Physica Medica-European Journal of Medical Physics最新文献

{"title":"Radiation exposure risk for various personnel in the catheterization laboratory: A systematic review and meta-analysis","authors":"Brúnó B Balázs ,&nbsp;David Laczkó ,&nbsp;Dorottya Gergő ,&nbsp;Bence Szabó ,&nbsp;Gábor Duray ,&nbsp;Zsolt Molnár ,&nbsp;Dénes B Horváthy ,&nbsp;Judit Papp ,&nbsp;Péter Hegyi ,&nbsp;Béla Merkely ,&nbsp;István F Édes","doi":"10.1016/j.ejmp.2025.105096","DOIUrl":"10.1016/j.ejmp.2025.105096","url":null,"abstract":"<div><h3>Purpose</h3><div>Radiation exposure is a well-recognized occupational hazard for catheterization lab personnel. However, the extent of exposure disparities among different staff roles remains unclear. Existing research primarily focuses on primary operators, leaving a gap in understanding radiation risks for ancillary staff. This study aims to evaluate how staff positioning and shielding affect radiation exposure, focusing on disparities between primary operators and ancillary staff during fluoroscopy-guided cardiovascular procedures.</div></div><div><h3>Method</h3><div>After a systematic search across five databases on November 20, 2023, we included studies reporting radiation data for coronary angiographies, structural heart interventions, electrophysiological procedures, or endovascular aorta interventions, with at least one ancillary staff member in prespecified positions. Radiation exposures were compared relative to the primary operator using the Ratio of Means (ROM) during <em>meta</em>-analysis. Risk of Bias was assessed using RoB-2 or ROBINS-E. The review protocol was registered as CRD42023484491.</div></div><div><h3>Results</h3><div>Our <em>meta</em>-analysis, based on 8116 measurements from 3091 procedures across 23 studies, suggests that personnel at the patient’s head without shielding may experience higher radiation exposure than primary operators (ROM 1.77, 95% CI: 0.75–4.18), although this difference didn’t reach statistical significance. Shielded workers at the head or in secondary/assistant positions received significantly lower radiation than primary operators (ROM 0.26, 95% CI: 0.12–0.57; ROM 0.33, 95% CI: 0.25–0.43).</div></div><div><h3>Conclusions</h3><div>Our results suggest a potential disparity in radiation exposure among catheterization laboratory personnel, with unshielded workers at the patient’s head tending to receive the highest levels of exposure.</div><div>Dedicated shielding solutions and attention to all personnel are imperative.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105096"},"PeriodicalIF":2.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902727","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":"Development of a GEANT4-Based Monte Carlo algorithm for polarized nuclear imaging simulations integrated into GATE","authors":"Rasool Safari ,&nbsp;Yasaman Aboulghasemi ,&nbsp;Reza Faghihi ,&nbsp;Mohammadreza Parishan ,&nbsp;Zahra Rakeb","doi":"10.1016/j.ejmp.2025.105081","DOIUrl":"10.1016/j.ejmp.2025.105081","url":null,"abstract":"<div><h3>Background</h3><div>Polarized Nuclear Imaging (PNI) is a novel gamma imaging approach that encodes spatial information by using polarized radioactive nuclei and manipulating them with magnetic fields, gradients, and RF pulses. The resulting anisotropic photon emission yields direct k-space encoding, removing the need for collimators.</div></div><div><h3>Purpose</h3><div>The work will focus on developing the first, high-performance Monte Carlo-based algorithm for PNI, fully integrated into the GATE framework. Using Monte Carlo simulations, there is an expectation of a strong push in research concerning PNI and a better understanding and use of this new imaging technique.</div></div><div><h3>Methods</h3><div>An algorithm based on Geant4 was implemented and coupled with GATE in the form of a new type of source. This extension allows users to define a PNI source, configure its parameters, and use GATE’s basic functionalities to perform simulation studies in PNI. The source of GATE-based PNI generates photons in directions according to the PNI-encoded method, which maps spatial information into the spin orientations of polarized radioactive nuclei.</div></div><div><h3>Results</h3><div>The tool exhibited extremely small average relative errors (∼0.0000018 %) when replicating theoretical angular distributions of gamma emissions from oriented nuclei, and a 3.57 % difference from theory in extracting k-space data using the detector-based PNI method. A complex PNI source also yielded results consistent with experimental data.</div></div><div><h3>Conclusions</h3><div>This GATE-based PNI simulation toolkit offers an efficient, user-friendly, and accurate method for investigating PNI, paving the way for advanced research and system optimization.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105081"},"PeriodicalIF":2.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902728","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":"In silico evaluation of the potential of very high energy electrons delivered in both conventional and FLASH regimes for the SBRT treatment of pancreatic cancer: A report of three case studies","authors":"A. De Gregorio ,&nbsp;A. Muscato ,&nbsp;A. Burattini ,&nbsp;D. Carlotti ,&nbsp;M. Fiore ,&nbsp;G. Franciosini ,&nbsp;T. Insero ,&nbsp;M. Marafini ,&nbsp;V. Marè ,&nbsp;V. Patera ,&nbsp;F. Quattrini ,&nbsp;S. Ramella ,&nbsp;A. Schiavi ,&nbsp;M. Toppi ,&nbsp;G. Traini ,&nbsp;A. Trigilio ,&nbsp;A. Sarti","doi":"10.1016/j.ejmp.2025.105076","DOIUrl":"10.1016/j.ejmp.2025.105076","url":null,"abstract":"<div><h3>Background and purpose:</h3><div>As the incidence and mortality rates of pancreatic cancer continue to rise, the search for effective treatments is becoming increasingly urgent. Among the therapeutic approaches, highly hypofractionated stereotactic treatments are being explored. This paper explores the potential of Very High Energy Electrons (VHEE) in the range of 80-130 MeV, in light of recent advances in compact accelerator technology and its compatibility with ultra-high dose rate (UHDR) delivery.</div></div><div><h3>Materials and methods:</h3><div>Using dose-volume histograms and dose maps, we compared VHEE treatment plans simulated and optimized assuming both conventional and UHDR delivery scenarios against state-of-the-art volumetric modulated arc therapy (VMAT) treatment plans that were used to treat three patients. Dose maps have been obtained assuming an IMRT-like geometry. The implemented VHEE beam model assumes a C-band compact accelerating technology. Results show that electrons below 130 MeV have a clear potential for the effective treatment of pancreatic cancer, even if delivered in conventional conditions. UHDR delivery has been explored evaluating the gain that the FLASH effect could provide in terms of dose escalation to the PTV while constraining the maximum allowed biological dose to the duodenum.</div></div><div><h3>Conclusion:</h3><div>The obtained results demonstrate the suitability of VHEE for pancreatic cancer treatment with optimized plans that are clinically acceptable even without considering the additional sparing from the FLASH effect. Their suitability for being delivered at FLASH rates makes them an excellent candidate for the future of external beam radiotherapy.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105076"},"PeriodicalIF":2.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902726","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":"Estimation of secondary cancer risks following rectal cancer photon and proton therapy: A computational phantom study","authors":"Nipon Saiwong ,&nbsp;Sasikarn Chamchod ,&nbsp;Pattarakan Suwanbut ,&nbsp;Sawanee Suntiwong ,&nbsp;Thiansin Liamsuwan","doi":"10.1016/j.ejmp.2025.105083","DOIUrl":"10.1016/j.ejmp.2025.105083","url":null,"abstract":"<div><h3>Purpose</h3><div>The aim of this work was to assess secondary cancer risks after rectal cancer intensity modulated radiation therapy (IMRT) and intensity modulated proton therapy (IMPT) using a computational phantom.</div></div><div><h3>Method</h3><div>A computational male phantom was used to represent Thai rectal cancer patients. Ethos treatment planning system (TPS) was used to calculate the IMRT plan with 12 fields of 6 MV flattening filter free (FFF) photon beams, while matRad was employed to calculate IMPT plans with 2 (lateral and oblique), 3 and 5 fields. The IMPT plans were recalculated by Tool for Particle Simulation (TOPAS) Monte Carlo simulation to account for secondary radiations. The assessment of secondary cancer risks in terms of organ equivalent dose (OED) and lifetime attributable risk (LAR) was conducted using the mechanistic model.</div></div><div><h3>Results</h3><div>The IMPT plans yielded lower radiation doses to the organs at risk (OARs) than the IMRT plan. The organ-specific LARs for the IMRT plan were 2.247 % for the colon, 0.098 % for the bowel and 0.038 % for the bladder, while the LARs for the IMPT plans ranged from 1.475 % to 1.537 % for the colon, 0.014 % to 0.016 % for the bowel, and 0.071 % to 0.092 % for the bladder. The colon was found to have the highest risk of developing secondary cancer. The risks of developing secondary bone and soft tissue sarcomas as well as secondary cancer in out-of-field organs were negligibly low except in the IMRT case.</div></div><div><h3>Conclusion</h3><div>Among the investigated IMRT and IMPT plans, the 2-field oblique IMPT plan yielded the lowest risk.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105083"},"PeriodicalIF":2.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893534","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":"Evaluation of the dosimetric accuracy of HyperSight CBCT for CBCT-only adaptive radiotherapy workflow","authors":"Francesca Dusi,&nbsp;Fabio Busato,&nbsp;Alessandro Testolin,&nbsp;Davide Fiorentin,&nbsp;Francesca Tessari,&nbsp;Mattia Nicoletto,&nbsp;Marco Fusella","doi":"10.1016/j.ejmp.2025.105091","DOIUrl":"10.1016/j.ejmp.2025.105091","url":null,"abstract":"<div><h3>Background/introduction</h3><div>This study evaluates the dosimetric performance of HyperSight CBCT (HS-CBCT) images for CBCT-only adaptive radiotherapy workflows.</div></div><div><h3>Methods</h3><div>We evaluated Hounsfield unit (HU) accuracy and dose calculation performance using both Feldkamp-Davis-Kress (FDK) and Acuros reconstructions in phantom and clinical datasets (brain, breast, pelvis). HU deviations were reported relative to planning CT. Longitudinal HU stability was assessed over 20 CBCT sessions in a prostate cohort. Gamma passing rates (2 %/2mm) were used for dosimetric evaluation.</div></div><div><h3>Results</h3><div>Acuros-reconstructed CBCT images demonstrated HU agreement within 28 HU of the planning CT, compared to deviations up to 284 HU for FDK (the relative coefficient of variation −CV- of the difference from the pCT reference value were 2 % and 20 % for Acuros and FDK respectively). Dose recalculations on Acuros images resulted in higher gamma passing rates, particularly in pelvic cases (97.8 % vs 96.6 % with FDK, p &lt; 0.05). HU stability analysis over 20 CBCT sessions in prostate patients confirmed reproducibility, with standard deviations of 5.0 HU for bone and 4.2 HU for bladder.</div></div><div><h3>Conclusion</h3><div>This study provides the first comprehensive, multi-site and longitudinal clinical validation of HyperSight CBCT with Acuros reconstruction for ART workflows. Our results demonstrate high HU fidelity and robust dose calculation performance, supporting the clinical feasibility of CBCT-only workflows across different anatomical regions and throughout the course of treatment.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105091"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891836","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":"Performance of multi-vendor auto-segmentation models for thoracic organs at risk trained on a single dataset","authors":"Sevgi Emin ,&nbsp;Elia Rossi ,&nbsp;Mattias Hedman ,&nbsp;Marcela Giovenco ,&nbsp;Fernanda Villegas ,&nbsp;Eva Onjukka","doi":"10.1016/j.ejmp.2025.105089","DOIUrl":"10.1016/j.ejmp.2025.105089","url":null,"abstract":"<div><h3>Introduction</h3><div>This study evaluates the delineation quality of artificial intelligence (AI)-based models for auto-segmentation trained on the same dataset, as the intrinsic performance cannot be evaluated for commercial solutions due to differences in training datasets. A diverse set of challenging thoracic organs-at-risk (OAR) were chosen, to reveal potential limitations of AI-based tools which are relevant for their clinical adoption.</div></div><div><h3>Materials &amp; Methods</h3><div>A structure set with 16 OAR was delineated and reviewed by radiation oncology experts for 250 patients with lung tumours (200/50 for training/testing). Three participating vendors had access to the training dataset for a limited time to develop a model mimicking their commercial model development strategies.</div><div>The models were tested on the blind test dataset by the authors. A quantitative analysis was performed employing Dice Similarity Coefficient (DSC), surface DSC (sDSC), the 95-th percentile of the Hausdorff Distance (HD95) and average symmetric surface distance (ASSD). Inter-observer variability in manual segmentation was estimated by three independent expert delineations for a subset of five test patients.</div></div><div><h3>Results</h3><div>13 OAR had DSC &gt; 0.8, 9 had sDSC &gt; 0.8, 10 had ASSD &lt; 0.5 mm and 5 had HD95 &lt; 1 mm. The most challenging structures to auto-segment were the brachial plexus, pulmonary vein, and vena cava inferior. The overall results for all models were exceeding the inter-observer variability for all metrics.</div></div><div><h3>Conclusion</h3><div>While the evaluated AI-models perform very well for some OAR, they appear less successful at modelling organs with branching structures and poor image contrast, even when trained on a large homogeneous dataset.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105089"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890190","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":"Development of a context-aware integrated training module based on large language models for continuous education in radiation protection","authors":"Anna Romanyukha,&nbsp;Mahta Mazloumi,&nbsp;Thomas De Waelheyns,&nbsp;Nidhi Mishra,&nbsp;Jurgen Jacobs,&nbsp;Niki Fitousi","doi":"10.1016/j.ejmp.2025.105090","DOIUrl":"10.1016/j.ejmp.2025.105090","url":null,"abstract":"<div><h3>Purpose</h3><div>Reliability of LLM-based AI chatbots can be enhanced by using domain-specific models with a controlled knowledge base, especially relevant in the context of education and training of healthcare professionals and researchers. The aim was to produce an LLM data model with the goal of continuous education in radiation protection, that allows users to access reliable scientific information by querying it on specific topics, eliminating the need for manually perusing educational materials.</div></div><div><h3>Method</h3><div>A domain-specific LLM data model was developed and trained using custom knowledge from several domains, tested applying various test scenarios, and fine-tuned to ensure optimal selections of hyperparameters including top k, chunk size, temperature, max tokens etc.</div></div><div><h3>Results</h3><div>The final model produced reliable and accurate answers to a variety of users and queries based on controlled educational materials. Embedding model and similarity cutoff had the greatest impact on model performance.</div></div><div><h3>Conclusion</h3><div>The developed model was trained and validated on radiation protection training material, allowing users to access information on topics including radiobiology and radiation protection in a quick and reliable manner.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105090"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890192","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":"Phantom-based assessment of focused ultrasound thermal effects with conventional magnetic resonance imaging","authors":"Anastasia Antoniou ,&nbsp;Nikolas Evripidou ,&nbsp;Antria Filippou ,&nbsp;Leonidas Georgiou ,&nbsp;Antreas Chrysanthou ,&nbsp;Antonis Christofi ,&nbsp;Yiannis Roussakis ,&nbsp;Cleanthis Ioannides ,&nbsp;Yuhan Lyu ,&nbsp;Jufeng Zhao ,&nbsp;Liyang Yu ,&nbsp;Wenjun Li ,&nbsp;Christakis Damianou","doi":"10.1016/j.ejmp.2025.105078","DOIUrl":"10.1016/j.ejmp.2025.105078","url":null,"abstract":"<div><h3>Background and objective</h3><div>This study presents key findings from Magnetic Resonance Imaging (MRI)-guided Focused Ultrasound (FUS) sonication experiments in a specialized gel phantom, aimed at demonstrating the effectiveness of using conventional T1-Weighted (T1-W) and T2-Weighted (T2-W) Turbo Spin Echo (TSE) sequences to assess FUS thermal effects and related system performance.</div></div><div><h3>Methods</h3><div>Three custom-manufactured, single-element spherically focused ultrasonic transducers were utilized in this study. The temporal regression of lesions induced by high-power FUS in the phantom model was investigated within a 3T MRI scanner for both employed sequences. Thermal effects within the phantom were characterized through visual assessment and quantitative measurements of lesion size and contrast-to-noise ratio (CNR) on TSE images, under different focal intensities, exposure durations, and focal depths, complemented by MR thermometry data.</div></div><div><h3>Results</h3><div>The phantom exhibited hyperintense lesions with excellent contrast on T2-W TSE imaging, chosen for its superior contrast and faster lesion resolution. Lesion size increased with intensity and exposure time, though trends varied by transducer. Cigar-shaped or non-uniform elongated lesions developed, reflecting sharp or poor transducer focusing, with signal intensity decreasing as focal depth increased. A strong correlation between lesion CNR and accumulated thermal dose was observed, emphasizing that changes in imaging contrast can consistently reflect thermal effects.</div></div><div><h3>Conclusion</h3><div>The proposed phantom-based MRI approach shows promise as a tool for routine assessment of FUS ablation system performance by monitoring lesion dynamics using conventional T2-W TSE imaging, thereby streamlining the quality assurance workflow.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105078"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890193","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":"Spectral computed tomography thermometry for thermal ablation: applicability and needle artifact reduction","authors":"Lennart R. Koetzier ,&nbsp;Pim Hendriks ,&nbsp;Jan W.T. Heemskerk ,&nbsp;Niels R. van der Werf ,&nbsp;Mark Selles ,&nbsp;Aart J. van der Molen ,&nbsp;Maarten L.J. Smits ,&nbsp;Marlies C. Goorden ,&nbsp;Mark C. Burgmans","doi":"10.1016/j.ejmp.2025.105093","DOIUrl":"10.1016/j.ejmp.2025.105093","url":null,"abstract":"<div><h3>Background</h3><div>Effective thermal ablation of liver tumors requires precise monitoring of the ablation zone. Computed tomography (CT) thermometry can non-invasively monitor lethal temperatures but suffers from metal artifacts caused by ablation equipment.</div></div><div><h3>Purpose</h3><div>This study assesses spectral CT thermometry’s applicability during microwave ablation, comparing the reproducibility, precision, and accuracy of attenuation-based versus physical density-based thermometry. Furthermore, it identifies optimal metal artifact reduction (MAR) methods: O-MAR, deep learning-MAR, spectral CT, and combinations thereof.</div></div><div><h3>Methods</h3><div>Four gel phantoms embedded with temperature sensors underwent a 10- minute, 60 W microwave ablation imaged by dual-layer spectral CT scanner in 23 scans over time. For each scan attenuation-based and physical density-based temperature maps were reconstructed. Attenuation-based and physical density-based thermometry models were tested for reproducibility over three repetitions; a fourth repetition focused on accuracy. MAR techniques were applied to one repetition to evaluate temperature precision in artifact-corrupted slices.</div></div><div><h3>Results</h3><div>The correlation between CT value and temperature was highly linear with an R-squared value exceeding 96 %. Model parameters for attenuation-based and physical density-based thermometry were −0.38 HU/°C and 0.00039 °C⁻¹, with coefficients of variation of 2.3 % and 6.7 %, respectively. Physical density maps improved temperature precision in presence of needle artifacts by 73 % compared to attenuation images. O-MAR improved temperature precision with 49 % compared to no MAR. Attenuation-based thermometry yielded narrower Bland-Altman limits-of-agreement (−7.7 °C to 5.3 °C) than physical density-based thermometry.</div></div><div><h3>Conclusions</h3><div>Spectral physical density-based CT thermometry at 150 keV, utilized alongside O-MAR, enhances temperature precision in presence of metal artifacts and achieves reproducible temperature measurements with high accuracy.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105093"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890191","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 methodological approach for the comparison of CT systems in terms of radiation dose and image quality","authors":"Evgenia Konstantinou ,&nbsp;Antonios Ε. Papadakis ,&nbsp;Maria Daskalogiannaki ,&nbsp;Apostolos Karantanas ,&nbsp;John Damilakis","doi":"10.1016/j.ejmp.2025.105092","DOIUrl":"10.1016/j.ejmp.2025.105092","url":null,"abstract":"<div><h3>Purpose</h3><div>This study aims to apply a comparative methodology for two different computed tomography (CT) scanners, by evaluating patient radiation dose and image quality.</div></div><div><h3>Materials &amp; methods</h3><div>A total of 189 consecutive non-enhanced and enhanced abdominal examinations, were performed using General Electric Revolution GSI (scanner A) and Siemens Somatom Drive (scanner B) scanners. Both protocols had been previously optimized by the same team for the two scanners, ensuring consistent image quality during comparison. CT dose index volume (CTDI_vol) and dose-length product (DLP) were recorded, and percent dose difference between scanners was estimated. Image quality was objectively assessed using image noise and contrast-to-noise ratio (CNR), and subjectively with a five-point scale. Utilizing the same protocols, an anthropomorphic phantom was irradiated to estimate organ doses. Statistical analysis was conducted to compare the examined parameters.</div></div><div><h3>Results</h3><div>The CTDI_vol and DLP for two scanners were 16.4–21.8 mGy and 494.7–1030.3 mGy*cm, respectively. Doses for scanner B were up to 41 % lower than scanner A. No significant CTDI_vol and DLP differences were found for unenhanced scans. Organ doses ranged from 5.0 to 16.9 mGy for both scanners, with scanner B delivering lower doses. Image quality was comparable between two CT systems. No statistical differences were found for image quality parameters, except for CNR in non-enhanced examinations. Radiologists’ ratings were consistent with the objective assessment.</div></div><div><h3>Conclusion</h3><div>A methodology was applied to compare two different CT scanners, regardless of patient selection criteria. Scanner B achieved lower doses for contrast-enhanced exams than scanner A.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105092"},"PeriodicalIF":2.7,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887190","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}