Journal of Applied Clinical Medical Physics最新文献

{"title":"Effects of simultaneous multislice acceleration on the stability of radiomics features in parametric maps of IVIM and DKI in uterine cervical cancer.","authors":"Shuangquan Ai, Wei Peng, Rong Hou, Huiting Zhang, Robert Grimm, Zilong Yuan, Yulin Liu","doi":"10.1002/acm2.70063","DOIUrl":"https://doi.org/10.1002/acm2.70063","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this study was to investigate the influence of the simultaneous multislice acceleration (SMS) technique as well as two-dimensional (2D) and three-dimensional (3D) tumor segmentations on radiomics features (RFs) within the parametric maps of cervical cancer, which were computed by intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI). Additionally, the study sought to identify those RFs that could characterize the clinical stages (low-stage vs. high-stage) of cervical cancer.</p><p><strong>Materials and methods: </strong>Multi-b-value diffusion-weighted imaging (DWI) of 40 patients with cervical cancer were collected using the SMS technique with acceleration factors (AF) of 1-3. RFs were extracted from parametric maps representing pure diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (f), mean diffusivity (MD), and mean kurtosis (MK). A total of 93 2D and 93 3D RFs were extracted from per parametric map. The concordance correlation coefficient (CCC) and coefficients of variation (COV) were used to jointly assess the stability of features. Finally, the intra-class correlation coefficient (ICC) was used for intra-group consistency assessment. Receiver operating characteristic (ROC) curve was used to evaluate diagnostic performance of stable features in distinguishing lower and higher stages.</p><p><strong>Results: </strong>Feature stability decreased with higher AF. Among these features, 9.1% of 2D and 12.7% of 3D RFs were stable (CCC > 0.9 and COV ≤ 0.1). ADC maps had the highest stability, whileas D^* and f maps had the lowest stability and 3D features were more stable than 2D features. A total of 5 2D and 25 3D stable features were identified that could distinguish lower and higher stages (AUC = 0.66-0.83).</p><p><strong>Conclusion: </strong>SMS demonstrated impact on the stability of RFs in IVIM and DKI parametric maps, particularly for D* and f maps. Multi-b-value DWI with SMS (AF = 2) was recommended for clinical radiomics research.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70063"},"PeriodicalIF":2.0,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating auto-contouring accuracy in reduced CT dose images for radiopharmaceutical therapies: Denoising and evaluation of ¹⁷⁷Lu DOTATATE therapy dataset.","authors":"Hung-Te Yang, Kuan-Yin Ko, Ching-Ching Yang","doi":"10.1002/acm2.70066","DOIUrl":"https://doi.org/10.1002/acm2.70066","url":null,"abstract":"<p><strong>Purpose: </strong>Reducing radiation dose attributed to computed tomography (CT) may compromise the accuracy of organ segmentation, an important step in ¹⁷⁷Lu DOTATATE therapy that affects both activity and mass estimates. This study aimed to facilitate CT dose reduction using deep learning methods for patients undergoing serial single photon emission computed tomography (SPECT)/CT imaging during ¹⁷⁷Lu DOTATATE therapy.</p><p><strong>Methods: </strong>The ¹⁷⁷Lu DOTATATE patient dataset hosted in Deep Blue Data was used in this study. The noise insertion method incorporating the effect of bowtie filter, automatic exposure control, and electronic noise was applied to simulate images at four reduced dose levels. Organ segmentation was carried out using the TotalSegmentator model, while image denoising was performed with the DenseNet model. The impact of segmentation performance on the dosimetry accuracy of ¹⁷⁷Lu DOTATATE therapy was quantified by calculating the percent difference between a dose rate map segmented with a reference mask and the same dose rate map segmented with a test mask (PD_dose) for spleen, right kidney, left kidney, and liver.</p><p><strong>Results: </strong>Before denoising, the mean ± standard deviation of PD_dose for all critical organs were 2.31 ± 2.94%, 4.86 ± 9.42%, 8.39 ± 14.76%, 12.95 ± 19.99% in CT images at dose levels down to 20%, 10%, 5%, 2.5% of the normal dose, respectively. After denoising, the corresponding results were 1.69 ± 2.25%, 2.84 ± 4.46%, 3.72 ± 4.22%, 7.98 ± 15.05% in CT images at dose levels down to 20%, 10%, 5%, 2.5% of the normal dose, respectively.</p><p><strong>Conclusion: </strong>As dose reduction increased, CT image segmentation gradually deteriorated, which in turn deteriorated the dosimetry accuracy of ¹⁷⁷Lu DOTATATE therapy. Improving CT image quality through denoising could enhance ¹⁷⁷Lu DOTATATE dosimetry, making it a valuable tool to support CT dose reduction for patients undergoing serial SPECT/CT imaging during treatment.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70066"},"PeriodicalIF":2.0,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Human papillomavirus (HPV) prediction for oropharyngeal cancer based on CT by using off-the-shelf features: A dual-dataset study.","authors":"Junhua Chen, Yanyan Cheng, Lijun Chen, Banghua Yang","doi":"10.1002/acm2.70061","DOIUrl":"https://doi.org/10.1002/acm2.70061","url":null,"abstract":"<p><strong>Background: </strong>This study aims to develop a novel predictive model for determining human papillomavirus (HPV) presence in oropharyngeal cancer using computed tomography (CT). Current image-based HPV prediction methods are hindered by high computational demands or suboptimal performance.</p><p><strong>Methods: </strong>To address these issues, we propose a methodology that employs a Siamese Neural Network architecture, integrating multi-modality off-the-shelf features-handcrafted features and 3D deep features-to enhance the representation of information. We assessed the incremental benefit of combining 3D deep features from various networks and introduced manufacturer normalization. Our method was also designed for computational efficiency, utilizing transfer learning and allowing for model execution on a single-CPU platform. A substantial dataset comprising 1453 valid samples was used as internal validation, a separate independent dataset for external validation.</p><p><strong>Results: </strong>Our proposed model achieved superior performance compared to other methods, with an average area under the receiver operating characteristic curve (AUC) of 0.791 [95% (confidence interval, CI), 0.781-0.809], an average recall of 0.827 [95% CI, 0.798-0.858], and an average accuracy of 0.741 [95% CI, 0.730-0.752], indicating promise for clinical application. In the external validation, proposed method attained an AUC of 0.581 [95% CI, 0.560-0.603] and same network architecture with pure deep features achieved an AUC of 0.700 [95% CI, 0.682-0.717]. An ablation study confirmed the effectiveness of incorporating manufacturer normalization and the synergistic effect of combining different feature sets.</p><p><strong>Conclusion: </strong>Overall, our proposed model not only outperforms existing counterparts for HPV status prediction but is also computationally accessible for use on a single-CPU platform, which reduces resource requirements and enhances clinical usability.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70061"},"PeriodicalIF":2.0,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving organ dose sparing in left-sided breast cancer with yaw-limited volumetric modulated arc therapy: A dosimetric comparison to conventional and intensity modulated radiation therapy approaches.","authors":"Gerhard Pollul, Sascha Grossmann, Heiko Karle, Tilman Bostel, Heinz Schmidberger","doi":"10.1002/acm2.70041","DOIUrl":"https://doi.org/10.1002/acm2.70041","url":null,"abstract":"<p><strong>Background: </strong>To assess the dose-sparing capabilities of a yaw-limited volumetric modulated arc therapy (YL_VMAT) beam setup for adjacent organs at risk (OAR) in comparison with 3D-conventional radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT) and conventional VMAT for radiation therapy in left-sided breast cancer patients.</p><p><strong>Methods: </strong>In total, 80 treatment plans for 20 patients, of which 10 patients underwent CT-scans in deep inspiration breath-hold (DIBH) and 10 patients in free-breathing (FB) technique. Besides generally tangential-weighted static and IMRT beams, VMAT treatment plans with approximately 270° arc length have been compared and analyzed to a multi-field, yaw-adapted, unconventional partial VMAT technique retrospectively. The prescription dose was set to 40.05 Gy in 15 fractions.</p><p><strong>Results: </strong>We achieved a more pronounced steeper dose falloff directed from the thoracic wall to the adjacent lung tissue resulting in a significantly better ipsilateral lung and considerably cardiac dose sparing using the YL_VMAT method in general. Compared with standard techniques (IMRT, VMAT, 3D-CRT), YL-VMAT in combination with DIBH can achieve lower mean doses for the heart (1.05 Gy vs. 1.73 Gy, 2.16 Gy and 1.44 Gy), the left anterior descending (LAD) artery (3.68 Gy vs. 6.53 Gy, 5.13 Gy and 8.64 Gy) and the left lung (3.59 Gy vs. 5.39 Gy, 4.79 Gy and 5.87 Gy), respectively. Also with FB, the corresponding mean doses for the left lung and cardiac structures were lower with the YL-VMAT method than with IMRT (heart: 1.70 Gy vs. 2.44 Gy; LAD: 6.50 Gy vs. 11.97 Gy; left lung: 3.10 Gy vs. 4.72 Gy), VMAT (heart: 1.70 Gy vs. 2.52 Gy; LAD: 6.50 Gy vs. 9.06 Gy; left lung: 3.10 Gy vs. 4.46 Gy) and 3D-CRT (heart: 1.70 Gy vs. 2.78 Gy; LAD: 6.50 Gy vs. 15.09 Gy; left lung: 3.10 Gy vs. 5.77 Gy). In addition, we found out superiority of YL_VMAT for the V5, V10, and V20 Gy to the left lung. For DIBH and FB, all differences for the left lung were significant, with p < 0.05.</p><p><strong>Conclusions: </strong>With the YL_VMAT technique, dose exposures to radiosensitive OARs like the lung, heart and LAD artery can be reduced considerably to very low values in comparison to already established planning methods. The benefits must be weighed against the potential risks induced by an increased dose exposure to the contralateral breast.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70041"},"PeriodicalIF":2.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143531446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of CT radiation beam width with a pencil ionization chamber and radiopaque mask.","authors":"Rani Al-Senan, David M Gauntt, Gary T Barnes","doi":"10.1002/acm2.70027","DOIUrl":"https://doi.org/10.1002/acm2.70027","url":null,"abstract":"<p><strong>Purpose: </strong>This study compares fan beam CT scanner radiation beam widths measured with a pencil ionization chamber-radiopaque mask technique with commonly used film and computed radiography (CR) measurements.</p><p><strong>Methods: </strong>For a given fan beam CT scanner x-ray beam, the ionization chamber-mask technique determines the radiation beam width by exposing a 100 mm pencil chamber with and without a radiopaque cylindrical mask of known width that is a fraction of the nominal beam width. Additional widths can then be measured using the same kV, mAs, and pre-patient filtration without the mask. CT scanner radiation beam width measurements with the technique were compared with film and CR techniques.</p><p><strong>Results: </strong>Measurements from 20 different detector configurations/focal spot combinations on fan beam CT scanners from two manufacturers are presented. The root mean square (RMS) difference between the ionization chamber-mask measured beam widths and film measurements was 0.31 mm, with a similar RMS difference of 0.28 mm with CR measurements. These results compare favorably with the RMS difference between film and CR measurements, which was 0.35 mm.</p><p><strong>Conclusion: </strong>This study demonstrates that radiation beam widths of fan beam CT scanners can be measured using the ionization chamber-radiopaque mask method with an RMS accuracy of better than 0.5 mm. We demonstrate the method is applicable to nominal beam widths ranging from 1 to 40 mm.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70027"},"PeriodicalIF":2.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143523416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of artificial intelligence in brachytherapy.","authors":"Jingchu Chen, Richard L J Qiu, Tonghe Wang, Shadab Momin, Xiaofeng Yang","doi":"10.1002/acm2.70034","DOIUrl":"10.1002/acm2.70034","url":null,"abstract":"<p><p>Artificial intelligence (AI) has the potential to revolutionize brachytherapy's clinical workflow. This review comprehensively examines the application of AI, focusing on machine learning and deep learning, in various aspects of brachytherapy. We analyze AI's role in making brachytherapy treatments more personalized, efficient, and effective. The applications are systematically categorized into seven categories: imaging, preplanning, treatment planning, applicator reconstruction, quality assurance, outcome prediction, and real-time monitoring. Each major category is further subdivided based on cancer type or specific tasks, with detailed summaries of models, data sizes, and results presented in corresponding tables. Additionally, we discuss the limitations, challenges, and ethical concerns of current AI applications, along with perspectives on future directions. This review offers insights into the current advancements, challenges, and the impact of AI on treatment paradigms, encouraging further research to expand its clinical utility.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70034"},"PeriodicalIF":2.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143515836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of a prototype rapid kilovoltage x-ray image guidance system designed for a linear accelerator radiation therapy unit.","authors":"Theodore Arsenault, Jonathan Arrue, Kenneth Gregg, Atallah Baydoun, Atefeh Rezai, Christian Langmack, Lauren Henke, Daniel E Spratt, Rojano Kashani, Alex Price","doi":"10.1002/acm2.70060","DOIUrl":"https://doi.org/10.1002/acm2.70060","url":null,"abstract":"<p><strong>Purpose: </strong>This study evaluates a novel cone-beam computed tomography (CBCT) imaging solution integrated onto a conventional C-arm linear accelerator (linac) with increased gantry speed. The purpose is to assess the impact of improved imaging hardware and reconstruction algorithms on image quality.</p><p><strong>Methods: </strong>Hypersight-CBCT (HS-CBCT) system was compared with the original system (OG-CBCT) on a TrueBeam linac. Performance tests included mechanical, geometric, setup accuracy, and image quality assessment. Image quality metrics were evaluated using conventional CBCT reconstruction and advanced iterative reconstruction (iCBCT), fast iCBCT, and iCBCT with metal artifact reduction. Dosimetry measurements were acquired.</p><p><strong>Results: </strong>The HS-CBCT system acquired images in 24.0-44.0s (half trajectory/full trajectory), faster than the OG-CBCT system's acquisition time of 33.5-60.5s (half trajectory/full trajectory). The HS-CBCT system's faster gantry speed resulted in comparable image quality to the OG-CBCT. It improved high-contrast resolution, modulation transfer function, and low-contrast visibility. The faster gantry speed also produced lower radiation doses. The system's uniformity and resolution also improved, particularly with full-fan acquisition techniques.</p><p><strong>Conclusion: </strong>The novel HS-CBCT system on a conventional C-arm linac exhibits superior imaging capabilities compared to the OG-CBCT. Faster gantry speed, larger imaging area, and advanced reconstruction algorithms contribute to enhanced image quality and reduced dose. The study provides comprehensive insights into the new system's performance, serving as a benchmark for future linac installations and highlighting potential benefits in clinical applications. Further investigations are suggested for 4D acquisitions and long-term machine performance.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70060"},"PeriodicalIF":2.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expert panel on monitoring radiation doses from recurrent medical diagnostic procedures: Sixth Gilbert W. Beebe Webinar.","authors":"Donald P Frush, Armin Ansari, James A Brink, Ourania Kosti, David B Larson, Martha S Linet, Mahadevappa Mahesh, Ioannis Sechopoulos, Jenia Vassileva","doi":"10.1002/acm2.70022","DOIUrl":"https://doi.org/10.1002/acm2.70022","url":null,"abstract":"<p><p>Recurrent imaging is an essential tool for patient care but with an attendant dose from radiation exposure. Recurrent imaging has been the subject of increasing scrutiny and debate based largely on the risk from increasing cumulative doses. However, the accountability for and actions with recurrent imaging as a special component in the general construct of radiation protection in medicine is unclear. This is demonstrated by the perspectives provided by the various imaging community experts. Some perspectives may be different, but many share a common ground. Understanding these various perspectives illustrates the wide-ranging optics in considering benefits and costs in the recurrent imaging paradigm and, moreover, the value in pursuing multi-stakeholder-derived harmonization for recurrent imaging and radiation dose. This move towards consensus would be to the benefit of the imaging community, referrers, and other related healthcare professionals, as well as patients, their caregivers, and the public.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70022"},"PeriodicalIF":2.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143515838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of bulk density assignment of bone on MRI-based abdominal region radiotherapy planning for MR-linac workflow.","authors":"Kota Abe, Masato Tsuneda, Yukio Fujita, Yukinao Abe, Takashi Uno","doi":"10.1002/acm2.70059","DOIUrl":"https://doi.org/10.1002/acm2.70059","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of the present study was to evaluate the impact of bone relative electron density (rED) assignment on radiotherapy planning for the abdominal region.</p><p><strong>Methods: </strong>Twenty patients who received abdominal radiotherapy using MR-Linac and underwent magnetic resonance imaging (MRI) and computed tomography (CT) simulation were analyzed. The reference plan (RP) was established using both CT and MR image sets (RP_CT and RP_MRI). The RP_MRI utilized the bulk density method. The recalculated RPs derived from various rED assignment methods were evaluated for comparison on both datasets. The RPs were recalculated by excluding rED assignment for bones (scenario A). Based on the International Commission on Radiation Units and Measurements report, lung contours were assigned rED of 0.258, and body contours were assigned 1.000 (scenario B) and 1.019 (scenario C). Dose volume histogram (DVH) differences between the three recalculated scenarios and RPs were evaluated. D95, D99, and D1cc were evaluated for target volumes, including gross tumor volume, internal target volume, and planning target volume. DVH parameters, including D1cc for each abdominal organ at risk (OAR) and the mean dose to the liver and kidneys, were evaluated. Three-dimensional local gamma analysis was conducted to assess dose distribution differences between the three recalculated scenarios and RPs.</p><p><strong>Results: </strong>In all scenarios of the CT- and MRI-based validation, the average gamma pass rates (2%/2 mm) were higher than 95%. In the CT-based validation, all target DVHs across the 20 patients showed that none exceeded 2% error in scenario A, whereas 2% and 14% exceeded the threshold in scenarios B and C, respectively. For OARs in CT and MRI-based validation, absolute maximum dose differences when compared with those of the RP were 0.19 Gy and 0.22 Gy, respectively, in scenario A.</p><p><strong>Conclusion: </strong>Excluding bone rED considerations in abdominal treatment planning may not yield notable clinical differences.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70059"},"PeriodicalIF":2.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143501460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of cardiac motion on dose distribution during stereotactic arrhythmia radioablation treatment: A simulation and phantom study.","authors":"Takayuki Miyachi, Takeshi Kamomae, Fumitaka Kawabata, Kuniyasu Okudaira, Mariko Kawamura, Shunichi Ishihara, Shinji Naganawa","doi":"10.1002/acm2.70021","DOIUrl":"https://doi.org/10.1002/acm2.70021","url":null,"abstract":"<p><strong>Purpose: </strong>Cardiac motion may degrade dose distribution during stereotactic arrhythmia radioablation using the CyberKnife system, a robotic radiosurgery system. This study evaluated the dose distribution changes using a self-made cardiac dynamic platform that mimics cardiac motion.</p><p><strong>Methods: </strong>The cardiac dynamic platform was operated with amplitudes of 5 and 3.5 mm along the superior-inferior (SI) and left-right (LR) directions, respectively. The respiratory motion tracking of the CyberKnife system was applied when respiratory motion, simulated using a commercial platform, was introduced. The accuracy of respiratory motion tracking was evaluated by the correlation error between infrared markers and a fiducial marker. The dose distribution was compared with and without cardiac motion. The evaluations included error in the centroid analysis of the irradiated dose distribution, dose profile analysis in the SI and LR directions, and dose distribution analysis comparing the irradiated and planned dose distributions.</p><p><strong>Results: </strong>Cardiac motion increased the correlation error in the direction of motion. Cardiac motion displaced the centroid by up to 0.23 and 0.19 mm in the SI and LR directions, respectively. Cardiac motion blurring caused the distance of the isodose lines to become smaller (bigger) at higher (lower) doses in the SI direction. The gamma pass rate was reduced by cardiac motion but exceeded 94.1% with 1 mm/3% for all conditions. Respiratory motion tracking was also effective under cardiac motion. The cardiac motion slightly varied the dose at the edges of the irradiation volume.</p><p><strong>Conclusion: </strong>While cardiac motion increased respiratory tracking correlation errors, its effects on dose distribution were limited in this study. Further studies using motion phantoms that are close to a human or individual patient are necessary for a more detailed understanding of the effects of cardiac motion.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70021"},"PeriodicalIF":2.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}