Physica Medica-European Journal of Medical Physics最新文献

{"title":"Bragg peak position monitoring using silicon and titanium nanoparticles as prompt-gamma tracers","authors":"Bartosz Klębowski ,&nbsp;Barbara Kołodziej ,&nbsp;Barbara Beus ,&nbsp;Magdalena Garbacz ,&nbsp;Ronja Hetzel ,&nbsp;Jonas Kasper ,&nbsp;Aleksandra Kaszlikowska ,&nbsp;Andrzej Magiera ,&nbsp;Aleksandra Wrońska","doi":"10.1016/j.ejmp.2025.105068","DOIUrl":"10.1016/j.ejmp.2025.105068","url":null,"abstract":"<div><h3>Purpose</h3><div>Spherical silicon and rods-like titanium oxide nanoparticles (NPs) have been analyzed for use in the proton range verification method in proton therapy (main goal), as well as radiosensitizers (second goal) in this therapy due to their physical and biological properties. The method involved the use of tracers emitting prompt-gamma radiation during irradiation with protons. The basic assumption of the method is to selectively deliver the tracer in form of NPs to the tumor. The cytotoxicity of the obtained nanomaterials was also checked against normal and cancer cells.</div></div><div><h3>Methods and Materials</h3><div>Correlation between the Bragg peak (BP) position in the PMMA phantom and the signal emitted by the analyzed tracers were determined on the basis of simulations carried out using the Geant4 toolkit. To determine the cytotoxicity of nanosilicone and nanotitanium, as well as their radiosensitizing properties a classic MTS test and a modified multiple MTS test were performed. The location of both types of NPs was determined using holotomographic microscopy.</div></div><div><h3>Results</h3><div>For silicon NPs, a signal was observed when the BP was located entirely in the structure imitating a tumor and decreased when the BP was entirely outside the structure. In the case of titanium NPs, the signal did not correlate with the position of the structure mimicking a tumor. Both types of NPs at low concentrations turned out to be non-toxic to both cell lines. It has been shown that both types of nanoparticles have promising radiosensitizing properties, in particular towards cancer cells.</div></div><div><h3>Conclusions</h3><div>When it comes to physical properties, silicon appears to be an optimal candidate for use in proton therapy monitoring. Moreover, the silica NPs turned out to be slightly more effective radiosensitizers than titanium NPs.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105068"},"PeriodicalIF":2.7,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810195","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":"Weakly supervised commissioning of externally developed auto-segmentation models and applied to male pelvis MR auto-segmentation","authors":"Bastiaan W.K. Schipaanboord ,&nbsp;Peter J. Koopmans ,&nbsp;Erik van der Bijl ,&nbsp;Charlotte L. Brouwer ,&nbsp;Tomas Janssen","doi":"10.1016/j.ejmp.2025.105057","DOIUrl":"10.1016/j.ejmp.2025.105057","url":null,"abstract":"<div><h3>Introduction:</h3><div>When introducing an auto-segmentation model into clinical practice, assessing the quality of the predicted segmentations and the robustness of the model over a wide range of anatomical variation and/or image quality is difficult. Especially, when the model is provided by an external party and the institution introducing the model does not possess a high-quality dataset to commission the model on.</div></div><div><h3>Materials &amp; Methods:</h3><div>Assuming that a model is more likely to fail for an atypical case as opposed to a more average one, we propose a methodology that selects cases for commissioning using unsupervised anomaly detection. For this, the model supplier provides a set of image/shape features that correlate with model performance on the training data. Next, the receiving hospital can use these features to train an unsupervised anomaly detector on a large dataset of unlabeled cases and use the anomaly scores to select representative cases for commissioning of the model. Since the anomaly detector is trained on unlabeled data, a large, high-quality, curated dataset is not required on the receiving hospital side.</div></div><div><h3>Results:</h3><div>Using the proposed approach, the likelihood of selecting atypical edge cases with low segmentation performance was increased, as compared to random selection. For a selection of 20 cases, an increase of 22% was observed.</div></div><div><h3>Conclusions:</h3><div>The increased performance spread provides a more representative range of expected performance in clinical practice. This approach could be used for model commissioning to increase the confidence that the model performs well over a wide range of expected anatomical variation.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105057"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144769415","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":"Validating an explainable radiomics approach in non-small cell lung cancer combining high energy physics with clinical and biological analyses","authors":"Mariagrazia Monteleone ,&nbsp;Francesca Camagni ,&nbsp;Stefano Percio ,&nbsp;Letizia Morelli ,&nbsp;Guido Baroni ,&nbsp;Simone Gennai ,&nbsp;Pietro Govoni ,&nbsp;Chiara Paganelli","doi":"10.1016/j.ejmp.2025.105054","DOIUrl":"10.1016/j.ejmp.2025.105054","url":null,"abstract":"<div><h3>Purpose</h3><div>This study aims at establishing a validation framework for an explainable radiomics-based model, specifically targeting classification of histopathological subtypes in non-small cell lung cancer (NSCLC) patients.</div></div><div><h3>Methods</h3><div>We developed an explainable radiomics pipeline using open-access CT images from the cancer imaging archive (TCIA). Our approach incorporates three key prongs: SHAP-based feature selection for explainability within the radiomics pipeline, a technical validation of the explainable technique using high energy physics (HEP) data, and a biological validation using RNA-sequencing data and clinical observations.</div></div><div><h3>Results</h3><div>Our radiomic model achieved an accuracy of 0.84 in the classification of the histological subtype. The technical validation performed on the HEP domain over 150 numerically equivalent datasets, maintaining consistent sample size and class imbalance, confirmed the reliability of SHAP-based input features. Biological analysis found significant correlations between gene expression and CT-based radiomic features. In particular, gene <em>MUC21</em> achieved the highest correlation with the radiomic feature describing the10th percentile of voxel intensities (r = 0.46, p &lt; 0.05).</div></div><div><h3>Conclusion</h3><div>This study presents a validation framework for explainable CT-based radiomics in lung cancer, combining HEP-driven technical validation with biological validation to enhance interpretability, reliability, and clinical relevance of XAI models.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105054"},"PeriodicalIF":2.7,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724454","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":"Calibration services for X-ray multimeters in Europe: current situation and future needs","authors":"Ivana Komatina ,&nbsp;Vedrana Makarić ,&nbsp;Miloš Živanović ,&nbsp;Paula Toroi ,&nbsp;Aino Tietäväinen ,&nbsp;Massimo Pinto ,&nbsp;Luigi Rinaldi ,&nbsp;Markus Borowski ,&nbsp;Siarhei Saroka ,&nbsp;Nikola Kržanović ,&nbsp;Alessia Ciccotelli ,&nbsp;Bartel Jansen ,&nbsp;Stefan Pojtinger ,&nbsp;Ana Fernandes ,&nbsp;Vittorio Cannatà ,&nbsp;Mika Kortesniemi","doi":"10.1016/j.ejmp.2025.105055","DOIUrl":"10.1016/j.ejmp.2025.105055","url":null,"abstract":"<div><h3>Introduction</h3><div>Optimization and quality control of the diagnostic and interventional radiology procedures is usually performed with an X-ray multimeter (XMM) based on the non-invasive measurements of different X-ray tube and output parameters obtained from the X-ray beam, such as air kerma, tube voltage and half-value layer. Standardization and metrological support need to be improved, and harmonized calibration procedures are not available for all quantities. There is also a lack of data on performance of XMMs in different measurement conditions relevant for clinical practice.</div></div><div><h3>Methods</h3><div>The needs for calibration of XMMs and current state of the art of calibration services were investigated by performing an overview of the standards, conducting surveys addressed to the clinical medical physicists and calibration laboratories and investigating the key comparison database.</div></div><div><h3>Results</h3><div>There are widely available calibration services for air kerma measurements for a large range of radiation qualities. However, there is a lack of calibration services for all other measured quantities, and very few laboratories besides the manufacturers are able to perform these calibrations. In addition, standardization gaps with non-harmonized calibration and measurement procedures for these quantities were found.</div></div><div><h3>Conclusion</h3><div>New calibration services with harmonized procedures are needed for XMMs, especially for quantities beyond air kerma. There is a need to better understand and reduce measurement uncertainty for some quantities. New procedures will be developed within the TraMeXI project and disseminated to the standardization bodies, metrology and medical physics community.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105055"},"PeriodicalIF":2.7,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723463","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":"Physics-informed machine learning for predicting MLC and gantry errors in VMAT: a feature engineering approach","authors":"Perumal Murugan,&nbsp;Ravikumar Manickam","doi":"10.1016/j.ejmp.2025.105064","DOIUrl":"10.1016/j.ejmp.2025.105064","url":null,"abstract":"<div><h3>Background</h3><div>This study presents a physics-informed, feature-engineered machine learning (ML) framework to predict multileaf collimator (MLC) and gantry positional errors in volumetric modulated arc therapy (VMAT)</div></div><div><h3>Methods</h3><div>Data from 32 VMAT trajectory logs (TrueBeam linac, HD120 MLC) were synchronized with DICOMRT plans to extract delivery dynamics. Novel physics-based parameters were introduced: a friction factor, an enhanced gravity vector, and MLC speed-normalized features. Three ML models XGBoost, LightGBM, and deep neural networks (DNNs) were optimized using Optuna and trained on trajectory log and DICOM-RT-derived datasets. Feature importance was evaluated via Spearman correlation, mutual information, and SHapley Additive Explanations (SHAP).</div></div><div><h3>Results</h3><div>Systematic discrepancies between DICOM-RT and trajectory log data were identified, with mean absolute deviations of 7.0 % (MLC speed), 8.0 % (gantry speed), and 8.5 % (dose rate). MLC speed emerged as the dominant predictor (Spearman: r_s = 0.891), while friction and gravity features exhibited significant correlations (r_s = 0.46 and 0.33, respectively). Mutual information revealed non-monotonic dependencies between gantry error and gantry angle (score: 0.34). LightGBM and XGBoost achieved superior MLC error prediction (MAE: 0.0019 mm, RMSE: 0.0027 mm), capturing &gt; 90 % of observed errors, while DNNs lagged by 30 %. Engineered features reduced residual errors by 30 %. Gantry error predictions showed lower accuracy (MAE: 0.012°–0.015°). SHAP analysis highlighted physics-driven features as top contributors.</div></div><div><h3>Conclusion</h3><div>This work underscores the critical role of domain knowledge in ML for radiotherapy, achieving a 30% error reduction through physics-based feature engineering. The findings advocate for prioritizing feature space exploration alongside model optimization to enhance VMAT quality assurance.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105064"},"PeriodicalIF":2.7,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724682","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":"Assessment of physical phantoms produced in the PHENOMENO project utilizing three fused filament fabrication approaches","authors":"Kristina Bliznakova ,&nbsp;Nikolay Dukov ,&nbsp;Zhivko Bliznakov ,&nbsp;Viktoria Petkova ,&nbsp;Vencislav Nastev ,&nbsp;Vasilis Eleftheriadis ,&nbsp;Panagiotis Papadimitroulas ,&nbsp;Nikiforos Okkalidis ,&nbsp;Elena Ivanova ,&nbsp;Tsvetelina Teneva ,&nbsp;Georgi Todorov ,&nbsp;Giovanni Mettivier ,&nbsp;Paolo Russo","doi":"10.1016/j.ejmp.2025.105061","DOIUrl":"10.1016/j.ejmp.2025.105061","url":null,"abstract":"<div><h3>Introduction</h3><div>The aim of this study was to evaluate the suitability of three approaches in producing physical breast phantoms using the low-cost 3D printing fused filament fabrication (FFF) technique.</div></div><div><h3>Methods</h3><div>Three physical phantoms were produced: the first (PB1) is based on PLA filament extruded with different extrusion rates and constant printing speed; the second (PB2) and third (PB3) were each printed with two filaments: ABS-ASA for PB2 and HIPS-ASA for PB3. The phantoms were scanned using a clinical CT facility at different kilovoltage (kV) settings. Objective analysis comprised power spectrum, fractal dimensions, histogram metrics (skewness, kurtosis), and Hounsfield Unit (HU) values. Experienced radiologists performed a subjective assessment.</div></div><div><h3>Results</h3><div>All phantoms demonstrated β indexes in the range of 1.39–2.72, with PB2 showing the lowest values. The measured HU values for the breast tissues as a whole increased with increasing kV. PB1 showed very good results in terms of measured HU values for glandular tissue, skin, and adipose tissue. In PB2, ABS proved to be well suited for representing adipose tissue, whereas HIPS exhibited lower than expected HU values. Similarly, in PB3, ASA showed HU values that were lower than those reported in the literature. These discrepancies highlight the need for further optimization of printing parameters for HIPS and ASA materials. Subjective evaluation revealed no significant differences in the visual quality of the phantoms.</div></div><div><h3>Conclusions</h3><div>FFF printing challenges hinder widespread anthropomorphic phantom production. Further research is needed for dual-material printing.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105061"},"PeriodicalIF":3.3,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703598","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":"Decommissioning procedure and induced activation levels in the vault walls of a 11 MeV self-shielded Medical Cyclotron: simulations and measurements","authors":"Simone Manenti ,&nbsp;Carlo Bergamaschi ,&nbsp;Francesco Broggi ,&nbsp;Andrea Ferrari ,&nbsp;Flavia Groppi ,&nbsp;Alessandro Loria ,&nbsp;Massimiliano Nizzi ,&nbsp;Antonella del Vecchio ,&nbsp;Riccardo Calandrino","doi":"10.1016/j.ejmp.2025.105060","DOIUrl":"10.1016/j.ejmp.2025.105060","url":null,"abstract":"<div><div>This study outlines the decommissioning process of an 11 MeV self-shielded medical cyclotron operated for over 12 years at the Ospedale San Raffaele, Milano, Italy. A comprehensive analysis of neutron-induced activation in the vault walls was performed to guide safe demolition procedures. Using FLUKA Monte Carlo simulations and laboratory-based gamma and beta spectrometry, the activity of long-lived radionuclides, particularly ⁵⁵Fe, was evaluated across multiple wall depths. Results demonstrated that residual activity was primarily confined to the top 5 cm of the wall, with some samples exceeding the Italian clearance level of 1 Bq g⁻¹ for ⁵⁵Fe. Occupational exposure to demolition staff was assessed via external dosimeters and internal contamination checks, with all values reported below regulatory limits. These findings confirm that while personnel are not at radiological risk, certain components and wall materials must be classified as low-level radioactive waste (LLRW) and require long-term storage.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105060"},"PeriodicalIF":3.3,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695207","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":"Design and manufacture of a radioactive 3D printed phantom for PET quality control","authors":"Jennifer Robinson,&nbsp;Dominic Rushforth,&nbsp;Iain Murray,&nbsp;Glenn Flux,&nbsp;Jonathan Gear","doi":"10.1016/j.ejmp.2025.105058","DOIUrl":"10.1016/j.ejmp.2025.105058","url":null,"abstract":"<div><h3>Aim/Introduction</h3><div>It is proposed to incorporate radioisotopes into the resin material of 3D-printers to facilitate the production of complex phantoms for PET quality control. This project aimed to demonstrate this possibility by producing a lesion detection phantom with associated software for PET image evaluation and optimisation.</div></div><div><h3>Methods</h3><div>80 MBq of ⁸⁹Zr were added to the support resin of an Objet30-Pro 3D-printer and printed alongside the build resin to create a bespoke phantom with a heterogeneous activity distribution. The phantom contained 40 radioactive cylinders ranging from 1.3 to 13.9 mm in diameter. The lesion to background activity concentration varied down the length of the phantom at ratios of 3:2, 2:1, 4:1, 8:1 and 1:0. Imaging was performed using a list mode acquisition on a Siemens Biograph-mCT PET/CT scanner. Reconstructions were performed using a subset of the data, representing acquisition durations ranging from 5 s to 1 h, with and without point spread function (PSF) modelling. Receiver operator characteristic analysis was conducted and the area under the curve calculated to quantify image quality.</div></div><div><h3>Results</h3><div>The phantom took 96 h to manufacture and was produced with suitable print quality, matching the original design specification. Differences in image quality, due to acquisition duration, image contrast and PSF modelling were quantified. The testing approach was also shown to be repeatable in a test–retest scenario, demonstrating the usefulness of such phantoms for image evaluation and quality control.</div></div><div><h3>Conclusion</h3><div>Radioactive 3D printing is a promising tool and could be utilised for the manufacture of PET QC phantoms.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105058"},"PeriodicalIF":3.3,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695206","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":"Empirical investigations of measures to reduce thermal risks to patients induced by high pressure gas supply lines during MRI-guided cryoablations at 1.5 T","authors":"Kevin J. Treb,&nbsp;Liqiang Ren,&nbsp;David A. Woodrum,&nbsp;Christopher P. Favazza,&nbsp;Scott M. Thompson,&nbsp;Daniel A. Adamo,&nbsp;Krzysztof R. Gorny,&nbsp;Aiming Lu","doi":"10.1016/j.ejmp.2025.105062","DOIUrl":"10.1016/j.ejmp.2025.105062","url":null,"abstract":"<div><h3>Purpose</h3><div>To investigate thermal injury risks from either radiofrequency (RF)-heating or excessive cooling by high-pressure gas supply lines (HPGSL) during MRI-guided cryoablations, and to identify clinically viable safety precautions.</div></div><div><h3>Materials and Methods</h3><div><em>Ex vivo</em> experiments were performed on a 1.5 Tesla MRI scanner utilizing an MRI conditional cryoablation system. A cryoneedle was inserted into a porcine tissue specimen with an HPGSL routed out of the scanner along the tissue surface and either connected to or disconnected from the ablation system. Experiments were performed with varied layers of operating room (OR) towels or a 2.5 cm thick foam pad between the HPGSL and tissue. Fiber-optic sensors were used to measure temperatures on the HPGSL surface, cryoneedle, and tissue surface during MRI at different specific absorption rates (SAR) or during active freezing.</div></div><div><h3>Results</h3><div>During MRI, tissue surface temperatures nearest the HPGSL increased by up to 40.7 ± 6.9 °C. Tissue temperature increases were reduced to less than 0.1°C as thicker insulation with OR towels or the foam pad were added between the HPGSL and tissue. Disconnecting the HPGSL reduced tissue heating near the HPGSL by 47 %. Tissue heating decreased linearly with decreased SAR. During freezing, the HPGSL cooled to 53.3 ± 1.2 °C below room temperature of 20.9°C. With the foam pad added, the tissue surface cooled to 1.2 ± 0.2 °C below room temperature.</div></div><div><h3>Conclusion</h3><div>During MRI-guided cryoablations the HPGSL poses significant patient risks of RF-burns or frostbite, which can be mitigated by ensuring adequate distance between the HPGSL and tissue using insulating materials.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105062"},"PeriodicalIF":3.3,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687567","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":"Safire CT iterative reconstruction protocol to reduce patient effective dose on PET/CT examinations","authors":"Alice Ferretti ,&nbsp;Sotirios Chondrogiannis ,&nbsp;Jlenia Peretto ,&nbsp;Anna Margherita Maffione ,&nbsp;Paola Bartoletti ,&nbsp;Luca Urso ,&nbsp;Luigi Manco ,&nbsp;Marcello Gava ,&nbsp;Maria Cristina Marzola","doi":"10.1016/j.ejmp.2025.105059","DOIUrl":"10.1016/j.ejmp.2025.105059","url":null,"abstract":"<div><h3>Introduction</h3><div>To implement the use of CT iterative reconstruction, instead of standard FBP, in order to reduce the patient dose of the 18F-FDG PET/CT examinations, preserving image quality and SUV accuracy.</div></div><div><h3>Methods</h3><div>Catphan 600 and Alderson-Rando anthropomorphic phantom were used to evaluate the SAFIRE iterative CT reconstruction on Siemens Biograph mCT system, progressively reducing the<!--> <!-->CareDose4D Quality-Ref-mAs. The PET quantitative accuracy was also evaluated by NEMA2012 IQ phantom. The optimized CT reconstruction protocol was applied in clinical setting on additional segmental PET/CT scan, after standard whole body PET/CT, for qualitative evaluation by two nuclear medicine physicians.</div></div><div><h3>Results</h3><div>Measurements on Cathpan phantom demonstrated that<!--> <!-->Safire reconstruction level 3 allowed to reduce the CT dose of about 40% without worsening the noise and CNR. For mAs-modulated acquisitions on the anthropomorphic phantom, a 30% reduction of dose<!--> <!-->using<!--> <!-->Safire at level 3<!--> <!-->does not worsen image quality in any anatomical part.</div><div>Analysing PET/CT acquisitions of NEMA IQ phantom with standard CT FBP reconstruction vs dose-optimized CT iterative reconstruction, the SUV values showed very small deviations (&lt;0.6 %).</div><div>The clinical evaluation carried out on 25 patients demonstrates the non-inferiority of the image quality obtained with the reduced CT dose and Safire 3 iterative reconstruction protocol compared to the reference CT dose and FBP reconstruction.</div></div><div><h3>Conclusions</h3><div>The use of the Safire iterative reconstruction at level 3 in whole-body PET/CT acquisition allowed an effective dose reduction of 1.8 mSv in mean (from 10.1 mSv to 8.3 mSv, p &lt; 0.001), without any detriment of image quality and SUV accuracy.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"136 ","pages":"Article 105059"},"PeriodicalIF":3.3,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687566","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}