Publications by authors named "Yuka Urago"
Article Synopsis
- - The study analyzed 10 years of treatment planning error data collected by medical physicists, focusing on high-risk errors, the impact of treatment volume on error rates, and the effectiveness of an Automated Plan Checking System (APCS).
- - Findings indicated that using APCS reduced error rates by around 1% for high-risk errors and 3% for low-risk errors, and there was an inverse relationship between the number of treatments and error rates.
- - The research also revealed that high workloads among medical physicists and a higher number of less experienced physicians were linked to increased error occurrences, emphasizing the need for adequate training and additional plan checkers to mitigate these errors.
Article Synopsis
- - This study investigates how the movement of the liver during breathing affects the accuracy of stereotactic body radiation therapy (SBRT) for patients with spine metastasis, particularly looking at treatment plans for patients with liver lesions.
- - Researchers analyzed treatment plans for 15 patients using CT scans taken during both inhalation and exhalation to assess how liver motion impacted radiation dosage delivered to the spine and surrounding tissues.
- - Their findings suggest that without incorporating strategies like beam avoidance, the liver's movement can result in significant radiation dose discrepancies, especially affecting the spinal cord, highlighting the need for careful evaluation of respiratory management during treatment.
Article Synopsis
- * A study evaluated a new method for visualizing 3D dose distributions using panoramic reconstruction computed tomography images in four head and neck cancer patients, achieving a high correlation in dose metrics.
- * The method aids dentists by providing clear visualizations of radiation doses that can lead to complications, improving the management of dental care for these patients.
Accelerator-based boron neutron capture therapy (BNCT) systems employing a solid-state lithium target indicated the reduction of neutron flux over the lifetime of a target, and its reduction could represent the neutron flux model. This study proposes a novel compensatory approach for delivering the required neutron fluence and validates its clinical applicability. The proposed approach relies on the neutron flux model and the cumulative sum of real-time measurements of proton charges.
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- A study was conducted to compare the effectiveness of two types of spacers, hyaluronic acid (HA) and hydrogel spacer (HS), in reducing rectal toxicity during prostate cancer radiotherapy.
- The study involved 38 patients, with HS and HA impacting different doses of radiation to the rectum, demonstrating that HA provided a significantly lower dose compared to HS.
- The findings suggest that HA not only reduces rectal radiation exposure more effectively but also has better spatial expansion capabilities, indicating its potential as a preferred option over HS.
. In current dosimetry protocols, the estimated uncertainty of the measured absorbed dose to waterin carbon-ion beams is approximately 3%. This large uncertainty is mainly contributed by the standard uncertainty of the beam quality correction factor.
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- - This study aimed to evaluate the relative biological effectiveness (RBE) of an epithermal neutron beam contaminated with fast neutrons in a boron neutron capture therapy (BNCT) system, conducted at the National Cancer Center Hospital in Tokyo, Japan.
- - Various human cell lines (SAS, SCCVII, U87-MG, and NB1RGB) were used to calculate the neutron beam's RBE, with results showing that the neutron beam had lower doses for 10% cell survival compared to X-ray irradiation, indicating a different biological impact.
- - The calculated RBE values for the different cell lines were 1.7, 2.2, 1.3, and 2.
Article Synopsis
- The study focuses on improving the setup process of lung shields (LS) used in total body irradiation (TBI) by evaluating a new mobile imaging system (TBI-MI) that offers real-time monitoring.
- Evaluations included measuring displacement accuracy, image quality, and the system's ability to detect patient movement during the procedure, with the TBI-MI proving effective and reliable.
- Results indicated that the TBI-MI can provide acceptable image quality while enhancing patient safety through better monitoring capabilities during TBI treatments.
Article Synopsis
- Boron Neutron Capture Therapy (BNCT) is gaining traction in cancer treatment due to advancements in accelerator-based systems, but detailed processes for these systems are still lacking.
- * The study aims to assess potential risks associated with implementing accelerator-based BNCT systems through a detailed failure mode and effects analysis (FMEA) involving a diverse medical team.
- * A total of 165 failure modes were identified, with 30 classified as high risk and 17 as very high risk, highlighting the importance of education and training for staff as the number of BNCT facilities grows.*
This study aimed to clarify the differences in radiotherapy dose characteristics and delivery efficiency between the supine and prone positions in patients with prostate cancer using the CyberKnife. The planning computed tomography (CT) and delineations of the prone position were obtained by rotating the supine CT images with delineations of 180° using image processing software. The optimization parameters for planning target volume (PTV) and organs at risk (OARs) were based on the prone position.
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- This study aimed to evaluate the accuracy of a brachytherapy source's movement using a high-speed camera to track its position and measure dwell time and transit dose.
- A custom jig was used, with the camera recording the high-speed movements of the source, while treatment plans incorporated various dwell times and measurements to compare against nominal values.
- Results showed that measured source positions differed by ≤1 mm, with slight variances in dwell times and significant differences in transit dose contributions based on movement, demonstrating the effectiveness of using high-speed imaging for dose assessments in brachytherapy.
Article Synopsis
- Contour delineation in radiation oncology is essential but often inaccurate due to inconsistencies between different observers; the study explored automated segmentation methods using atlases and AI to enhance accuracy and efficiency for Organs at Risk in cancer patients.
- The study involved 21 prostate cancer patients and 30 head and neck cancer patients, evaluating segmentation accuracy using tools like MIM Maestro and MIM Contour ProtégéAI, measuring performance through similarity indices and visual assessments by radiation oncologists.
- Results indicated that the AI-based model outperformed atlas-based methods for prostate cancer, especially in bladder and rectum delineation; however, both models showed similar accuracy for head and neck cancers, with AI segmentation offering significant time savings