Nihon Hoshasen Gijutsu Gakkai zasshi最新文献_第6页

[8. Commissioning of 1.5 T MR Linac "Elekta Unity"]. (8。1.5 T MR直线发电机“Elekta Unity”的调试。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0505

Masato Tsuneda

引用次数: 0

[Evaluation of the Accuracy of Patent Fixation System Using a Bi-directional X-ray Image Matching System during Spine Stereotactic Body Radiation Therapy]. [利用双向x线图像匹配系统评估脊柱立体定向放射治疗中专利固定系统的准确性]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1533

Kenji Matsumoto, Takahiro Sakamoto, Masakazu Otsuka, Hiroyuki Kosaka, Hidekazu Nambu

{"title":"[Evaluation of the Accuracy of Patent Fixation System Using a Bi-directional X-ray Image Matching System during Spine Stereotactic Body Radiation Therapy].","authors":"Kenji Matsumoto, Takahiro Sakamoto, Masakazu Otsuka, Hiroyuki Kosaka, Hidekazu Nambu","doi":"10.6009/jjrt.25-1533","DOIUrl":"https://doi.org/10.6009/jjrt.25-1533","url":null,"abstract":"Purpose: To evaluate the accuracy of fixation devices during irradiation of our thoracic and lumbar vertebral stereotactic body radiation therapy (SBRT) and to suggest appropriate planning target volume margins.Methods: Nine patients (45 sessions) with spinal metastases treated with spinal SBRT were studied. A fixation system with a torso shell was used as a fixture for thoracic and lumbar spinal lesions. In the patient setup, radiographic imaging was performed using Exactrac (Brainlab, Munich, Germany), followed by cone beam computed tomography (CBCT) confirmation to ensure that the images were matched within 0.3 mm just before irradiation. Irradiation was started after the collation, and additional X-ray imaging using Exactrac was performed immediately before, during, and immediately after treatment, respectively, to evaluate the fixation accuracy during irradiation.Results: The mean ±1 standard deviation for each direction for movement during irradiation with the body shell was as follows: Lateral direction: 0.01±0.21 mm, head-tail direction: -0.01±0.18 mm, anteroposterior direction: 0.06±0.16 mm, roll: 0.02±0.19°, pitch: -0.02±0.29°, yaw: -0.03±0.23°.Conclusion: The image guided radiotherapy system using X-ray imaging with Exactrac allowed the evaluation of positioning accuracy during irradiation. The body shell fixation system was able to ensure fixation accuracy within 1 mm during irradiation. In addition, the positioning during irradiation using Exactrac is very useful in the evaluation of positioning accuracy during irradiation in SBRT of the vertebral body, where very high irradiation accuracy is required.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144201022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Reduction of Lens Absorbed Dose through Optimization of the X-ray Tube Position during Localizer Radiograph in Radiation Therapy Planning CT]. [通过优化x射线管在放疗计划CT定位时的位置来降低晶状体吸收剂量]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1565

Kenji Kanemoto, Minoru Nakao, Kiyoshi Yamada

{"title":"[Reduction of Lens Absorbed Dose through Optimization of the X-ray Tube Position during Localizer Radiograph in Radiation Therapy Planning CT].","authors":"Kenji Kanemoto, Minoru Nakao, Kiyoshi Yamada","doi":"10.6009/jjrt.25-1565","DOIUrl":"https://doi.org/10.6009/jjrt.25-1565","url":null,"abstract":"Purpose: The International Commission on Radiological Protection Publication 118 reduced the threshold dose for cataract formation to 0.5 Gy and requires dose optimization in computed tomography (CT) for radiation therapy planning. This study investigated the operational characteristics of the CT automatic exposure control (CT-AEC) system using a carbon fiber couch top and head immobilization devices, as well as the X-ray tube position during the localizer radiograph orientation (hereafter referred to as the localizer orientation). It also influenced the lens absorbed dose and reduced the lens absorbed dose through optimization of the localizer orientation.Methods: Measured the image noise and the lens absorbed dose based on the localizer orientation. The reference localizer orientation was set to the right-lateral to left-lateral (RL) orientation, and the image quality setting value (noise index: NI) of the CT-AEC was set to 6, which corresponds to the predefined threshold.Results: The average standard deviation in the anterior-posterior (AP) orientation was 4.1±0.1, which was larger than the 3.9±0.1 for the RL orientation (P<0.05). The absorbed dose to the lens absorbed dose was 68.5±1.7 mGy for the AP orientation and 73.3±2.3 mGy for the reference RL orientation, representing an 8% reduction (P<0.01).Conclusion: This study suggests that imaging in the AP orientation potentially reduces the lens absorbed dose.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144509867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Usefulness of Deep Learning Reconstruction in Low-dose Lung Cancer CT Screening Protocols]. [深度学习重建在低剂量肺癌CT筛查方案中的应用]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1485

Yuse Shono, Masaaki Fukunaga, Hiroyuki Yamamoto, Osamu Ito

{"title":"[Usefulness of Deep Learning Reconstruction in Low-dose Lung Cancer CT Screening Protocols].","authors":"Yuse Shono, Masaaki Fukunaga, Hiroyuki Yamamoto, Osamu Ito","doi":"10.6009/jjrt.25-1485","DOIUrl":"https://doi.org/10.6009/jjrt.25-1485","url":null,"abstract":"Purpose: This study aimed to evaluate the changes in physical characteristics when the image reconstruction method, radiation dose, and pitch factor (PF) were varied in low-dose lung cancer CT screening, and to determine the optimal radiation dose and PF for appropriate dose reduction and the usefulness of deep learning reconstruction (DLR).Methods: Physical characteristics were evaluated using an Aquilion PrimeSP/i Edition (Canon Medical Systems, Tochigi) X-ray CT unit in conjunction with water phantoms and a chest phantom. Image reconstruction methods included filtered back projection (FBP), iterative reconstruction (IR), and DLR. Exposure conditions were varied across four dose levels and three PF levels. Physical characteristics were quantitatively evaluated using the noise power spectrum, task transfer function (TTF), low-contrast object-specific contrast-to-noise ratio (CNRLO), and system performance function (SPF).Results: Both the IR application method and DLR improved noise characteristics compared to FBP, even at low doses, and reduced noise in the high spatial frequency domain when the PF level was lowered. DLR improved TTF at low doses and SPF at a standard deviation (SD) of 50. There was no significant difference in CNRLO by PF level.Conclusion: DLR may be useful in low-dose lung cancer CT screening, and appropriate SD settings and PF selection may contribute to image optimization.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144251196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Safety Management in Radiological Medical Equipment: Looking Back and Moving Forward]. [放射医疗设备安全管理：回顾与前进]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0606

引用次数: 0

[4. Chubu Branch, Kinki Branch, Chugoku-Shikoku Branch, Kyushu Branch]. (4。中部分行，近畿分行，中部四国分行，九州分行]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0104

Naoki Nagasawa, Shigeyoshi Saito, Rie Ishii, Yasumasa Saigo

引用次数: 0

[Thinking about 10 Years from Now]. [从现在开始考虑10年]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0204

Satoshi Yanagita

引用次数: 0

[Connecting to the Future of the Society]. [连接社会的未来]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0500

Kazuya Ohashi

引用次数: 0

[Participation/Dispatch Reports on ECR 2025]. [ECR 2025的参与/派遣报告]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0507

Nobuyuki Akiyama

引用次数: 0

[Evaluation of Low-contrast Detectability of Different Reconstruction Algorithms and Noise Reduction Intensities in the Upper Abdominal Pseudo-human Phantom]. [不同重建算法和降噪强度对上腹部伪人幻像低对比度可检测性的评价]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1507

Haruna Hatakeyama, Yoshitaka Ota, Akio Tamura

{"title":"[Evaluation of Low-contrast Detectability of Different Reconstruction Algorithms and Noise Reduction Intensities in the Upper Abdominal Pseudo-human Phantom].","authors":"Haruna Hatakeyama, Yoshitaka Ota, Akio Tamura","doi":"10.6009/jjrt.25-1507","DOIUrl":"https://doi.org/10.6009/jjrt.25-1507","url":null,"abstract":"Purpose: The effects of reconstruction algorithm and noise reduction intensity on low-contrast detectability in abdominal CT examinations were investigated.Methods: FBP, hybrid IR, and deep learning-based reconstruction methods (DLR for body, DLR for body sharp) were compared using an upper abdominal pseudo-human phantom. Imaging was performed under four radiation dose conditions, with three noise reduction intensities, and NPS and CNRLO were used as evaluation indices.Results: DLR for body sharp showed excellent low-contrast detection performance with strong noise reduction and achieved a higher CNRLO than the others. Hybrid IR and DLR for body showed equivalent performance regardless of noise reduction intensity, confirming the limitations of low-frequency noise suppression.Conclusion: It is important to select a reconstruction algorithm and noise reduction intensity according to the purpose of the examination, and DLR for body sharp is useful for improving image quality and reducing exposure at low doses.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144303898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0