Journal of Applied Clinical Medical Physics最新文献

{"title":"A group-based hands-on seminar for teaching failure mode and effects analysis in CyberKnife stereotactic radiotherapy","authors":"Hiroyuki Okamoto, Shie Nishioka, Takeshi Kamomae, Kohei Okawa, Souichi Kikuchi, Junji Suzuki","doi":"10.1002/acm2.70789","DOIUrl":"10.1002/acm2.70789","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Risk analysis is becoming increasingly important in advanced radiotherapy, as treatment workflows grow more complex and require multidisciplinary expertise. Although failure mode and effects analysis (FMEA) has been recommended for risk-based quality management, opportunities for users to practically learn and apply FMEA within CyberKnife® workflows remain limited.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To evaluate the feasibility and educational value of a group-based, hands-on seminar for teaching FMEA methodology in CyberKnife® stereotactic radiotherapy, using four representative treatment sites as practical examples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A half-day seminar was conducted for eight radiation technologists and six medical physicists from CyberKnife® institutions, supported by four facilitators. Following a didactic lecture on risk analysis, participants were divided into four site-specific groups (intracranial, lung, spine, and prostate). Each group utilized institution-prepared process maps and a shared Excel-based worksheet to identify potential failure modes, score them using a five-point FMEA scale for occurrence, severity, and detectability, and discuss possible countermeasures. Risk priority numbers (RPNs) were calculated to rank the identified failure modes. A postseminar questionnaire was administered to assess participants’ prior experience, level of understanding of risk analysis, and willingness to implement it in clinical practice.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The seminar generated site-specific failure mode lists as educational outputs. The highest-ranked risks were contouring errors for intracranial lesions (RPN 48), irregular respiration for lung lesions (RPN 64), pain-induced patient motion for spinal lesions (RPN 36), and target delineation errors for prostate lesions (RPN 80). Other major risks included inappropriate selection of immobilization devices, prescription and fractionation errors, tracking-related issues, image registration inaccuracies, and incorrect patient-specific QA evaluation criteria. Thirteen participants completed the questionnaire. Most participants had limited prior experience with risk analysis; however, 85% reported a good level of understanding after the seminar, and 92% expressed willingness to implement risk analysis at their institutions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This group-based seminar pr","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70789","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148919811","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":"Towards adaptive radiotherapy: Comparing HyperSight and standard CBCT reconstructions on a C-Arm Linac","authors":"Niamh L. Clarke, Jeremy L. Hughes, Derrick Wanigaratne, Adam U. Yeo","doi":"10.1002/acm2.70786","DOIUrl":"10.1002/acm2.70786","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Cone-beam computed tomography (CBCT) is integral to image-guided radiation therapy and increasingly used for adaptive radiotherapy and CBCT-based dose calculation. Conventional kV-CBCT systems on C-arm TrueBeam linacs with Feldkamp–Davis–Kress (FDK) reconstruction have historically been limited by reduced Hounsfield Unit (HU) accuracy, scatter contamination, image noise and reconstruction artefacts. Iterative CBCT (iCBCT) reconstruction has improved image quality and HU consistency relative to the conventional FDK reconstruction. HyperSight represents a further evolution through software and hardware development with an enhanced detector design, advanced reconstruction algorithms and gantry rotation speeds up to 9°/s.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>This study reports commissioning and evaluation of HyperSight iterative CBCT (HS-iCBCT) acquired on a Varian TrueBeam (v4.1), to support adaptive workflows in comparison with standard (Std-FDK) and iterative CBCT (Std-iCBCT) on a TrueBeam (v2.7).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Material and methods</h3>\u0000 \u0000 <p>CBCT images were acquired on a Varian TrueBeam using the conventional kV On-board Imager (OBI) for Std-FDK and Std-iCBCT reconstructions and the HyperSight kV-imaging system for HS-iCBCT. Commissioning included CBCT dose calculation protocol optimization, CT-to-electron density (CT–ED) calibration and validation using STEEV, Rando and the CIRS Dynamic Thorax phantoms. CBCT images of anthropomorphic Head, Thorax/Spine, Rib and Lung phantoms were rigidly registered to the planning CT (pCT) and resampled using Velocity AI (v4.2). Voxel-wise HU difference histograms were generated, with peak position used to quantify systematic HU bias. Treatment plans (20 Gy/1# for Brain SRS/Spine, 24 Gy/2# for Rib and 54 Gy/3# for Lung) were optimized on the pCT and recalculated on the CBCT datasets. Dose–volume histogram (DVH) metrics were assessed and 3D-gamma analysis (2%/1 mm to 1%/1 mm; 10%/70% dose thresholds) was performed and compared with Std-FDK and Std-iCBCT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>HS-iCBCT showed improved HU accuracy compared with Std-iCBCT and Std-FDK when benchmarked against the pCT. For materials ≤ 1.08 g/cm<sup>3</sup>, the mean HU difference was lowest for HS-iCBCT at 7.7 ± 4.1 HU, compared with 23.6 ± 13.5 HU for Std-iCBCT and 38.0 ± 19.7 HU for Std-FDK (Friedman <i>p</i> < 0.05). For higher-density materials, HS-iCBCT demonstrated mean HU differences of 33.5 ± 22.9 HU, compared with 46.2 ± 22.2 HU for Std-iCBCT and 93.4 ± 57","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70786","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148919767","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":"Comparison of in-field secondary cancer risk based on therapeutic proton dose between proton arc therapy and intensity-modulated proton therapy in lung cancer patients","authors":"Yuankang Xu, Wenguang Chen, Junxiang Wu, Hao Guo, Fanrui Zeng, Tianyu Zhang, Feng Yang, Xinhui Huang, Da Zhang, Xianliang Wang","doi":"10.1002/acm2.70793","DOIUrl":"10.1002/acm2.70793","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Proton arc therapy (PAT) is an emerging delivery modality that delivers proton beams through continuous gantry rotation combined with spot scanning. Compared with intensity-modulated proton therapy (IMPT), PAT improves target conformity and spares organs at risk. However, the dynamic multi-angle irradiation pattern may alter the low-dose region distribution: the low-dose bath expands while the integral dose decreases. The net effect on secondary cancer risk, especially in radiosensitive lungs, remains unclear. Quantitative risk assessment is essential for clinical translation of PAT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To quantitatively compare secondary lung cancer risk between PAT and IMPT using organ equivalent dose (OED) and lifetime attributable risk (LAR) models, and to assess cross-population robustness across China, France, Sweden, and Germany.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Data from 25 lung cancer patients (60 Gy/30 fractions) were retrospectively included. For each patient, robustly optimized IMPT and PAT plans were generated with a 3 mm setup and 3% range uncertainties across 21 error scenarios. Dosimetric parameters—ipsilateral lung <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>V</mi>\u0000 <mn>5</mn>\u0000 </msub>\u0000 <annotation>${{mathrm{V}}_5}$</annotation>\u0000 </semantics></math>, <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>V</mi>\u0000 <mn>20</mn>\u0000 </msub>\u0000 <annotation>${{mathrm{V}}_{20}}$</annotation>\u0000 </semantics></math>, and mean dose; whole lungs <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>V</mi>\u0000 <mn>5</mn>\u0000 </msub>\u0000 <annotation>${{mathrm{V}}_5}$</annotation>\u0000 </semantics></math>, <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>V</mi>\u0000 <mn>20</mn>\u0000 </msub>\u0000 <annotation>${{mathrm{V}}_{20}}$</annotation>\u0000 </semantics></math>, and mean dose; and esophageal mean dose—were compared between the two techniques. The mechanistic OED model (with repopulation factor R) and its simplified linear model were used to calculate OED for the ipsilateral lung, both l","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70793","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148919824","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":"AI-assisted software development for brachytherapy seed inventory management","authors":"Tonghe Wang,&nbsp;Joel Beaudry,&nbsp;Antonio L Damato,&nbsp;Marisa Kollmeier,&nbsp;David Aramburu Núñez","doi":"10.1002/acm2.70795","DOIUrl":"10.1002/acm2.70795","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Medical physics departments frequently rely on in-house software to address niche clinical needs, yet these tools are often built by physicists without formal software engineering training, resulting in legacy applications that are difficult to maintain, poorly documented, and vulnerable to obsolescence from operating system upgrades. This study investigates the use of AI-driven “vibe coding”, i.e. software development through natural language prompting, to enable a clinical physicist with no web development experience to replace an obsolete MATLAB-based radioactive seed inventory system with a modern desktop application.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and methods</h3>\u0000 \u0000 <p>Development was performed using Claude Code (Anthropic) powered by the Claude Sonnet 4.6 large language model. A structured “Plan-Review-Execute-Verify-Feedback” (PREVF) methodology governed all development, with the physicist providing natural language prompts and the AI generating all source code. The resulting application manages five seed models across four clinical applications, with features including seed batch lifecycle tracking, calibration record management, audit logging, waste deposit tracking, etc. Evaluation metrics included development time and prompt volume, feature completeness against eight pre-defined requirements, System Usability Scale (SUS) scores comparing the legacy and new systems, and an independent maintainability test in which team members with minimal coding experience attempted modifications without developer assistance.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The application was developed in approximately 13 hours, using approximately 115 natural language prompts. All eight functional requirements were fully implemented. The new application received a median SUS score of 95 compared to 32.5 for the legacy system. In the maintainability evaluation, three independent testers completed bug fixes and feature modifications in one to two prompts each, all in under 10 min, without guidance from the original developer.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>AI-driven vibe coding enables clinical medical physicists to rapidly develop and maintain operational software, resolving the maintenance bottleneck characteristic of legacy in-house tools. The PREVF methodology provides a structured framework for physicist oversight of AI-generated code. This approach has potential applicability to provide clinical support tools by medical physics departments.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556308/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148911923","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":"Routine physics work efficacy and efficiency improvement through a shared-duty physicist-of-the-day model in a multi-hospital radiation oncology network","authors":"Guang-Pei Chen,&nbsp;Douglas E. Prah,&nbsp;Eric S. Paulson","doi":"10.1002/acm2.70792","DOIUrl":"10.1002/acm2.70792","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Background&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Large multi-hospital radiation oncology networks often rely on site-exclusive physicist coverage models that can lead to imbalanced workload distribution, inconsistent task execution, communication fragmentation, and vulnerability to delayed or missed quality checks. Increasing clinical complexity and distributed staffing models necessitate operational strategies that improve efficiency, standardization, and safety across geographically separated sites.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;To describe the implementation of a shared-duty physicist-of-the-day (POD) model supported by a real-time operational dashboard and to evaluate its impact on workload distribution, task efficiency, and safety metrics across a multi-hospital radiation oncology network.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;A structural transition from a site-exclusive to a shared-duty POD model was implemented in our institution—a four-site academic radiation oncology system. A custom application, RadOncStatusBoard, was developed using structured query language (SQL)-based integration with the Mosaiq Record &amp; Verify system to aggregate real-time patient appointments, treatment progress, quality checklist (QCL) items, and weekly chart check (WCC) eligibility. Microsoft Teams channels were used for daily communication and task coordination. Operational data from two matched 21-month intervals—before and after POD restructuring—were extracted using SQL. Evaluated metrics included task volumes, claim times, completion times, WCC performance, billing accuracy, and dosimetry-related Radiation Oncology Incident Learning System (RO-ILS) event reporting. Right-skewed distributions were summarized using medians and interquartile ranges (IQR). Surveys of physicists and dosimetrists were performed to assess end-user perceptions of workflow and safety.&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;Workload balance improved across all task categories, with substantial decreases in main-to-satellite task ratios (e.g., the ratio for chart close decreased from 1.91 to 1.27). Task claim and completion times decreased markedly at both main and satellite locations (e.g., chart-close claim time decreased from 36.8 to 6.2 min at the main campus). WCC completion improved from 97.7% to 99.9%, and WCC charge capture increased from 96.1% to 99.4%. The proportion of dosimetry-related RO-ILS events decreased numerically from 31.0% to 26.7% (&lt;i&gt;p&lt;/i&gt; = 0.339). Survey responses from physicists and dosimetrists indicated improved workflow clarity, com","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556306/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148911914","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":"Reducing the dose delivered to major intracranial blood vessels in brain radiotherapy using spot-scanning proton arc therapy","authors":"Peilin Liu,&nbsp;Sebastian Tattenberg,&nbsp;Xiaoda Cong,&nbsp;Peter Y. Chen,&nbsp;Xuanfeng Ding,&nbsp;Abdelkhalek Hammi","doi":"10.1002/acm2.70780","DOIUrl":"10.1002/acm2.70780","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Background&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Glioblastoma (GBM) patients have poor clinical prognoses, which may partially be explainable by correlations between radiation-induced killing of circulating blood cells (CBCs) and worse clinical outcomes. Proton radiotherapy is currently delivered via intensity-modulated proton therapy (IMPT), for which the target is irradiated from a few different angles. Spot-scanning proton arc therapy (SPArc), for which the target is irradiated from arc trajectories, is associated with dosimetric benefits, and the first SPArc treatments of head-and-neck cancer patients have now been reported. However, since SPArc increases the low-dose bath, concerns have been raised about potentially higher killing of CBC.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;This study aims to evaluate and compare blood vessel dose and dose-averaged linear energy transfer (LET&lt;sub&gt;d&lt;/sub&gt;) distributions between IMPT and SPArc, with and without blood vessel sparing, in patients with GBM.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;For 10 GBM patients, patient-specific cerebrovasculature models were developed, and IMPT and SPArc treatment plans were created according to current clinical standards (IMPT&lt;sub&gt;Conv&lt;/sub&gt; and SPArc&lt;sub&gt;Conv&lt;/sub&gt;) and with sparing of delineated blood vessels (IMPT&lt;sub&gt;Sparing&lt;/sub&gt; and SPArc&lt;sub&gt;Sparing&lt;/sub&gt;) for every patient. Dose and LET&lt;sub&gt;d&lt;/sub&gt; distributions were then compared across all treatment plans.&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;While treatment plans maintained comparable target coverage, blood vessel sparing significantly reduced the mean dose to delineated blood vessels, with values of 6.5 ± 2.9 Gy(RBE) for IMPT&lt;sub&gt;Conv&lt;/sub&gt;, 5.3 ± 2.3 Gy(RBE) for IMPT&lt;sub&gt;Sparing&lt;/sub&gt;, 5.6 ± 2.2 Gy(RBE) for SPArc&lt;sub&gt;Conv&lt;/sub&gt;, and 3.8 ± 1.6 Gy(RBE) for SPArc&lt;sub&gt;Sparing&lt;/sub&gt;. The dose within the 10% of blood vessel volume receiving the highest dose (D&lt;sub&gt;10%&lt;/sub&gt;) was 29.5 ± 13.4 Gy(RBE) for IMPT&lt;sub&gt;Conv&lt;/sub&gt;, 23.2 ± 11.0 Gy(RBE) for IMPT&lt;sub&gt;Sparing&lt;/sub&gt;, 24.5 ± 12.6 Gy(RBE) for SPArc&lt;sub&gt;Conv&lt;/sub&gt;, and 13.4 ± 8.7 Gy(RBE) for SPArc&lt;sub&gt;Sparing&lt;/sub&gt;.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Conclusions&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Implementation of blood vessel sparing resulted in successful reductions in blood vessel dose metrics while preserving target coverage, and SPArc further reduced blood vessel dose metrics compared with IMPT, with the potential to reduce radiation-induced lymphopenia and improve clinical outc","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/acm2.70780","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148919807","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 Cherenkov-excited fluorescence emission dosimetry for HDR Co-60 brachytherapy: Calibration and planar validation against TPS","authors":"Yagiz Yedekci,&nbsp;Mehmet Fazıl Enkavi,&nbsp;Ferah Yildiz","doi":"10.1002/acm2.70785","DOIUrl":"10.1002/acm2.70785","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Background&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Accurate dose verification in High-Dose-Rate (HDR) brachytherapy presents a significant challenge due to steep dose gradients and the absence of beam collimation. Conventional quality assurance (QA) methods typically rely on point detectors or film-based techniques, which lack the capability to provide real-time, full-field visualization of dose distributions in a water-equivalent medium. While Cherenkov emission (CE) imaging has been investigated for Iridium-192 (&lt;sup&gt;192&lt;/sup&gt;Ir) systems, the low mean photon energy of &lt;sup&gt;192&lt;/sup&gt;Ir (∼380 keV) constrains the optical yield and limits the signal-to-noise ratio. Because Cobalt-60 (&lt;sup&gt;60&lt;/sup&gt;Co) emits higher primary photon energies, it generates distinct Cherenkov intensities and spatial characteristics, requiring dedicated evaluation.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;This study aims to characterize the relationship between Cherenkov emission intensity and absorbed dose generated by an HDR &lt;sup&gt;60&lt;/sup&gt;Co source. Furthermore, it seeks to generate high-resolution two-dimensional dose maps using Cherenkov-excited fluorescence imaging and validate their dosimetric accuracy against Treatment Planning System (TPS) calculations to evaluate the system for clinical QA implementation.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;A custom 3D-printed polylactic acid (PLA) phantom was fabricated with an internal cavity filled with an aqueous quinine hemisulfate solution (1 g/L). This solution was used to convert ultraviolet Cherenkov photons into isotropic visible fluorescence, thereby enhancing optical signal detection. Optical emissions were captured using a standard monochrome CMOS camera positioned at a 24 cm working distance. To eliminate radiation-induced artifacts on the sensor without relying on complex time-gated hardware, an image processing pipeline comprising dark frame subtraction, median filtering, and morphological operations was applied. A calibration function was established by delivering doses between 10 and 1500 cGy using a &lt;sup&gt;60&lt;/sup&gt;Co HDR afterloader. Dosimetric accuracy was then evaluated across ten independent verification plans using two-dimensional gamma index analysis with 3% dose difference and 3 mm distance-to-agreement (3%/3 mm) criteria.&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;The dosimetric calibration demonstrated a highly predictable and linear dose-response relationship, yielding a coefficient of determination (&lt;i&gt;R&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt;) of 0.9999 and a root mean square error (RMSE) of 3.46 cGy. For the clinical veri","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13556302/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148911950","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 inter-fractional anatomical variations due to compression belt placement reproducibility using MR-guided radiotherapy treatment fraction images","authors":"Olivia Shay,&nbsp;David Solis,&nbsp;Morgan Aire,&nbsp;Christopher Schneider,&nbsp;Krystal Kirby","doi":"10.1002/acm2.70783","DOIUrl":"10.1002/acm2.70783","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Background&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Abdominal compression (AC) using a belt-based system is widely employed in radiation therapy to limit respiration-induced target motion for abdominal and hepatic malignancies. While AC has demonstrated efficacy in reducing intrafraction motion amplitude, the interfractional anatomical consequences of daily compression belt (CB) placement variability remain poorly characterized. A clearer understanding of this variability is necessary to determine whether online adaptive radiotherapy (oART) is required to maintain dosimetric robustness throughout the treatment course.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;This study aims to quantify interfractional anatomical variability associated with CB use in a clinical MR-guided radiotherapy cohort and to compare these findings against a matched cohort of non-compressed abdominal patients to determine the clinical significance of CB-induced setup variability.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Daily treatment MR images were retrospectively collected from 17 CB patients and 17 matched non-CB controls treated on an MR-Linac. External contours were delineated at the center of the planning target volume (PTV) and at the region of maximum compression for CB patients. Interfractional variability was assessed using cross-sectional area (CSA), Dice Similarity Coefficient (DSC), Mean Distance to Agreement (MDA), and Hausdorff Distance (HD). Interfractional organ displacement of the liver and kidneys was quantified via rigid registration. Linear mixed-effects models (LMEMs) evaluated the association between patient demographics—including age, BMI, sex, subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT)—and interfractional variability metrics.&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;Interfractional DSC over the PTV region was significantly lower in the CB cohort compared with non-CB controls (&lt;i&gt;p&lt;/i&gt; = 0.01 and &lt;i&gt;p&lt;/i&gt; = 0.03 for comparisons to fraction one and sequential fraction comparisons, respectively), and MDA was significantly elevated in the CB cohort (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). No significant difference in CSA variability was observed between cohorts. In the maximum compression region, median HD was 1.6 cm relative to fraction one, with no significant correlation between compression-region and PTV-region CSA variability (&lt;i&gt;p&lt;/i&gt; = 0.99). Older age, male sex, and higher BMI were associated with improved belt-contact shape reproducibility (all &lt;i&gt;p&lt;/i&gt; &lt; 0.05), though these demographic effects did not translate to PTV-region stability. ","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13540267/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148887588","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 combined radiomics-clinical nomogram for assessing MRI-defined femoral Head collapse status in osteonecrosis of the femoral Head","authors":"Lijun Peng,&nbsp;Yi Zhou,&nbsp;Lihua Zhou","doi":"10.1002/acm2.70779","DOIUrl":"10.1002/acm2.70779","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Osteonecrosis of the femoral head (ONFH) frequently progresses to femoral head collapse, resulting in irreversible joint dysfunction and the need for total hip arthroplasty. Reliable assessment of magnetic resonance imaging (MRI)-defined collapse status remains limited with conventional assessment methods.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To develop and validate a multi-modal nomogram integrating MRI-based radiomics signatures and clinical risk factors for the assessment of MRI-defined collapse status in patients with osteonecrosis of the femoral head (ONFH).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This retrospective study analyzed 149 ONFH patients (99 non-collapsed, 50 collapsed), partitioned into training (<i>n</i> = 104) and testing (<i>n</i> = 45) sets. Radiomics features were extracted from MRI-based necrotic lesion segmentations. A Radscore, derived via least absolute shrinkage and selection operator (LASSO) regression, was integrated with selected clinical variables to construct a combined nomogram.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The combined clinical-radiomics model demonstrated favorable discriminative performance, achieving an AUC of 0.940 (95% CI: 0.858–0.994) in the testing set, which outperformed the clinical-only model (AUC = 0.589) and the radiomics-only model (AUC = 0.818). Using the cutoff determined by the Youden index in the training cohort, the combined model exhibited a sensitivity of 80.0%, specificity of 90.0%, and overall accuracy of 86.7% in the testing cohort. Calibration curves showed acceptable agreement between model-predicted probabilities and observed MRI-defined collapse status.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The integrated clinical-radiomics nomogram showed promising performance for non-invasive assessment of femoral head collapse status in patients with ONFH. This quantitative approach may assist individualized collapse-status stratification, but external validation and prospective clinical workflow studies are required before routine clinical implementation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13535668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148873998","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":"Empirical noise mapping guides optimal region-of-interest selection for accurate noise estimation in prostate DWI","authors":"Milica Medved,&nbsp;Aritrick Chatterjee,&nbsp;Ambereen Yousuf,&nbsp;Batuhan Gundogdu,&nbsp;Aytekin Oto,&nbsp;Gregory S. Karczmar","doi":"10.1002/acm2.70738","DOIUrl":"10.1002/acm2.70738","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Background&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Signal-to-noise ratio (SNR) measurements are important for quality assurance, especially when quantitative MRI markers or new hardware are being developed or evaluated. Regions of low signal or assumed uniform signal are used for SNR estimation in a variety of MR image types, but this is unreliable due to spatial heterogeneity of noise arising from the organization of multiple-detector arrays and sensitivity encoding (SENSE) reconstruction.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;We present a universally applicable method for empirical noise mapping by propagating simulated noise through the image-generating reconstruction pipeline, to identify optimal regions of interest (ROIs) for determining noise levels in prostate diffusion-weighted imaging (DWI).&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Thirty-six men were imaged at 3T with DWI. K-space data were propagated through an off-line reconstruction pipeline including sensitivity encoding (SENSE), to generate DW images. Simulated complex Gaussian noise generated from prescan per-channel measurements was similarly processed to produce pure noise maps. Per-voxel standard deviations (SD) of spatial distributions of noise, averaged over prostate, internal obturator muscle (IOM), low signal (anterior and posterior), rectum, and bladder ROIs were calculated and compared to evaluate suitability for SNR estimation in prostate DWI.&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;IOM ROI noise levels, averaged bilaterally, were not significantly different from those in the prostate. Bladder ROI noise levels were comparable. Noise levels measured in low signal areas were highly dependent on SENSE algorithm regularization strength.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Discussion&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;The proposed method can be used—on any scanner—to accurately calculate noise levels in MR images, without repeated acquisition or interference from SENSE use.&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;Bladder and averaged IOM ROIs are appropriate for estimating DWI noise levels in the prostate. Low signal ROIs should not be used, due to the strong dependence on the SENSE regularization strength, and by extension, on the SENSE reconstruction algorithm. The presented method can be used instead to obtain accurate spatial maps of noise levels.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 ","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":"27 9","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13535670/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148874105","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}