A5041359509- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Medical Imaging Techniques and Applications
- Brain Metastases and Treatment
- Radiation Detection and Scintillator Technologies
- Computational Geometry and Mesh Generation
- Glioma Diagnosis and Treatment
- Nuclear Physics and Applications
- Effects of Radiation Exposure
- 3D Shape Modeling and Analysis
- Radiation Dose and Imaging
- Cleft Lip and Palate Research
- Lung Cancer Research Studies
- Radiomics and Machine Learning in Medical Imaging
- Head and Neck Cancer Studies
- Hepatocellular Carcinoma Treatment and Prognosis
- Digital Image Processing Techniques
- Advanced X-ray and CT Imaging
- Nuclear reactor physics and engineering
- Advances in Oncology and Radiotherapy
- Body Composition Measurement Techniques
- Cancer Genomics and Diagnostics
- Chemical Synthesis and Characterization
- Veterinary Orthopedics and Neurology
- Congenital Ear and Nasal Anomalies
Niigata University Medical and Dental Hospital
2018-2024
Osaka University
2018-2023
Niigata University
1985-2022
Tokyo Institute of Technology
1995-2021
Yamaguchi University
2012
Toyota Technological Institute
2001
Abstract In conventional stereotactic radiosurgery (SRS), treatment of multiple brain metastases using isocenters is time‐consuming resulting in long dose delivery times for patients. A single‐isocenter technique has been developed which enables the simultaneous irradiation targets at one isocenter. This requires accurate positioning patient to ensure optimal coverage. We evaluated effect six degrees freedom (6DoF) setup errors setups on SRS distributions a technique. used simulated...
Purpose We sought to develop machine learning models detect multileaf collimator (MLC) modeling errors with the use of radiomic features fluence maps measured in patient‐specific quality assurance (QA) for intensity‐modulated radiation therapy (IMRT) an electric portal imaging device (EPID). Methods Fluence EPID 38 beams from 19 clinical IMRT plans were assessed. Plans various degrees error MLC parameters [i.e., transmission factor (TF) and dosimetric leaf gap (DLG)] positional comparison...
Objectives: The purpose of this study was to evaluate the optimal upper threshold levels a number individuals and determine most suitable threshold. Methods: A phantom model ten patients were used in study. made acrylic resin urethane had nine pillar-shaped air spaces. subjects female with jaw deformities who not affected by respiratory disease. determined using "calculation CT value disparities" (CCTD) technique, which we devised. In other words, mean values along two lines (air space soft...
Flattening filter–free (FFF) photon beams minimize the intrafraction motion of tumors, and this feature is useful in pulmonary malignancies, such as non-small-cell lung cancer (NSCLC). However, radiobiological effects on NSCLC cells, which are often treated with stereotactic body radiotherapy (SBRT), have not been investigated sufficiently. Although cell motility may be promoted by a low dose, relationship between dose rate has evaluated. The purpose study was to evaluate FFF survival NSCLC....
The effect of dose-delivery time with flattening filter (FF) and filter-free (FFF) photon beams based on microdosimetric kinetic model (MKM) was investigated in this study. Monte Carlo simulation the particle heavy ion transport code system (PHITS) performed to calculate dose-mean lineal energy yD (keV/μm) FF FFF 6 MV using IAEA phase-space files Varian TrueBeam linear accelerator. Human non-small cell lung cancer NCI-H460 cells were used determine MKM parameters under condition that times...
To evaluate the biological effectiveness of dose associated with interruption time; and propose compensation method based on when an occurs during photon radiation therapy.The lineal energy distribution for human salivary gland tumor was calculated by Monte Carlo simulation using a beam. The (Dbio) estimated microdosimetric kinetic model. compensating factor physical difference Dbio without (Δ) derived. time (τ) varied to 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 75, 120...
The purpose of this study was to create and evaluate deep learning-based models detect classify errors multi-leaf collimator (MLC) modeling parameters in volumetric modulated radiation therapy (VMAT), namely the transmission factor (TF) dosimetric leaf gap (DLG).A total 33 clinical VMAT plans for prostate head-and-neck cancer were used, assuming a cylindrical homogeneous phantom, error created by altering original value TF DLG ± 10, 20, 30% treatment planning system (TPS). Gaussian filters...
Abstract Purpose We sought to develop machine learning models predict the results of patient‐specific quality assurance (QA) for volumetric modulated arc therapy (VMAT), which were represented by several dose‐evaluation metrics—including gamma passing rates (GPRs)—and criteria based on radiomic features 3D dose distribution in a phantom. Methods A total 4,250 cylindrical dummy phantom 140 arcs from 106 clinical VMAT plans extracted. obtained following metrics: GPRs with global and local...
Inorganic polyphosphate is a linear polymer containing tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. Polyphosphate has been recognized as potent anti-metastasis reagent. However, the molecular mechanism underlying action on cancer cells poorly understood. In this study, we investigated involvement in radio-sensitivity using human non–small cell lung line, H1299. We found that treatment decreases cellular adenosine triphosphate levels, suggesting...
Abstract Purpose We calculated the dosimetric indices and estimated tumor control probability (TCP) considering six degree‐of‐freedom (6DoF) patient setup errors in stereotactic radiosurgery (SRS) using a single‐isocenter technique. Methods used simulated spherical gross volumes (GTVs) with diameters of 1.0 cm (GTV 1), 2.0 2), 3.0 3), distance ( d ) between target center isocenter was set to 0, 5, 10 cm. created dose distribution by convolving blur component uniform distribution. The...
The High-Intensity Proton Accelerator Project, named J-PARC, is in progress, with the aim of enabling studies on latest basic science and advancement nuclear technology. In project, a high-energy proton accelerator complex world's highest instantaneous intensity under construction. order to establish reasonable shielding design, both simplified detailed design methods were used J-PARC. This paper reviews present status radiation safety study for
Neutron capture cross-section measurements for 237Np have been conducted with the Accurate Nucleus Reaction Measurement Instrument (ANNRI) at Materials and Life Science Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC) using neutrons energy ranging from thermal to 1 MeV. A time-of-flight (TOF) method a NaI(Tl) detector was employed data were analyzed based on pulse-height weighting technique in order derive neutron cross-section. The absolute determined first resonance...
(1) Background: The impacts of metal artifacts (MAs) on the contouring workload for head and neck radiotherapy have not yet been clarified. Therefore, this study evaluated relationship between time MAs area treatment planning. (2) Methods: We used planning computed tomography (CT) images radiotherapy. were classified into three severities by percentage CT containing MAs: mild (<25%), moderate (25−75%), severe (>75%). randomly selected nine patients to evaluate area. (3) Results: showed...
We proposed a new mathematical model that combines an ordinary differential equation (ODE) and microdosimetric kinetic (MKM) to predict the tumor-cell lethal effect of Stereotactic body radiation therapy (SBRT) applied non-small cell lung cancer (NSCLC). The tumor growth volume was calculated by ODE in multi-component (MCM) for lines NSCLC A549 NCI-H460 (H460). prescription doses 48 Gy/4 fr 54 Gy/3 were used SBRT, SBRT on cells evaluated MKM. also effects (1) linear quadratic (LQM) MKM, (2)...
To evaluate the effect of interruption in radiotherapy due to machine failure patients and medical institutions using risk analysis (MFRA).The during treatment is assigned three scores (biological effect, B; occurrence, O; cost labor repair parts, C) for each type failure. The biological patient (BPR) economic institution (EIR) are calculated as product B O ( B×O ) C C×O ), respectively. MFRA performed two linear accelerators (linacs).The multileaf collimator (MLC) fault has highest BPR...
Objectives: We evaluated the radiobiological effectiveness based on yields of DNA double-strand breaks (DSBs) field induction with flattening filter (FF) and FF-free (FFF) photon beams. Methods: used particle heavy ion transport system (PHITS) a water equivalent phantom (30 × 30 cm 3 ) to calculate physical qualities dose-mean lineal energy (y D 6 MV FF FFF. The relative biological DNA-DSBs (RBE DSB was calculated for standard radiation such as 220 kVp X-rays by using estimating SSBs DSBs....
This study investigated the efficacy and safety of radiotherapy as part multidisciplinary therapy for advanced hepatocellular carcinoma (HCC). Clinical data 49 HCC patients treated with were assessed retrospectively. The was by progression-free survival, disease control rate, overall survival. Safety symptoms hematological assay, changes in hepatic reserve function determined Child–Pugh score albumin–bilirubin (ALBI) score. Forty underwent curative radiotherapy, nine portal vein tumor...
Abstract Purpose The interruption time is the irradiation that occurs at sites and operations such as gantry, collimator, couch rotation, patient setup within field in radiotherapy. However, radiobiological effect of prolonging treatment by for tumor cells little evaluated. We investigated on effectiveness with photon beams based a modified microdosimetric kinetic (mMK) model. Methods dose‐mean lineal energy y D (keV/µm) 6‐MV was calculated particle heavy ion transport system (PHITS). set...