Journal of Applied Clinical Medical Physics最新文献

{"title":"A model-based method for reporting mammographic diagnostic reference levels for any compressed breast thickness: A refined reporting approach","authors":"Ahmad A. Alhulail,&nbsp;Salman M Albeshan,&nbsp;Maha M. Almuqbil","doi":"10.1002/acm2.70206","DOIUrl":"https://doi.org/10.1002/acm2.70206","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Mammography is a critical tool for early breast cancer detection, but its use of ionizing radiation necessitates careful monitoring and optimization of patient exposure to ensure safety. Conventional methods for reporting diagnostic reference levels (DRLs) rely on wide compressed breast thickness (CBT) ranges, which lack the precision to account for individual variations, limiting their effectiveness in optimizing mammographic radiation doses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To develop an equation-based approach that provides a DRL for any given CBT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The 75th percentile of median average glandular dose (AGD) values from nine centers (a total of 187,704 mammograms) was employed for the DRL estimation using three approaches: (1) estimating a DRL for a CBT range assumed to represent typical women in the population (simplest/common approach), (2) reporting DRLs per different 10-mm CBT ranges (improved approach), and (3) as a DRL equation (the proposed approach), which was generated from fitting the values of the estimated DRLs versus each corresponding CBT. The differences in these approaches’ results were compared.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For our population, the curve fitting of the DRLs versus their corresponding CBTs resulted in a bi-exponential equation with high-fitting reliability (<i>R</i>² &gt; 0.98). The equation approach provides continuous DRL values to serve any given CBT. The difference in the estimated DRLs by the equation approach and the improved range-based reporting approach can range between several percentages to more than 35% and can exceed that to more than 175% when compared with the estimated simplest approach's DRL.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The proposed DRL equation approach is reliable and can be used to provide more precise results for any given CBT value rather than the conventional range-based reporting approaches. Vendors can adopt the proposed approach by integrating an option to input DRL equations to automate the optimization of mammographic dose.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of intra-fractional target displacement by patient motion during a single-isocenter multi-target stereotactic radiation therapy for brain metastases","authors":"Ryota Yamada,&nbsp;Takaaki Yoshimura,&nbsp;Ryo Murata,&nbsp;Kentaro Nishioka,&nbsp;Takashi Mori,&nbsp;Fuki Koizumi,&nbsp;Yoshihiro Fujita,&nbsp;Shuhei Takahashi,&nbsp;Takahiro Hattori,&nbsp;Takahiro Kanehira,&nbsp;Kohei Yokokawa,&nbsp;Rie Yamazaki,&nbsp;Kenji Horita,&nbsp;Hiroshi Tamura,&nbsp;Yamato Wakabayashi,&nbsp;Yuta Ichiu,&nbsp;Takayuki Hashimoto,&nbsp;Hidefumi Aoyama","doi":"10.1002/acm2.70219","DOIUrl":"https://doi.org/10.1002/acm2.70219","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Single-isocenter multi-target volumetric modulated arc therapy (SIMT-VMAT) has been implemented widely in fractionated stereotactic radiosurgery (fSRS) to treat brain metastases. The impact of rotational intra-fractional patient motion (IFPM) is influenced by the distance between the geometric target's center and the isocenter (DTI).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>We hypothesized that IFPM's impact on each target would increase with greater DTI during fSRS. Therefore, we aimed to estimate the intra-fractional target displacement (IFTD), which represents each target's displacement caused by translational and rotational components of IFPM.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this study, we involved 35 patients with 2–13 brain metastases, all of whom had previously undergone SIMT-VMAT fSRS. All patients were immobilized using a clamshell-style device, with 28 using a biteplate. Cone beam computed tomography (CBCT) images were obtained at the same imaging center before and after treatment. The IFPM was calculated using both CBCT datasets. The IFTD was determined by comparing the planned target coordinates with the actual coordinates while factoring in IFPM.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We evaluated 136 targets. The mean IFTD was 0.38 mm (95% confidence interval [CI]: 0.37–0.40 mm) with the biteplate and 0.65 mm (95% CI: 0.59–0.71 mm) without it. A very weak positive correlation was observed between DTI and IFTD despite the immobilization method. This correlation indicates that the distance dependence of IFTD is nearly negligible.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The findings showed that the impact of IFPM on each target demonstrated minimal dependence on the DTI. Displacement was relatively consistent regardless of the target location. In addition, the use of a biteplate was suggested to potentially reduce these effects.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70219","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of dose-volume calculation accuracy for intracranial stereotactic radiosurgery with volumetric-modulated arc therapy using analytical and clinical treatment plans","authors":"Ioanna Grammatikou,&nbsp;Alexandra Drakopoulou,&nbsp;Antigoni Alexiou,&nbsp;Georgios Pissakas,&nbsp;Pantelis Karaiskos,&nbsp;Vasiliki Peppa","doi":"10.1002/acm2.70235","DOIUrl":"https://doi.org/10.1002/acm2.70235","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Stereotactic radiosurgery (SRS) poses challenges in calculating dose volume histograms (DVHs) due to the inherent spatial discretization uncertainties.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To develop a procedure for quantifying discretization errors and assessing DVH accuracy in intracranial SRS applications.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The capability of Monaco Treatment Planning System (TPS) to calculate structure and isodose volumes using slice thickness (ST) and dose grid (DG) of 1 mm was validated against analytical values, and in-house calculations performed for 15 patients with brain metastases diameters ranging from 6 to 30 mm treated with a VMAT technique. For these patients, STs of 1.5 and 2 mm, and DGs of 2 and 3 mm were also explored to establish clinically acceptable thresholds, using isodose volume calculations and clinically relevant DVH indices.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Monaco TPS presented an excellent performance in calculating structure and isodose volumes for the 1-mm ST and DG, with an average percentage difference compared to analytical and in-house calculations within 2.1%. For the clinical treatment plans, switching to 2 and 3-mm DGs led to statistically significant differences compared to 1-mm DG across all the considered indices, yet the variations between the 1 and 2-mm DGs remained under 5% when target diameters exceeded 20 mm. Although no statistical differences were observed between the calculated indices when different STs were considered, clinically significant differences were observed in selected cases with lesion diameters smaller than 20 mm.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Monaco TPS demonstrated excellent performance in calculating structure and isodose volumes pertinent to SRS applications using 1-mm ST and DG, while adherence to 1-mm ST and DG should be maintained in clinical cases, unless target diameters surpass 20 mm, where STs and DGs up to 2 mm could be also utilized. The method developed in this study could act as a quality assurance procedure in order to establish clinically relevant discretization thresholds for SRS platforms.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70235","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical utility of consecutive volume scanning dual-energy CT in differentiating hemorrhage from contrast staining in ischemic stroke patients","authors":"Aroon Pressram,&nbsp;Reordan DeJesus,&nbsp;Tara Massini,&nbsp;Anna Y. Khanna,&nbsp;Manuel Arreola,&nbsp;Izabella L. Barreto","doi":"10.1002/acm2.70209","DOIUrl":"https://doi.org/10.1002/acm2.70209","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background and Purpose</h3>\u0000 \u0000 <p>Accurate differentiation between hemorrhage and iodinated contrast staining is critical for managing ischemic stroke patients following revascularization. While dual-energy CT (DECT) has shown promise in this context, studies have predominantly focused on dual-source or fast-kV switching systems. This study evaluates the diagnostic accuracy of a sequential axial scanning DECT system for assessing hemorrhagic transformations of ischemic stroke patients after having received thrombolytic therapy and/or endovascular procedures using MRI as the gold standard.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>A retrospective cohort of 97 ischemic stroke patients underwent DECT imaging within 24 h post-revascularization, followed by MRI within 48 h. Patient hemorrhage types were classified based on the Heidelberg classification using MRI as a ground truth. DECT performance was assessed by calculating sensitivity, specificity, and predictive values for hemorrhage classes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Of the 97 DECT examinations, 25 (25.8%) showed a hyper density in the DECT images compared to 31 (32.0%) hyper densities identified by MRI. DECT achieved 100% sensitivity for larger hemorrhages that impact patient management (class 3) but lower sensitivity (61.0%) for smaller hemorrhages (class 1) with no false positives (100% specificity).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Sequential axial scanning DECT offers a reliable and accessible alternative to MRI for detecting clinically significant hemorrhages in acute stroke settings. Its ability to differentiate hemorrhage from contrast staining in a single session supports its integration into routine clinical workflows, enhancing timely decision-making and improving patient care.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70209","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current progress of digital twin construction using medical imaging","authors":"Feng Zhao,&nbsp;Yizhou Wu,&nbsp;Mingzhe Hu,&nbsp;Chih-Wei Chang,&nbsp;Ruirui Liu,&nbsp;Richard Qiu,&nbsp;Xiaofeng Yang","doi":"10.1002/acm2.70226","DOIUrl":"https://doi.org/10.1002/acm2.70226","url":null,"abstract":"<p>Medical imaging is fundamental to digital twin technology, enabling patient-specific virtual models of anatomy and physiology. By integrating high-resolution modalities (Magnetic Resonance Imaging (MRI), Computed Tomography (CT), Positron Emission Tomography (PET), ultrasound) with computational frameworks, recent imaging advances now support real-time simulation, predictive modeling, and earlier disease detection. Such capabilities directly inform individualized treatment planning and contribute to more precise, personalized care. Despite remaining challenges—complex anatomical modeling, multimodal integration, and high computational demands—recent advances in imaging and machine learning have significantly enhanced the accuracy and clinical utility of digital twins. The main contributions of our review are: (1) a system-by-system classification of methodologies; (2) evidence that advanced imaging modalities have improved diagnostic accuracy, treatment effectiveness, and patient outcomes beyond conventional approaches; and (3) identification of remaining technical bottlenecks. We further analyze key technical barriers—such as data scarcity and computational complexity—and outline future directions (e.g., AI-driven data augmentation, real-time model optimization) to unlock digital twins’ full potential in precision medicine.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70226","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of an EPID-based dose verification system for patient-specific quality assurance in a harmony device","authors":"Dohyeon Yoo,&nbsp;Hyunggun Lee,&nbsp;Sangmin Lee,&nbsp;Soorim Han,&nbsp;Taeho Kim,&nbsp;Changhwan Kim,&nbsp;Min Cheol Han,&nbsp;Jin Sung Kim","doi":"10.1002/acm2.70201","DOIUrl":"https://doi.org/10.1002/acm2.70201","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Precise patient-specific quality assurance (PSQA) is critically important in advanced treatments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study aimed to evaluate the performance of the RadCalc software's electronic portal imaging device (EPID)-based patient specific QA function, focusing on its ability to accurately reconstruct doses from EPID images acquired on the Elekta Harmony Pro linear accelerators (LINACs).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Beam modeling was conducted for 6-MV and 6-MV flattening filter–free (FFF) photon beams on the recently released Harmony Pro LINAC system in RadCalc. Volumetric modulated arc therapy (VMAT) plans for 6-MV (19 patients) and 6-MV FFF (10 patients) were generated using the ArcCHECK phantom to replicate clinical treatments. Dose calculations from RadCalc, using portal images, were compared to those generated by the treatment planning system (TPS) through gamma analysis at 1%/1, 2%/2, and 3%/3 mm, with a 90% minimum passing rate.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For 6-MV and 6-MV FFF beams, gamma analysis comparing EPID data with RadCalc showed a 98.83% passing rate at 2%/2 mm. For VMAT plans, 6-MV beams achieved the highest passing rate (99.88%) for the breast case at 3%/3 mm and the lowest (82.33%) for the lymphatic node case. Similarly, 6-MV FFF beams yielded the highest passing rate (99.87%) for the abdominal case at 3%/3 mm and the lowest (94.07%) for the bone case.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>RadCalc showed high accuracy for dose evaluation on the Elekta Harmony Pro LINAC. Beam modeling achieved a gamma passing rate of at least 98% (2%/2 mm), demonstrating reliable performance even under minor setup variations.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of NTCP metrics to identify unbalanced levels of dose trade-off between left lung and heart in lung cancer radiotherapy","authors":"Georgios Komisopoulos,&nbsp;Panayiotis Mavroidis,&nbsp;Fotini Simopoulou,&nbsp;George Kyrgias,&nbsp;Kiran Pant,&nbsp;Yiannis Roussakis,&nbsp;Kyriaki Theodorou","doi":"10.1002/acm2.70207","DOIUrl":"https://doi.org/10.1002/acm2.70207","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>The aim of this study is to determine the optimal level of dose trade-off between left lung and heart during plan optimization in lung cancer radiotherapy, and also to examine the impact of planning target volume (PTV) size in reducing the overall risk of toxicity of lung and heart.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This work includes 20 left-sided lung cancer patients and for each of them two VMAT plans (dosimetrically and radiobiologically optimized) were developed. In all the plans, a dose of 70 Gy in 35 fractions was prescribed to PTV. Each plan was evaluated in terms of PTV coverage, mean lung dose, lung-V₂₀, mean heart dose, and heart-V₅. The normal tissue control probability (NTCP) values of radiation pneumonitis and heart valve dysfunction were calculated using the Relative Seriality model.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The patients with PTV &lt; 300 cm³ had a left lung NTCP of 70.7 ± 14.6% and a heart NTCP of 11.5 ± 5.5%, whereas for the patients with PTV &gt; 300 cm³, the corresponding NTCP values were 86.0 ± 9.5% for left lung and 13.7 ± 4.9% for heart, respectively. After the NTCP-based optimization, for the patients with PTV &lt; 300 cm³, the corresponding lung NTCP values had a decrease of 12.8% and the heart NTCP values had an increase of 2.7%, whereas for the patients with PTV &gt; 300 cm³, the lung NTCP values had a decrease of 6.5% and the heart NTCP values had an increase of 3.9%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Our results indicate that there is a systematic unbalance in dose trade-off between left lung and heart, which varies based on the PTV size. NTCP metrics were found useful in identifying this issue.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of a model-based water-equivalent EPID image conversion algorithm for linac beam QA","authors":"Ivan Kutuzov,&nbsp;Boyd McCurdy","doi":"10.1002/acm2.70210","DOIUrl":"https://doi.org/10.1002/acm2.70210","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>The nonwater-equivalent energy response of electronic portal imaging devices (EPIDs) is a major obstacle to using them for linear accelerator (linac) beam parameter verification. In this study, we propose an EPID-based machine quality assurance (QA) application that uses a model-based radiation transport algorithm to convert EPID-measured images into water-equivalent dose distributions that can be used to assess beam flatness and symmetry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>An in-house developed, model-based radiation transport algorithm was used to estimate the incident beam fluence from measured EPID images and convert it into either 3D dose distributions in a virtual water tank or 2D water-equivalent dose distributions in a virtual ion chamber array. The conversion algorithm was validated using independent measurements in a scanning water tank and a reference ion chamber array under symmetric and also intentionally detuned (i.e., asymmetric) beam conditions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For symmetric fields, EPID-reconstructed percentage depth dose distributions (PDDs) agreed with water tank measurements to within 1% beyond the first 10 mm of depth. Beam profile comparisons showed differences within 1% in low dose-gradient regions. For all symmetric and intentionally asymmetric fields, beam flatness and symmetry derived from reconstructed images agreed with reference measurements to within 0.2% and 0.3%, respectively. The model demonstrated high sensitivity to the controlled beam asymmetries and steering distortions, with EPID-reconstructed metrics closely matching reference water-equivalent measurements and significantly outperforming metrics derived from raw EPID images.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The proposed model-based algorithm enables accurate conversion of EPID images into water-equivalent dose distributions, facilitating accurate determination of beam flatness and symmetry. This application addresses some limitations of the previously proposed EPID-based linac QA techniques, which are limited to nonwater-equivalent constancy checks, and supports the use of EPIDs as robust dosimetry tools for linac radiation beam parameter verification.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 8","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Digital twin creation of a proton therapy treatment environment with hybrid LiDAR and RGB 3D camera","authors":"Jingjing M. Dougherty,&nbsp;Erik J. Tryggestad,&nbsp;Chris J. Beltran","doi":"10.1002/acm2.70231","DOIUrl":"https://doi.org/10.1002/acm2.70231","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>This study evaluates the feasibility of utilizing a commercial-grade 3D LiDAR/RGB camera, combined with 3D reconstruction software, to create an accurate and hyper-realistic digital model of a proton therapy treatment room. This reconstructed model aims to enhance collision avoidance strategies and improve 3D machine model accessibility. Utilization of a 3D LiDAR/RGB camera as a radiotherapy environment modeling has not been reported prior.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To create a comprehensive 3D model of a half-gantry proton therapy system, colored point cloud data was captured using the Matterport Pro 3 camera, a hybrid LiDAR and RGB imaging system with high-resolution capabilities (134.2 MP), a 360° horizontal field of view, and 20 mm accuracy at 10 m. A total of 117 acquisition points, distributed across the treatment room with three camera heights, ensured complete coverage and minimal occlusions. Scanning, completed in under 3 hours, was monitored in real time using the Matterport App. Post-scan processing involved denoising and converting the point cloud into 3D mesh structures using MeshLab, followed by refined pair-wise iterative closest point (ICP) alignments. Textures and materials were assigned to reflect real-world objects, and a ray-tracing engine simulated realistic lighting in Blender. Animations illustrating the kinematics of the treatment couch and gantry were simulated in Blender for enhanced visualization.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The scanning process achieved complete data capture without missing information, attributed to strategic oversampling during data acquisition. The mean root mean square error (RMSE) of the ICP registration was 0.008 m. The validation process confirmed that the dimensions of the treatment couch within the digital model closely matched the actual measurements with less than 2 cm deviation, indicating high accuracy. The resulting digital twin provided a photorealistic and immersive representation of the proton therapy treatment room, serving as a valuable digital asset for various applications.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>It is possible to generate vendor-independent and highly accurate 3D models of the proton treatment room environment with a commercial grade LiDAR/RGB camera to expand future research opportunities and education endeavors.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 8","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70231","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel Cherenkov radiation removal method for plastic scintillator detectors in a 0.35 T MR-Linac","authors":"Mateb Al Khalifa,&nbsp;Tianjun Ma,&nbsp;Haya Aljuaid,&nbsp;Siyong Kim,&nbsp;William Y. Song","doi":"10.1002/acm2.70202","DOIUrl":"https://doi.org/10.1002/acm2.70202","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study evaluates methods for removing Cherenkov radiation (CR) from plastic scintillation detectors (PSDs), focusing on constraints specific to a 0.35 T MR-Linac system.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Five CR-removal methods were examined: cross calibration, fiber alone, multiloop, collimator rotation, and couch rotation. The first three (cross calibration, fiber alone, and multiloop) were tested on a 0.35 T MR-Linac (ViewRay Inc., USA) using the BluePhysics PSD (Blue Physics LLC, USA). These methods do not require collimator or couch rotation. The remaining two methods (collimator rotation and couch rotation) were tested on a Varian TrueBeam (Varian Medical Systems, USA) for comparison. Measurements were performed under various setup configurations, and Cherenkov radiation extraction (CRE) values were calculated to determine each method's effectiveness.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The multiloop approach yielded a CRE of 0.7288, making it the most practical and robust for MR-Linac constraints because it requires neither collimator nor couch rotation. The cross calibration and fiber alone methods produced CRE values of 0.7318 and 0.7569, respectively. Collimator rotation gave 0.7255, comparable to multiloop. In contrast, couch rotation resulted in 0.7489 but exhibited more variability, suggesting lower reliability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The multiloop method emerged as the most practical and robust technique for CR removal in 0.35 T MR-Linac systems. Its simplicity and compatibility with MR-Linac design constraints make it a highly effective approach for CR removal in PSD-based radiotherapy applications.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 8","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70202","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}