the limited-memory quasi-Newton (QN) method (limited-memory version) is developed that directly solves the same nonlinear biological optimization problem.<i>Main results.</i>Compared to the QN, IJL demonstrated superior plan accuracy, e.g. better OAR sparing with the reduction of biological dose in the CTV-surrounding volume (PTV1cm) to 89.7%, 95.0%, 88.3% for brain, lung, and abdomen, respectively; IJL also had higher computational efficiency, with approximately 1/10 the computational time per iteration and continuously decreasing objectives (while being stagnated for QN after certain number of iterations).<i>Significance.</i>A novel optimization algorithm, IJL, incorporating iterative linearization of biological dose, is proposed to accurately and efficiently solve the biological optimization problem for CIRT. It demonstrates superior plan accuracy and computational efficiency compared to the direct nonlinear QN optimization method.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implementation of a proton FLASH platform for pre-clinical studies using a gantry-mounted synchrocyclotron.","authors":"Arash Darafsheh, Anissa Bey","doi":"10.1088/1361-6560/add106","DOIUrl":"https://doi.org/10.1088/1361-6560/add106","url":null,"abstract":"<p><p><i>Objective</i>. External beam radiation therapy (RT) at ultra-high dose rate (FLASH RT) has shown promise for improving the therapeutic ratio; exploiting its full potential, however, requires systematic preclinical studies to unravel the underlying radiobiological mechanisms. We demonstrate a proton irradiation platform for pre-clinical FLASH studies using a gantry-mounted proton therapy system in clinical operation.<i>Approach</i>. An accessory comprising a transmission ionization chamber, a tray accommodating beam modifying elements, including range shifting blocks made of boron carbide (B₄C) and poly(methyl methacrylate) (PMMA), and brass apertures to shape the beam's lateral extent was attached to the nozzle. A range modulator composed of arrays of holes drilled in a PMMA slab was used to form a spread-out Bragg peak (SOBP). The integral depth dose (IDD) curves, lateral dose profiles, and dose rate were measured using existing dosimeters for different beam modifying material combinations.<i>Results</i>. The range modulator allowed achieving an SOBP with 14 mm modulation. The proton range was gradually reduced through adding B₄C and PMMA blocks in the beamline, while the beam spot's size gradually increased and became more symmetric as protons traveled through more material. The commercial scintillator screen showed a dose-rate-independent response for measuring lateral dose profiles. The representative IDDs of the FLASH beam can be measured with a commercial multilayer ionization chamber device at a low dose rate since the IDD did not depend on the dose rate.<i>Significance</i>. This work demonstrated a platform for delivering ∼70 Gy s^-1SOBP proton FLASH beams using a gantry-mounted synchrocyclotron clinical system. We showed the evolution of an asymmetric and small single proton spot to a more symmetric and larger spot after ranging and shaping through different components. Using dosimeters commonly employed for quality assurance purposes, we report an efficient method for the characterization of proton FLASH beams.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12056584/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144063979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A systematic characterization of plastic scintillation dosimeters response in magnetic fields: II. Monte Carlo simulations.","authors":"Yunuen Cervantes, Simon Lambert-Girard, Ilias Billas, François Therriault-Proulx, Hugo Bouchard, Louis Archambault, Luc Beaulieu","doi":"10.1088/1361-6560/add1a8","DOIUrl":"https://doi.org/10.1088/1361-6560/add1a8","url":null,"abstract":"<p><p><i>Purpose.</i>This study aims to investigate and validate the response of plastic scintillation dosimeters (PSDs) in the presence of magnetic fields using Monte Carlo simulations, focusing on the accuracy of electron fluence, dose calculations, and the optical processes of scintillation and Cherenkov radiation.<i>Methods.</i>Monte Carlo simulations, using EGSnrc and TOPAS, of the PSD response under magnetic fields were performed. First, electron fluence simulations were conducted with three different physics listsg4em-penelope,g4em-standard_opt3andg4em-standard_opt4, with the goal of benchmarking their performance in magnetic fields. Secondly, a Fano test for dose calculations was performed using only theg4em-penelopephysics list. Thirdly, the Cherenkov process under magnetic fields was validated against theoretical predictions. Finally, a PSD probe was modeled and simulated, with results compared against measurements.<i>Results.</i>Theg4em-penelopephysics list demonstrated a most balanced performance, showing the closest agreement with EGSnrc simulations and lower variability in magnetic fields thang4em-standard_opt4. Fano test results showed an accuracy of at least 0.36% for dose calculations. Simulations of Cherenkov radiation in ideal conditions were in agreement with theoretical predictions at both 0 T and 1.5 T. Monte Carlo simulations successfully reproduced experimental trends for Cherenkov radiation under magnetic fields. However, discrepancies were found, with deviations of up to 7.7% when electrons were deflected towards the tip and up to 21.0% in the opposite direction, likely due to modeling limitations. A key result is that Monte Carlo simulations of the scintillation process in magnetic fields failed to reproduce experimental observations. While experimental results showed a significant effect of magnetic fields on scintillation yield, the simulations did not reflect this behavior.<i>Conclusion.</i>This study establishes that TOPAS, specifically using theg4em-penelopephysics list, is a reliable tool for simulating dose, electron fluence, and Cherenkov radiation in the presence of magnetic fields. However, significant discrepancies were observed in the scintillation processes, where Monte Carlo simulations failed to reproduce the effect of magnetic fields seen in experimental measurements. These findings point out the need for further refinement of simulation models, particularly in accurately representing scintillation under magnetic fields.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144015662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A systematic characterization of plastic scintillation dosimeters response in magnetic fields: I. Experimental measurements.","authors":"Yunuen Cervantes, Simon Lambert-Girard, Ilias Billas, François Therriault-Proulx, Hugo Bouchard, Louis Archambault, Luc Beaulieu","doi":"10.1088/1361-6560/add1a7","DOIUrl":"https://doi.org/10.1088/1361-6560/add1a7","url":null,"abstract":"<p><p><i>Objective.</i>This study aims to evaluate the performance of five distinct plastic scintillation dosimeters (PSDs) in magnetic fields, as well as to validate the accuracy of the hyperspectral approach for stem-effect correction. The effect of the magnetic field on different base core materials and components within the PSDs was also investigated, as well as the effect of field size and orientation.<i>Approach.</i>Each PSD was placed at 5 cm depth in a water tank inside an electromagnet gap. Magnetic fields, between 0 and 1.5 T, were set to be perpendicular to the 6 MeV photon beam and to the PSD axis. The detector axis was either parallel or perpendicular to the photon beam. Different field sizes were used. The hyperspectral technique was validated and used to determine the scintillation, fluorescence and Cherenkov components at different magnetic fields.<i>Main results.</i>The hyperspectral method accurately removes stem effects in magnetic fields, even when calibration is performed at 0 T. The stem light yield shows good agreement with clear fiber measurements, with relative differences within 2.0%. In the parallel orientation, the corrected PSD response is highly symmetric relative to magnetic field polarity, with a maximum variation of only 0.2% from unity. Scintillation light yield increases with magnetic field by 3.6%-6.25% depending on PSD properties. Cherenkov light yield varies up to 230% and down to 0.30% of the 0 T value, depending on magnetic field polarity. The impact of magnetic fields depends primarily on the properties of the scintillator itself, with polyvinyltoluene-based probes showing greater sensitivity than polystyrene-based probes. The inclusion of a wavelength shifter has minimal on the magnetic field's effect on scintillation light yield. Normalized scintillation light yield decreases with smaller field sizes.<i>Significance.</i>PSDs are well-suited for accurate dosimetry in magnetic fields, provided that accurate stem-effect correction techniques are applied. The scintillator properties play a significant role in determining the PSD's sensitivity to magnetic fields. The hyperspectral method is a robust approach for accurate stem-effect removal in such conditions.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144050146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Range uncertainty reductions in proton therapy and resulting improvements in quality-adjusted life expectancy (QALE) for head-and-neck cancer patients.","authors":"Sebastian Tattenberg, Peilin Liu, Anthony Mulhem, Xiaoda Cong, Christopher Thome, Cornelia Hoehr, Xuanfeng Ding","doi":"10.1088/1361-6560/add07d","DOIUrl":"https://doi.org/10.1088/1361-6560/add07d","url":null,"abstract":"<p><p><i>Objective</i>. Due to higher dose conformality to the target, proton radiotherapy for cancer has received rapidly-growing interest. However, uncertainties in the<i>in vivo</i>proton range and methods to reduce them remain active areas of research. Based on 20 patients with head-and-neck cancer, this study aims to quantify the benefits of proton range uncertainty reductions in terms of the resulting improvements in quality-adjusted life expectancy (QALE).<i>Approach</i>. For each patient, two different proton therapy treatment plans were created, which assumed a current clinical range uncertainty of approximately 3.5% (IMPT_3.5%) and a potentially achievable range uncertainty of 1.0% (IMPT_1%). A Markov model considering the probability of tumor control and the development of xerostomia, larynx edema, secondary cancer, and/or metastases as well as death from primary cancer, secondary cancer, metastases, or unrelated causes was constructed, and for every patient and treatment plan, 10 000 simulations of the patient's entire lifetime from the time of treatment until death were performed.<i>Main results.</i>A 3.5%-1% range uncertainty reduction increased QALE by up to 0.4 quality-adjusted life years (QALYs) in the nominal and up to 0.6 QALY in the worst-case scenario, equivalent to 4.8 months and 7.2 months of life in perfect health. This was largely the result of a reduction in healthy tissue toxicity rates, which were reduced by up to 8.5 percentage points (pp) and 10.0 pp in the nominal and worst-case scenario, respectively.<i>Significance</i>. The benefits of a 3.5%-1% range uncertainty reduction in 20 patients with head-and-neck cancer were quantified in terms of the associated improvement in QALE. The highest QALE improvements were observed in patients in the top quartile of youngest patients at the time of treatment, due to the longer potential lifespan over which prevented healthy tissue toxicities would have impacted the patients' quality of life.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144015760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel transfer learning framework for non-uniform conductivity estimation with limited data in personalized brain stimulation.","authors":"Yoshiki Kubota, Sachiko Kodera, Akimasa Hirata","doi":"10.1088/1361-6560/add105","DOIUrl":"https://doi.org/10.1088/1361-6560/add105","url":null,"abstract":"<p><p><i>Objective</i>. Personalized transcranial magnetic stimulation (TMS) requires individualized head models that incorporate non-uniform conductivity to enable target-specific stimulation. Accurately estimating non-uniform conductivity in individualized head models remains a challenge due to the difficulty of obtaining precise ground truth data. To address this issue, we have developed a novel transfer learning-based approach for automatically estimating non-uniform conductivity in a human head model with limited data.<i>Approach</i>. The proposed method complements the limitations of the previous conductivity network (CondNet) and improves the conductivity estimation accuracy. This method generates a segmentation model from T1- and T2-weighted magnetic resonance images, which is then used for conductivity estimation via transfer learning. To enhance the model's representation capability, a Transformer was incorporated into the segmentation model, while the conductivity estimation model was designed using a combination of Attention Gates and Residual Connections, enabling efficient learning even with a small amount of data.<i>Main results</i>. The proposed method was evaluated using 1494 images, demonstrating a 2.4% improvement in segmentation accuracy and a 29.1% increase in conductivity estimation accuracy compared with CondNet. Furthermore, the proposed method achieved superior conductivity estimation accuracy even with only three training cases, outperforming CondNet, which was trained on an adequate number of cases. The conductivity maps generated by the proposed method yielded better results in brain electrical field simulations than CondNet.<i>Significance</i>. These findings demonstrate the high utility of the proposed method in brain electrical field simulations and suggest its potential applicability to other medical image analysis tasks and simulations.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Monte Carlo method for the quantitative analysis of triage algorithms in mass casualty events.","authors":"Tobias Schwerdtfeger, Lorenzo Brualla","doi":"10.1088/1361-6560/adcbfc","DOIUrl":"https://doi.org/10.1088/1361-6560/adcbfc","url":null,"abstract":"<p><p><i>Objective.</i>In mass casualty scenarios, efficient triage algorithms are used to prioritize medical care when resources are outnumbered by victims. This research proposes a computational approach to quantitatively analyze and optimize triage algorithms by developing a Monte Carlo code which is subsequently validated against the few quantitative data.<i>Approach</i>. The developed Monte Carlo code is used to simulate several mass casualty events, namely car accidents, burns, shootings, sinking ships and a human stampede. Four triage algorithms- modified simple triage and rapid treatment, primäres Ranking zur initialen Orientierung im Rettungsdienst, CareFlight, and field triage score (FTS)-are evaluated using metrics like mortality, overtriage, undertriage, sensitivity, and specificity.<i>Main results.</i>Results indicate that, on average, the analyzed algorithms achieve about 35% accuracy in classifying critical casualties when compared to a perfect algorithm, with FTS being the less accurate. However, when all casualties are considered, algorithm performance improves to around 63% of a perfect algorithm, except for FTS. The study identifies an increased probability of false positives for red categorization due to comorbidities and a higher tendency for false negatives in casualties with burns or internal trunk injuries.<i>Significance.</i>Despite variations in vital sign measurements, triage classification results do not depend on the measurement uncertainties of the paramedics. The ethically challenging decision, of withholding medical care from low-survival probability victims, leads to a 63% reduction in mortality among critical casualties. This research establishes a quantitative method for triage algorithm studies, highlighting their robustness to measurement uncertainties.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":"70 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}