医療科学部
Profile Information
- Affiliation
- School of Medical Sciences, Fujita Health University
- Degree
- Doctor of Radiology(Jan, 2020, Gunma Prefectural College of Health Sciences)
- J-GLOBAL ID
- 202001016614192119
- researchmap Member ID
- R000001839
Research History
2-
Jan, 2025 - Present
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Apr, 2005 - Dec, 2024
Papers
85-
Journal of Radiation Research, Jan 15, 2025Abstract This study aimed to evaluate the recent trends in single-fraction conventional radiotherapy (CRT) as palliative treatment in Japan, using data from the National Database published by the Ministry of Health, Labor, and Welfare. Data from fiscal year (FY) 2014 to FY2022, specifically related to the utilization of single-fraction CRT, were analyzed. Multi-fraction CRT, stereotactic body radiotherapy (SBRT), intensity-modulated radiotherapy (IMRT), and brachytherapy were excluded. The primary outcome was the cumulative and annual number of single-fraction CRT courses. Additionally, quarterly course data from FY2019 to FY2022, the period for which monthly data were available, were assessed to evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on single-fraction CRT utilization. Of the total 2 315 607 radiotherapy courses, we identified 33 221 single-fraction CRT courses after excluding multi-fraction CRT (n = 1 835 650), SBRT (n = 33 935), IMRT (n = 332 827), and brachytherapy (n = 113 195). The annual number of single-fraction CRT courses increased from 1730 in FY2014 to 5642 in FY2022, with an average annual growth rate of 0.28 (range: −0.07 to 0.65). Outpatient courses significantly increased, particularly from FY2019 onward, surpassing inpatient courses in FY2022 (2914 vs 2728). The highest annual increase was observed in FY2020, particularly from April to December, although this upward trend did not persist in 2021. In conclusion, single-fraction CRT has exhibited a consistent upward trend, highlighting its expanding role in palliative radiotherapy. Although the COVID-19 pandemic temporarily accelerated this trend, its impact has already subsided, with growth rates returning to pre-pandemic levels.
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International Journal of Radiation Oncology*Biology*Physics, Dec, 2024PURPOSE: A novel classification system has been proposed to stratify patients undergoing palliative radiation therapy based on their pain response and time to progression. This study used prospective observational data to quantify quality of life (QoL) changes associated with pain response and the classification system. METHODS AND MATERIALS: Between August 2021 and September 2022, 366 painful lesions with a numerical rating scale of 2 or more from the 261 eligible patients underwent palliative radiation therapy. Patients were followed-up prospectively at 2, 4, 12, 24, 36, and 52 weeks postradiation therapy, with EORTC QLQ-C15-PAL and QLQ-BM22 questionnaires obtained simultaneously with pain response assessments. The primary endpoint was defined as the global health status/QoL improvements at 12 weeks based on minimally clinically important differences and compared by the pain response (responders vs. nonresponders) and by class 1 (no opioids, no reirradiation, n = 89), 2 (neither class 1 nor 3, n = 211), and 3 (opioids and reirradiation, n = 66). RESULTS: With a median follow-up time of 21 weeks for pain response and 13 weeks for QoL assessment, 1773 pairs of QLQ-C15-PAL and QLQ-BM22 questionnaires were collected. The QoL assessment at baseline was covered with 97% (355/366) of lesions and 67% (183/273) at 12 weeks: this compliance was lower in nonresponders than in responders (57% vs. 72%, P = .004) and highest in class 1, followed by classes 2 and 3 (70% vs. 44% vs. 39%, P = .001). The improvement rate was significantly different by class, with class 3 having the lowest in all subscales except nausea and psychosocial aspects: the improvement rate of global health status/QoL was 33% in class 1, 31% in class 2, and 20% in class 3, P = .001). CONCLUSIONS: The QoL changes associated with pain response and the classification system were identified, suggesting that the classification system may help identify populations more or less likely to improve QoL, in addition to separating pain response rates.
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Journal of applied clinical medical physics, 25(11) e14497, Nov, 2024PURPOSE: Total body irradiation before bone marrow transplantation for hematological malignancies using Radixact, a high-precision radiotherapy machine, can potentially reduce side effects and the risk of secondary malignancies. However, stable control of couch speed is critical, and direct assessment methods outlined in quality assurance guidelines are lacking. This study aims to develop a real-time couch speed verification system for the Radixact. METHODS: The developed system used a linear encoder to measure couch speed directly. Accuracy was verified via a linear stage, comparing measurements with a laser distance sensor. After placing a phantom simulating the human body on the Radixact couch, the couch speed was verified using predefined speed plans. RESULTS: Operating the linear stage at 0.1, 0.5, and 1.0 mm/s revealed that the maximum position error of the developed verification system compared to the laser distance sensor was nearly equivalent to the distance resolution of the system (0.05 mm/pulse), with negligible average speed error. When the Radixact couch operated at 0.1, 0.5, and 1.0 mm/s, the values obtained by the verification system agreed with the theoretical values within the sampling period (0.01 s) and distance resolution (0.05 mm). CONCLUSION: The verification system developed provides real-time monitoring of the speed of the Radixact table, ensuring treatment effectiveness and patient safety. It would guarantee the couch speed's soundness and contribute to the "visualization" of safety.
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Oral oncology, 157 106976-106976, Oct, 2024BACKGROUND AND PURPOSE: Hypothyroidism is a recognized late adverse event following radiotherapy for head and neck cancer (HNC). In the JCOG1008 trial, we treated patients with high-risk HNC with postoperative chemoradiotherapy. We aimed to elucidate factors associated with hypothyroidism by analyzing the JCOG1008 data. MATERIALS AND METHODS: In 2012-2018, 261 patients from 28 institutions were enrolled in JCOG1008. Thyroid function tests were conducted to assess hypothyroidism, including free thyroxine (FT4) and thyroid-stimulating hormone assays. Hypothyroidism was defined as Grade 2 or higher in CTCAE v4.0. Various clinical and dosimetric parameters were analyzed. In radiotherapy, there were no dose constraints for the thyroid. Multivariable analysis was conducted on these variables to identify predictive factors for hypothyroidism. RESULTS: The analysis included 162 patients (57 with 3D-CRT and 105 with IMRT), with a median follow-up of 4.7 years (0.3-9.3 years). Among these, 27 (16.7 %) developed hypothyroidism within 2 years after radiotherapy. In a multivariable analysis, the weekly cisplatin [OR=7.700 (CI: 1.632-36.343, p = 0.010)] and baseline FT4 [OR=0.009 (CI: <0.001-0.313, p = 0.010)] were significantly associated with hypothyroidism in the IMRT group. Regarding dosimetric characteristics, V60Gy [OR=1.069 (CI: 0.999-1.143, p = 0.054)] was potentially associated with the development of hypothyroidism. CONCLUSION: The study revealed that the incidence of hypothyroidism within 2 years after postoperative chemoradiotherapy for high-risk HNC was 16.7 % based on analytical results from prospective clinical trials.
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Cancers, 16(19), Sep 24, 2024Background/Objectives: Despite advancements in treatment for patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC), overall survival (OS) remains poor. The specific effects of varying heart and lung doses on OS in LA-NSCLC patients have not been thoroughly investigated, especially their combined impact on survival. This study aimed to examine the impact on OS of both individual and combined heart and lung doses in patients with LA-NSCLC treated with radiotherapy over a three-year follow-up period. Methods: A total of 120 patients who received definitive radiotherapy for LA-NSCLC (stage III, 92.5%) from January 2015 to January 2020 were retrospectively reviewed. The endpoint in this study was OS. Each patient was followed for a fixed period of three years. Results: Univariate Cox regression analysis showed that OS was significantly related to mean heart dose (MHD, hazard ratio [HR], 3.4 [1.8-6.3]; p < 0.001), pericardium V40 (HR, 3.2 [1.7-6.0]; p < 0.001), and total lung V20 (HR, 2.6 [1.4-5.0]; p = 0.003), and these were independent predictors for worse OS in multivariate analysis. Kaplan-Meier curve analysis with log-rank tests revealed that survival was significantly worse in patients with higher MHD (p < 0.001), pericardium V40 (p < 0.001), and total lung V20 (p = 0.002). Combining MHD and total lung V20, and pericardium V40 and total lung V20 provided enhanced risk stratification for OS (p < 0.001 for both combinations). Conclusions: The combination of heart and lung doses provided enhanced and more detailed risk stratification in prediction of OS for a fixed period of three years in LA-NSCLC patients treated with radiotherapy.
Misc.
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MEDICAL PHYSICS INTERNATIONAL, 4(2) 180, Dec, 2016 Peer-reviewed
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Japanese Journal of Clinical Radiology, 56(8) 935-942, Aug 10, 2011We presented our preliminary results of initial experience by Helical TomoTherapy held at the 23rd annual meeting of JASTRO on October 2010. In this analysis, 82 parotid glands from 41 patients, who were treated with definitive IMRT combined with or without systemic chemotherapy, were assessed for the correlation of radiation dose with parotid function evaluated by salivary scintigraphy. Acquired results of salivary scintigraphy are well correlated with grade of xerostomia after IMRT. Initial experience of IMRT in our institute for head and neck cancer is thought to be promising at the viewpoint of both clinical efficacy and less toxicity.
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Transactions of Japanese Society for Medical and Biological Engineering, 47(2) 215-221, Dec 1, 2009Salivary gland function is primarily evaluated by observing biopsy tissue and by measuring the saliva collected by gum test and saxon test. However, biopsy is an invasive method of evaluation for the salivary gland. In addition, neither the gum test nor the saxon test can specify the disordered parts, as saliva of the parotid or submandibular gland is difficult to separate from the collected saliva, meaning that function of the salivary gland other than overall saliva secretion cannot be adequately evaluated. As an imaging method, salivary scintigraphy is one method for evaluating function. However, radiation exposure is unavoidable with this modality, as radionuclides are used. Magnetic resonance imaging (MRI) is noninvasive and requires no exposure to radiation. In addition, this modality can obtain morphological, biochemical and physiological information with high spatial resolution for soft tissues using magnetism and electromagnetic waves. We examined the utility of equivalent cross-relaxation rate (ECR) imaging (ECRI) for functional evaluation of the parotid gland to detect minute changes in organization and molecular structure, offering information reflecting interactions with water molecules and biomacromolecules using MRI. A total of 15 patients with head-neck cancer underwent both salivary scintigraphy and MRI. ECR values were compared between non-and post-radiated parotid glands. In addition, ECR value was compared with maximum uptake rate (MUR), a functional parameter obtained by salivary gland scintigraphy. A correlation was detected between ECR values and MUR. Moreover, ECR values were significantly elevated in the post-radiated parotid gland. ECRI is thus useful for detecting changes in organization and molecular configuration and for evaluating function of the parotid gland after radiotherapy.
Books and Other Publications
1Research Projects
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2024 - Mar, 2027
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2021 - Mar, 2023