Publications by authors named "Akira Tsuzuki"

The increase in high-precision radiation therapy, particularly volumetric-modulated arc therapy (VMAT), has increased patient numbers and expanded treatment sites. However, a significant challenge in VMAT treatment planning is the inconsistent plan quality among different planners and facilities. This study explored the use of dose-volume histogram (DVH) prediction tools to address these disparities, specifically focusing on RapidPlan (Varian Medical Systems) and PlanIQ (Sun Nuclear).

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Background: The quality of treatment planning for stage III non-small cell lung cancer varies within and between facilities due to the different professions involved in planning. Dose estimation parameters were calculated using a feasibility dose-volume histogram (FDVH) implemented in the treatment planning quality assurance software PlanIQ. This study aimed to evaluate differences in treatment planning between occupations using manual FDVH-referenced treatment planning to identify their characteristics.

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Background: In this study, we investigated subjective geriatric complaints (SGCs) as conditions regarding health concerns in community-dwelling older people and analyzed their frequencies with aging and relationships with other factors.

Methods: This cross-sectional study enrolled 10,434 older people living in a community with a representative aging population in Japan. A questionnaire was sent by mail to those who had not applied for formal care needs certification.

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Purpose: The purpose of this study was to assess the quality of treatment planning using the PlanIQ software and to investigate whether it is possible to improve the quality of treatment planning using the "Feasibility dose-volume histogram (DVH) " implemented in the PlanIQ software.

Methods: Using the PlanIQ software, we retrospectively analyzed the learning curve regarding the quality of the treatment plans for 148 patients of prostate intensity-modulated radiation therapy and volumetric-modulated radiation therapy performed at our institution over the past eight years. We also sought to examine the possibility of improving treatment planning quality by re-planning in 47 patients where the quality of the target dose and the dose limits for organs at risk (OARs) were inadequate.

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Purpose: During treatment planning for head-and-neck volumetric-modulated arc therapy (VMAT), manual contouring of the metal artifact area of artificial teeth is done, and the area is replaced with water computed tomography (CT) values for dose calculation. This contouring of the metal artifact areas, which is performed manually, is subject to human variability. The purpose of this study is to evaluate and analyze the effect of inter-observer variation on dose distribution.

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Background/aim: In this study, we investigated the effect of rectal gas on the dose distribution of prostate cancer using a volumetric modulated arc therapy (VMAT) treatment planning.

Materials And Methods: The first is the original structure set, clinical target volume (CTV), the rectum, and the bladder used clinically. The second is a structure set (simulated gas structure set) in which the overlapping part of the rectum and PTV is overwritten with Hounsfield Unit -950 as gas.

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Methods to evaluate the positional reproducibility of breath-hold irradiation mostly require manual operation. The purpose of this study is to propose a method to determine the reproducibility of breath-hold irradiation of lung tumors between fractions using non-artificial methods. This study included 13 patients who underwent terminal exhaled breath-hold irradiation for primary and metastatic lung cancer.

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Aim: Subjective memory complaints (SMC) have attracted attention in recent years in relation to the early stages of dementia. However, it is not clear whether SMC are related to social and leisure activities. The aim of this study was to evaluate SMC in relation to activities in community-dwelling older adults.

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We initiated the Robotic Smart Home (RSH) project to develop a comfortable, safe home environment for all people, including the elderly and individuals with disabilities. An important consideration when introducing robots into a home environment is the confined living space, the so-called space problem. The RSH project plans to simultaneously develop robots and an architectural design for living spaces to create an optimal home environment that will help elderly people live independently at home for longer periods.

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We previously developed a new enzyme-targeting radiosensitization treatment named Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II), which contains hydrogen peroxide and sodium hyaluronate for injection into various types of tumors. For breast cancer treatment, the radiosensitization agent was injected into the tumor tissue twice a week under ultrasonographic guidance, immediately prior to each administration of radiation therapy. At approximately three hours after the second or third injection, computed tomography (CT) was performed to confirm the production and distribution of oxygen gas generated from the KORTUC radiosensitization agent by catalysis of peroxidases contained mainly in tumor tissue.

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We recently developed Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas (KORTUC) as a strategy to increase intratumoral oxygen concentrations and degrade antioxidant enzymes such as peroxidase and catalase. We then developed KORTUC II, which uses sodium hyaluronate containing hydrogen peroxide as a radiosensitizer. KORTUC II requires twice-weekly administration to sustain its effects, but decreasing the frequency of radiosensitizer injections to once-weekly would reduce the burden on the patients and the physicians.

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Background: We have developed a new radiosensitization treatment called Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II). Using KORTUC II, we performed breast-conserving treatment (BCT) without any surgical procedure for elderly patients with breast cancer in stages I/II or patients refusing surgery. Since surgery was not performed, histological confirmation of the primary tumor region following KORTUC II treatment was not possible.

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We introduced non-surgical therapy with a novel enzyme-targeting radiosensitization treatment, Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II) into early stages breast cancer treatment. The purpose of this study was to examine changes in tumor shadows and microcalcifications on mammography (MMG) following KORTUC II for elderly patients with breast cancer. We also sought to determine whether MMG was useful in evaluating the therapeutic effect of KORTUC II.

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