Journal of Applied Clinical Medical Physics最新文献

{"title":"Developing reference plans for evaluating global clinical trials credentialing and PSQA systems","authors":"Fre'Etta M. D. Brooks,&nbsp;Mohammad Hussein,&nbsp;Jessica Lye,&nbsp;Christopher L. Nelson,&nbsp;Nakamura Mitsuhiro,&nbsp;Mallory C. Glenn,&nbsp;Patricia Diez,&nbsp;Rushil Patel,&nbsp;Maddison Shaw,&nbsp;Ileana Silvestre Patallo,&nbsp;Miriam Barry,&nbsp;Catharine H. Clark,&nbsp;Joerg Lehmann,&nbsp;Stephen F. Kry","doi":"10.1002/acm2.70113","DOIUrl":"10.1002/acm2.70113","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To develop a practical framework for creating a diverse set of validated reference plans (varying in complexity) and implement a workflow to introduce beam modeling, calibration, and delivery errors into the reference cohort to test and compare various dosimetry audit methodologies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Sixteen IMRT and VMAT reference plans were created, using RayStation software, for four phantom geometries based on established credentialing cases from participating Global Harmonization Group (GHG) members. These reference plans were first validated in a multi-ion-chamber phantom. Nine dosimetric errors (perturbations) were introduced into the plans by modifying beam model and/or delivery parameters (MLC-offset, MLC-transmission, leaf-tip-width, PDD, beam calibration, and MLC-position) based on documented community distributions of errors; this produced 144 plans. The dose impact on the clinical target volume (CTV) and organs at risk (OARs) was determined, and a range of classifications was developed to determine if the perturbed plan should pass or should fail an audit.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Introducing errors into the reference plans impacted each plan differently. Dose perturbations ranged from &lt;1% to &gt;10% in the mean dose to the CTV and &lt;10% to &gt;30% in the near maximum dose to OAR (D0.03). The 144 plans included clear “acceptable” and “unacceptable” scenarios, with significant changes in dose (relative to baseline reference values), as well as near pass/fail threshold results. Plan complexity was found to have a strong impact on dose deviation, and the mean MLC Gap metric was found to best capture this relationship.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This study presented a framework to develop a set of reference plans and perturbations that can be used to assess and compare various audit and PSQA methodologies. The GHG has developed this framework as part of our ongoing work to test the comparability of their audit systems; this framework supports our work of aligning international dosimetry audits across the globe.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 7","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70113","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144173852","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":"Dosimetric evaluation and clinical application of collimated apertures with proton beam line scanning in stereotactic radiotherapy","authors":"Chen-Yu Chou,&nbsp;Hsiao-Chieh Huang,&nbsp;Shen-Hao Lee,&nbsp;Shih-Ming Hsu","doi":"10.1002/acm2.70128","DOIUrl":"10.1002/acm2.70128","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Stereotactic radiotherapy (SRT) is a highly effective treatment with precision for small, localized lesions. Proton therapy, characterized by the Bragg peak, offers superior dose conformity compared to photon-based approaches. However, challenges remain in minimizing lateral penumbra and optimizing dose delivery, particularly for small targets. This study presents the first clinical application of collimated apertures integrated with the proton line scanning technique for proton stereotactic radiotherapy (PSRT). The aim was to evaluate the dosimetric advantages and clinical feasibility of this innovative approach.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Over a 1-year period, 30 patients with small lesions, including choroid melanoma and arteriovenous malformations, were treated using proton line scanning. Two planning strategies were evaluated: uncollimated proton line scanning (UPLS) and collimated proton line scanning (CPLS), incorporating patient-specific apertures. Dosimetric comparisons were conducted using the Homogeneity Index (HI), Paddick Conformity Index (CI_Paddick), Gradient Index (GI), and R50%. Treatment accuracy was validated using absolute dose measurements and Gamma Passing Rate (GPR) analysis under the criteria of 3%/3 and 2%/2 mm.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Plans incorporating customized collimated apertures showed significant improvements in dose conformity, with higher CI_Paddick values (<i>p</i> &lt; 0.001), and exhibited steeper dose fall-off, as reflected in lower GI and R50% values (<i>p</i> &lt; 0.001). A trend toward more homogeneous dose distributions was also observed (<i>p</i> &lt; 0.001). GPR analysis confirmed high treatment accuracy, with an average value of 99.00 ± 1.83% (3%/3 mm) and 91.06 ± 4.91% (2%/2 mm).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Integrating customized collimated apertures with proton beam line scanning is clinically feasible, improving precision, dose conformity, and healthy tissue sparing in PSRT. These findings support adopting this novel approach to advance precision proton therapy for small lesions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 7","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70128","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144173853","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":"Demonstration of an enhanced dosing pattern for debulking large and bulky unresectable tumors via differential hole-size spatially fractionated radiotherapy","authors":"Joshua Misa,&nbsp;William St. Clair,&nbsp;Damodar Pokhrel","doi":"10.1002/acm2.70127","DOIUrl":"10.1002/acm2.70127","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose/objective&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;We propose a novel lattice deployment for spatially fractionated radiotherapy (SFRT) treatments. In this approach, a larger diameter high-dose sphere is centrally placed in the bulky tumor mass and surrounded by smaller diameter high-dose spheres.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Materials/methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Thirty SFRT patients (10 head and neck [HN], 10 abdominal/pelvis, and 10 chest/lung cases) treated with an MLC-based crossfire method were retrospectively analyzed. Eleven differential hole-size lattice patterns were benchmarked against the clinically delivered SFRT plans (1 cm diameter cylinders, 2 cm spacing) and the standard uniform lattice pattern (1.5 cm diameter spheres, 3 cm spacing). These patterns varied in core diameter (C: 2–4 cm), spacing (S: 2–4 cm), and peripheral diameter (P: 1–2 cm). In addition to peak-to-valley-dose ratio (PVDR), tumor dose metrics (D&lt;sub&gt;50%&lt;/sub&gt;, V&lt;sub&gt;50%&lt;/sub&gt;, D&lt;sub&gt;mean&lt;/sub&gt;)&lt;sub&gt;,&lt;/sub&gt; D&lt;sub&gt;max&lt;/sub&gt; to nearby critical organs, and ablative dose (V&lt;sub&gt;75%&lt;/sub&gt;/V&lt;sub&gt;50%&lt;/sub&gt; and V&lt;sub&gt;15Gy&lt;/sub&gt;) were evaluated.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Results&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;10 out of 11 differential hole-size patterns showed increases in D&lt;sub&gt;50%&lt;/sub&gt;, D&lt;sub&gt;mean&lt;/sub&gt;, and V&lt;sub&gt;50%&lt;/sub&gt; compared to the standard lattice pattern. One pattern (C = 3 cm, S = 2 cm, P = 1.5 cm) outperformed the clinical SFRT plans in D&lt;sub&gt;50%&lt;/sub&gt; (Δ = 1.8 Gy, &lt;i&gt;p&lt;/i&gt; = 0.003; Δ = 2.0 Gy, &lt;i&gt;p&lt;/i&gt; = 0.015; Δ = 0.9 Gy, &lt;i&gt;p&lt;/i&gt; = 0.045), D&lt;sub&gt;mean&lt;/sub&gt; (Δ = 1.6 Gy, &lt;i&gt;p&lt;/i&gt; = 0.003; Δ = 1.7 Gy, &lt;i&gt;p&lt;/i&gt; = 0.021; Δ = 0.7 Gy, &lt;i&gt;p&lt;/i&gt; = 0.042), and V&lt;sub&gt;50%&lt;/sub&gt; (Δ = 20.4%, &lt;i&gt;p&lt;/i&gt; &lt; 0.001; Δ = 16.6%, &lt;i&gt;p&lt;/i&gt; = 0.008; Δ = 10.3%, &lt;i&gt;p&lt;/i&gt; = 0.079) for the HN, abdominal/pelvis, and chest/lung SFRT patients, respectively. This pattern also demonstrated average increases to D&lt;sub&gt;5%&lt;/sub&gt; D&lt;sub&gt;10%&lt;/sub&gt;, D&lt;sub&gt;90%&lt;/sub&gt; across all 30 patients compared to both benchmarked patterns. However, this pattern showed reduced PVDR compared to the clinical and standard SFRT plans but still achieved a ratio &gt; 3.0. All differential hole-size patterns demonstrated decreases in D&lt;sub&gt;max&lt;/sub&gt; to critical organs compared to the clinical SFRT plans. Moreover, compared to the clinical SFRT and the standard lattice plans, 9 out of 11 differential hole-size patterns demonstrated increases in V&lt;sub&gt;75%&lt;/sub&gt;/V&lt;sub&gt;50%&lt;/sub&gt; and V&lt;sub&gt;15Gy&lt;/sub&gt;.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Conclusion&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;All differential hole-size SFRT replans were clinically acceptable, with C = 3 cm, S = 2 cm, and P = 1.5 cm p","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 7","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144150482","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":"The burden of burnout: Understanding its prevalence and organizational drivers in medical physics","authors":"Deborah Schofield,&nbsp;C. Lynn Chevalier,&nbsp;Laurence Court,&nbsp;William Harmsen,&nbsp;Akiva Turner","doi":"10.1002/acm2.70121","DOIUrl":"10.1002/acm2.70121","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Burnout is a work-related syndrome characterized by increased levels of emotional exhaustion (EE) and depersonalization (DP) along with decreased levels of personal achievement. In the healthcare setting, higher burnout levels have been associated with negative impacts on personnel, an increased risk of errors, and a decrease in the quality of delivered care.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>The purpose of this study was to assess the prevalence of burnout among medical physicists working in the United States. Additionally, the impact of personal and organizational features on burnout risk was examined.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The anonymous survey was distributed to 1962 full members of the American Association of Physicists in Medicine. The survey consisted of seven demographic questions, the validated Maslach Burnout Inventory (MBI), and an organizational assessment tool. Burnout risk was evaluated using two different scoring methods. Inferential statistics were employed to examine the relationship between burnout and personal features, such as practiced sub-specialty, and organizational features, including the respondent's assigned facility safety score.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 337 responses were received, and 59.9% of medical physicist participants scored high on at least one burnout domain. A statistically significant association was found between the EE and DP burnout domains and personal factors, including working as a therapy medical physicist, working longer hours, and a moderate or significant impact on work-related feelings due to the COVID-19 pandemic. A statistically significant relationship was identified between all three burnout domains and the respondent's assigned facility safety score. Amongst therapy physicists, an inverse relationship was observed between all three burnout domains and both the teamwork and staffing constructs, as well as the open communication and punitive concerns construct.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Medical physicists in the United States are experiencing significant levels of burnout. Importantly, this study identified a link between quantitative burnout scores and facility safety, stressing the importance of addressing burnout.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144110750","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":"Beam model development and clinical experience with RadCalc for treatment plan quality assurance in online adaptive workflow with an MR-linac","authors":"Urszula Jelen,&nbsp;Zoë Moutrie,&nbsp;Jack D Aylward,&nbsp;Michael G Jameson","doi":"10.1002/acm2.70125","DOIUrl":"10.1002/acm2.70125","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>The aim of this work was to report on the optimization, commissioning, and validation of a beam model using a commercial independent dose verification software RadCalc version 7.2 (Lifeline Software Inc, Tyler, TX, USA), along with 4 years of experience employing RadCalc for offline and online monitor unit (MU) verification on the Elekta Unity MR-linac (MRL) for a range of clinical sites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Calculation settings and model parameters, including the Clarkson integration settings and radiation/light field offset, have been systematically examined and optimized, and pitfalls in the use of density inhomogeneity corrections and in off-axis calculations were investigated and addressed. The resulting model was commissioned by comparing RadCalc calculations to measurements for a variety of cases, selected following relevant recommendations, ranging from simple fields in a water tank to end-to-end point dose measurements in an anthropomorphic phantom.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For simple geometries, the agreement was within 2%, and for complex geometries, within 5%. When validating against the Monaco (Elekta AB, Stockholm, Sweden) treatment planning system (TPS), for 39 clinical commissioning plans, the mean total point dose difference was −0.3 ± 0.8% (−2.0%–1.1%). Finally, when applied retrospectively to 4085 clinical plan calculations, the agreement with the TPS was 0.3 ± 1.1% (−4.8%–4.2%), with fail rates of 0.1% for total point dose (discrepancy &gt; 4%) and 0.3% for individual fields (discrepancy &gt; 10%).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Improved calculation agreement with the TPS and therefore increased confidence in the online QA, opened the way for an automated and physics-light independent MU verification workflow within our MRL program.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 7","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70125","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144093838","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":"AAPM Task Group No. 249.B—Essentials and guidelines for clinical medical physics residency training programs","authors":"Jonathon A. Nye,&nbsp;Joseph P. Dugas,&nbsp;William D. Erwin,&nbsp;David P. Gierga,&nbsp;Darryl G. Kaurin,&nbsp;Stephanie M. Leon,&nbsp;Ho-Ling Anthony Liu,&nbsp;Zheng Feng Lu,&nbsp;Alphonso W. Magri,&nbsp;Lynn N. Rill,&nbsp;Leah K. Schubert,&nbsp;Beth A. Schueler,&nbsp;Irina Vergalasova,&nbsp;John Vetter,&nbsp;Brian D. Wichman,&nbsp;Amy Shu-Jung Yu,&nbsp;Dandan Zheng","doi":"10.1002/acm2.70111","DOIUrl":"10.1002/acm2.70111","url":null,"abstract":"<p>The establishment of guidelines and curriculum standards for medical physics residency training is a critical component of setting expectations and competencies for the profession. Since the last publication of these standards, residency training has become integrated into the eligibility criteria for most medical physics certification bodies. The rapid growth of medical physics requires periodic review of the curriculum to remove outdated approaches, update established knowledge, and add emerging technologies. The goal of this document is to provide a reference standard for residency training program directors, training mentors, and residents to guide creation and/or optimization of their program's curriculum. The document is intentionally forward-looking to capture emerging technological advances including hybrid diagnostic and therapeutic delivery systems and applications of image processing. This document is an update of the current residency training curriculum.</p><p>Version history of residency training guidelines</p><p>Publication Title</p><p>Date</p><p>2013 Essentials and Guidelines for Clinical Medical Physics Residency Training Programs—AAPM Report No. 249</p><p>2006 Essentials and Guidelines for Hospital-Based Medical Physics Residency Training Programs—Report No. 90</p><p>1992 Essentials and Guidelines for Hospital-Based Medical Physics Residency Training Programs—Report No. 36</p><p>The Work Group on Periodic Review of Medical Physics Residency Training (WGMPRT) would like to acknowledge the authors of past versions of this document as they form the basis for this update. It is the sincere hope of the WGMPRT that this report will continue to be used by the medical physics community to guide training in the profession.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144093829","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":"Quantitative quality control of 3D water tank using image analysis","authors":"Yuki Tanimoto,&nbsp;Kohei Sugimoto,&nbsp;Kazunobu Koshi,&nbsp;Akira Hiroshige,&nbsp;Shohei Yoshida,&nbsp;Yoshiki Fujita,&nbsp;Atsuki Nakahira,&nbsp;Daiki Nakanishi,&nbsp;Hirofumi Honda,&nbsp;Masataka Oita","doi":"10.1002/acm2.70119","DOIUrl":"10.1002/acm2.70119","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background and objective</h3>\u0000 \u0000 <p>Accurate beam data acquisition using three-dimensional (3D) water tanks is essential for beam commissioning and quality control (QC) in clinical radiation therapy. This study introduces a novel method for quantitative QC of the system, utilizing MV images and webcam videos. The stability of the motor drive speed and the positional accuracy of the fixture were evaluated under two measurement modes: “continuous mode” and “step-by-step mode.”</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A TRUFIX mounting system (PTW Freiburg Inc., Germany) was used to attach the center of the steel ball to its top, ensuring alignment with the water surface of the tank. To assess deviations from the radiation isocenter, MV images were acquired and compared with digitally reconstructed radiographs (DRRs). These evaluations were performed at different speed settings (slow, medium, and fast) using ET CT Body Marker (BRAINLAB Inc., USA) mounted on the drive unit. A webcam was utilized to capture the images, and custom-developed tracking software was employed to analyze deviations in driving speed and positional errors.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The mean error of the radiation isocenter was 0.37 ± 0.09 mm. As the motor drive speed increased, the discrepancy between the set speed and the actual speed observed in the analysis also became larger. In “continuous mode,” the deviation from the displayed value was greater than that observed in “step-by-step mode.”</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>It is demonstrated that the proposed analysis method can quantitatively evaluate radiation isocenter misalignment, tank setup position deviation, and both the indicated drive speed values and their stability. At higher drive speeds, the “step-by-step mode” showed smaller deviations from the indicated values.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144101910","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 internal target volume of abdominal tumors using cine-MRI","authors":"Jessica Lye,&nbsp;Reza Alinaghi-Zadeh,&nbsp;Sandie Fisher,&nbsp;Nikki Shelton,&nbsp;Glenn Cahoon,&nbsp;Leah McDermott,&nbsp;Richard Khor,&nbsp;Kym Rykers,&nbsp;Sweet Ping Ng","doi":"10.1002/acm2.70097","DOIUrl":"10.1002/acm2.70097","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>The detailed anatomy visualization with magnetic resonance (MR)-guided radiotherapy is particularly attractive for abdominal treatments, but patient respiratory motion can compromise image quality. The “navigator technique” produces high-quality 3D images, triggered by diaphragm displacement, in exhale phase only. The gold standard for planning is 4D imaging, which visualizes the lesion for all breathing phases. When 4D imaging is not available, an alternative is using 3D imaging combined with motion information from cine-MR.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This work investigates two alternative internal target volume (ITV) generation methods and compares them with the original treatment 4DCT imaging ITV. Datasets were analyzed from 10 upper abdominal patients that originally had been treated with a 4DCT-based ITV. In addition to the 4DCT, these patients received an exhale MR and cine-MR scans prior to treatment. An MR-CT-compatible motion phantom was also used to compare the two alternative ITV methods with the clinical 4DCT method. The first ITV method uses “margins expansion” (ME method) asymmetrically. The second method duplicates the exhale gross tumor volume (GTV) and shifts it to the positions of the average inhale GTV and mid-position GTV. The ITV is the “Boolean combine” (BC method) of the three displaced GTVs. The ME and BC methods were compared with the clinical 4DCT method using the Dice similarity coefficient (DSC) to determine the impact of approximating the true GTV trajectory and neglecting deformation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The ITV DSC ranges were 73%–96% for the ME method and 76%96% for the BC method. The BC approach created smaller treatment volumes than the ME method and more closely resembled the 4DCT margin for cases with larger motion and a significant component in the anterior–posterior direction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>An exhale MR combined with cine-MR can be used to simply create an ITV for adaptive MR-guided radiotherapy. For small lesions with larger anterior motion, the Boolean Combine method is the more accurate method.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70097","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144020168","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":"Empowering young minds through STEM education: Engaging high schoolers in Ghana through medical physics","authors":"Afua A. Yorke,&nbsp;Mercy T. Schandorf,&nbsp;Abigail N. M. Quaye,&nbsp;Peniel Tenkorama Twum,&nbsp;Bishwambhar Sengupta,&nbsp;Kwadwo Nkansah-Poku,&nbsp;Juliana A. Kplorfia,&nbsp;Jessica Fagestrom","doi":"10.1002/acm2.70126","DOIUrl":"10.1002/acm2.70126","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To promote diversity in Science, Technology, Engineering, and Mathematics (STEM), an educational presentation and hands-on session was organised to raise awareness of STEM career opportunities among high school girls to introduce the students to the field of medical physics.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>The study involved 65 first-year Senior High School girls, aged 13–16, pursuing general science in Accra, Ghana. This initiative, organised by the Girls Excellence Movement (GEM) in collaboration with a United States (US) institution, implemented the “<i>heroes in radiation oncology</i>” program, which included a relatable presentation and hands-on experience in simulation to treatment planning activities. The program's effectiveness was assessed through pre-and post-assessment surveys, and a thematic analysis of student feedback.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Participants' awareness of career fields showed an interest in traditional healthcare professions (92%) and engineering (73.8%), with minimal medical physics awareness (12.3%). Post-presentation survey showed a significant change in participants' perception of medical physics 87.3%. Thematic analysis revealed increased awareness, understanding, and interest, dispelled misconceptions about radiation safety, and highlighted the interdisciplinary nature and career opportunities. The presentation was successful in inspiring participants and expanding their perspectives on medical physics.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The program raised awareness of medical physics among participants, many of whom were previously unfamiliar with the field. Participants reported a newfound understanding of the interdisciplinary nature of medical physics, its connections to biology, mathematics, and engineering.This program can easily be reproduced in community and school outreaches.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70126","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982036","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":"Enhanced analysis of gating latency in 0.35T MR-linac through innovative time synchronization of a motion phantom and plastic scintillation detector","authors":"Mateb Al Khalifa,&nbsp;Tianjun Ma,&nbsp;Haya Aljuaid,&nbsp;Siyong Kim,&nbsp;William Y. Song","doi":"10.1002/acm2.70116","DOIUrl":"10.1002/acm2.70116","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study aims to evaluate how different gantry angles, breathing rates (BPM), cine image speeds, and tracking algorithms affect beam on/off latency and the subsequent impact on target dose for a 0.35T MR-Linac with a 6 MV FFF beam. The investigation incorporates an image-based MRI4D modus QA motion phantom (MQA) and a measurement-based plastic scintillation detector (PSD).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The MQA's target was customized with an insertion for a 1 mm PSD from BluePhysics. Both the PSD and the MQA were simultaneously synchronized to the Linac to capture latency signals. A plan was created in the ViewRay TPS to deliver dose to the target at three gantry angles (0°, 120°, and 240°). Each gantry angle was evaluated at three breathing rates (10, 12, and 15 BPM). The study also examined two imaging speeds (4 and 8 FPS) and four tracking algorithms.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Across all configurations at 4 FPS, the overall mean beam-on latency was 0.339 ± 0.06 s from the PSD and 0.318 ± 0.06 s from the MQA, whereas at 8 FPS it was 0.630 ± 0.07 s (PSD) and 0.609 ± 0.07 s (MQA). Conversely, the overall mean beam-off latency at 4 FPS was 0.153 ± 0.03 s (PSD) and 0.124 ± 0.03 s (MQA), while at 8 FPS it was 0.121 ± 0.06 s (PSD) and 0.205 ± 0.04 s (MQA). The overall mean difference between gating and non-gating doses was an increase of 12.050 ± 9.2 cGy at 4 FPS and 14.044 ± 7.4 cGy at 8 FPS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This comprehensive study underscores the significant influence of gantry angle, breathing rate, cine imaging speed, and tracking algorithms on latency and dose delivery accuracy in a 0.35T MR-Linac.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"26 7","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144013095","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}