掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/s13246-023-01241-8

researchmap

その他リンク： https://link.springer.com/article/10.1007/s13246-023-01241-8/fulltext.html

掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/tomography9010009

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：British Institute of Radiology  

Objective:

We evaluated the radiobiological effect of the irradiation time with the interruption time of stereotactic radiosurgery (SRS) using CyberKnife^® (CK) systemfor brain metastases.

Methods:

We used the DICOM data and irradiation log file of the 10 patients with brain metastases from non–small-cell lung cancer (NSCLC) who underwent brain SRS. We defined the treatment time as the sum of the dose–delivery time and the interruption time during irradiations, and we used a microdosimetric kinetic model (MKM) to evaluate the radiobiological effects of the treatment time. The biological parameters, i.e. α₀, β₀, and the DNA repair constant rate (a + c), were acquired from NCI-H460 cell for the MKM. We calculated the radiobiological dose for the gross tumor volume (GTV_bio) to evaluate the treatment time’s effect compared with no treatment time as a reference. The D95 (%) and the Radiation Therapy Oncology Group conformity index (RCI) and Paddick conformity index (PCI) were calculated as dosimetric indices. We used several DNA repair constant rates (a + c) (0.46, 1.0, and 2.0) to assess the radiobiological effect by varying the DNA repair date (a + c) values.

Results:

The mean values of D95 (%), RCI, and PCI for GTV_bio were 98.8%, 0.90, and 0.80, respectively, and decreased with increasing treatment time. The mean values of D95 (%), RCI, and PCI of GTV_bio at 2.0 (a+c) value were 94.9%, 0.71, and 0.49, respectively.

Conclusion:

The radiobiological effect of the treatment time on tumors was accurately evaluated with brain SRS using CK.

Advances in knowledge:

There has been no published investigation of the radiobiological impact of the longer treatment time with multiple interruptions of SRS using a CK on the target dose distribution in a comparison with the use of a linac. Radiobiological dose assessment that takes into account treatment time in the physical dose in this study may allow more accurate dose assessment in SRS for metastatic brain tumors using CK.

DOI： 10.1259/bjro.20220013

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE INC  

Purpose: Patients with lung cancer and brain metastases represent a markedly heterogeneous population. Accurate prognosis is essential to optimally individualize care. In prior publications, we described the graded prognostic assessment (GPA), but a GPA for patients with small cell lung cancer (SCLC) has never been reported, and in non-small cell lung cancer (NSCLC), the effect of programmed death ligand 1 (PD-L1) was unknown. The 3-fold purpose of this work is to provide the initial report of an SCLC GPA, to evaluate the effect of PD-L1 on survival in patients with NSCLC, and to update the Lung GPA accordingly.Methods and Materials: A multivariable analysis of prognostic factors and treatments associated with survival was performed on 4183 patients with lung cancer (3002 adenocarcinoma, 611 nonadenocarcinoma, 570 SCLC) with newly diagnosed brain metastases between January 1, 2015, and December 31, 2020, using a multi-institutional retrospective database. Significant variables were used to update the Lung GPA.Results: Overall median survival for lung adenocarcinoma, SCLC, and nonadenocarcinoma was 17, 10, and 8 months, respectively, but varied widely by GPA from 2 to 52 months. In SCLC, the significant prognostic factors were age, performance status, extracranial metastases, and number of brain metastases. In NSCLC, the distribution of molecular markers among patients with lung adenocarcinoma and known primary tumor molecular status revealed alterations/expression in PD-L1 50% to 100%, PD-L1 1% to 49%, epidermal growth factor receptor, and anaplastic lymphoma kinase in 32%, 31%, 30%, and 7%, respectively. Median survival of patients with lung adenocarcinoma and brain metastases with 0, 1% to 49%, and >= 50% PD-L1 expression was 17, 19, and 24 months, respectively (P < .01), confirming PD-L1 is a prognostic factor. Previously identified prognostic factors for NSCLC (epidermal growth factor receptor and anaplastic lymphoma kinase status, performance status, age, number of brain metastases, and extracranial metastases) were reaffirmed. These factors were incorporated into the updated Lung GPA with robust separation between subgroups for all histologies.Conclusions: Survival for patients with lung cancer and brain metastases has improved but varies widely. The initial report of a GPA for SCLC is presented. For patients with NSCLC-adenocarcinoma and brain metastases, PD-L1 is a newly identified significant prognostic factor, and the previously identified factors were reaffirmed. The updated indices establish unique criteria for SCLC, NSCLC-nonadenocarcinoma, and NSCLC-adenocarcinoma (incorporating PD-L1). The updated Lung GPA, available for free at brainmetgpa.com, provides an accurate tool to estimate survival, individualize treatment, and stratify clinical trials. (C) 2022 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.ijrobp.2022.03.020

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER JAPAN KK  

This study aimed to evaluate the effect of target positioning error (TPE) on radiobiological parameters, such as tumor control probability (TCP) and normal tissue complication probability (NTCP), in stereotactic radiosurgery (SRS) for metastatic brain tumors of different sizes using CyberKnife. The reference SRS plans were created using the circular cone of the CyberKnife for each spherical gross tumor volume (GTV) with diameters (phi) of 5, 7.5, 10, 15, and 20 mm, contoured on computed tomography images of the head phantom. Subsequently, plans involving TPE were created by shifting the beam center by 0.1-2.0 mm in three dimensions relative to the reference plans using the same beam arrangements. Conformity index (CI), generalized equivalent uniform dose (gEUD)-based TCP, and NTCP of estimated brain necrosis were evaluated for each plan. When the gEUD parameter "a" was set to - 10, the CI and TCP for the reference plan at the phi 5-mm GTV were 0.90 and 80.8%, respectively. The corresponding values for plans involving TPE of 0.5-mm, 1.0-mm, and 2.0-mm were 0.62 and 77.4%, 0.40 and 62.9%, and 0.12 and 7.2%, respectively. In contrast, the NTCP for all GTVs were the same. The TCP for the plans involving a TPE of 2-mm was 7.2% and 68.8% at the phi 5-mm and phi 20-mm GTV, respectively. The TPEs corresponding to a TCP reduction rate of 3% at the phi 5-mm and phi 20-mm GTV were 0.41 and 0.99 mm, respectively. TPE had a significant effect on TCP in SRS for metastatic brain tumors using CyberKnife, particularly for small GTVs.

DOI： 10.1007/s12194-022-00655-5

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: We calculated the dosimetric indices and estimated the tumor control probability (TCP) considering six degree-of-freedom (6DoF) patient setup errors in stereotactic radiosurgery (SRS) using a single-isocenter technique. METHODS: We used simulated spherical gross tumor volumes (GTVs) with diameters of 1.0 cm (GTV 1), 2.0 cm (GTV 2), and 3.0 cm (GTV 3), and the distance (d) between the target center and isocenter was set to 0, 5, and 10 cm. We created the dose distribution by convolving the blur component to uniform dose distribution. The prescription dose was 20 Gy and the dose distribution was adjusted so that D95 (%) of each GTV was covered by 100% of the prescribed dose. The GTV was simultaneously rotated within 0°-1.0° (δR) around the x-, y-, and z-axes and then translated within 0-1.0 mm (δT) in the x-, y-, and z-axis directions. D95, conformity index (CI), and conformation number (CN) were evaluated by varying the distance from the isocenter. The TCP was estimated by translating the calculated dose distribution into a biological response. In addition, we derived the x-y-z coordinates with the smallest TCP reduction rate that minimize the sum of squares of the residuals as the optimal isocenter coordinates using the relationship between 6DoF setup error, distance from isocenter, and GTV size. RESULTS: D95, CI, and CN were decreased with increasing isocenter distance, decreasing GTV size, and increasing setup error. TCP of GTVs without 6DoF setup error was estimated to be 77.0%. TCP were 25.8% (GTV 1), 35.0% (GTV 2), and 53.0% (GTV 3) with (d, δT, δR) = (10 cm, 1.0 mm, 1.0°). The TCP was 52.3% (GTV 1), 54.9% (GTV 2), and 66.1% (GTV 3) with (d, δT, δR) = (10 cm, 1.0 mm, 1.0°) at the optimal isocenter position. CONCLUSION: The TCP in SRS for multiple brain metastases with a single-isocenter technique may decrease with increasing isocenter distance and decreasing GTV size when the 6DoF setup errors are exceeded (1.0 mm, 1.0°). Additionally, it might be possible to better maintain TCP for GTVs with 6DoF setup errors by using the optimal isocenter position.

DOI： 10.1002/acm2.13322

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We aimed to compare the outcomes of high-dose-rate brachytherapy (HDR-BT) boost and external beam radiation therapy (EBRT) alone for high-risk prostate cancer. This was a single-center, retrospective and observational study. Consecutive patients who underwent initial radical treatment by HDR-BT boost or EBRT alone from June 2009 to May 2016 at the Niigata University Medical and Dental Hospital, Japan were included. A total of 96 patients underwent HDR-BT boost, and 61 underwent EBRT alone. The prescription dose of HDR-BT boost was set to 18 Gy twice a day with EBRT 39 Gy/13 fractions. The dose for EBRT alone was mostly 70 Gy/28 fractions. The high-risk group received >6 months of prior androgen deprivation therapy. Overall survival, biochemical-free survival, local control and distant metastasis-free survival rates at 5 years were analyzed. The incidence of urological and gastrointestinal late adverse events of Grade 2 and above was also summarized. In the National Comprehensive Cancer Network (NCCN) high-risk calssification, HDR-BT boost had a significantly higher biochemical-free survival rate at 5 years (98.9% versus 90.7%, P = 0.04). Urethral strictures were more common in the HDR-BT boost group. We will continuously observe the progress of the study patients and determine the longer term results.

DOI： 10.1093/jrr/rrab006

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: We sought to develop machine learning models to detect multileaf collimator (MLC) modeling errors with the use of radiomic features of fluence maps measured in patient-specific quality assurance (QA) for intensity-modulated radiation therapy (IMRT) with an electric portal imaging device (EPID). METHODS: Fluence maps measured with EPID for 38 beams from 19 clinical IMRT plans were assessed. Plans with various degrees of error in MLC modeling parameters [i.e., MLC transmission factor (TF) and dosimetric leaf gap (DLG)] and plans with an MLC positional error for comparison were created. For a total of 152 error plans for each type of error, we calculated fluence difference maps for each beam by subtracting the calculated maps from the measured maps. A total of 837 radiomic features were extracted from each fluence difference map, and we determined the number of features used for the training dataset in the machine learning models by using random forest regression. Machine learning models using the five typical algorithms [decision tree, k-nearest neighbor (kNN), support vector machine (SVM), logistic regression, and random forest] for binary classification between the error-free plan and the plan with the corresponding error for each type of error were developed. We used part of the total dataset to perform fourfold cross-validation to tune the models, and we used the remaining test dataset to evaluate the performance of the developed models. A gamma analysis was also performed between the measured and calculated fluence maps with the criteria of 3%/2 and 2%/2 mm for all of the types of error. RESULTS: The radiomic features and its optimal number were similar for the models for the TF and the DLG error detection, which was different from the MLC positional error. The highest sensitivity was obtained as 0.913 for the TF error with SVM and logistic regression, 0.978 for the DLG error with kNN and SVM, and 1.000 for the MLC positional error with kNN, SVM, and random forest. The highest specificity was obtained as 1.000 for the TF error with a decision tree, SVM, and logistic regression, 1.000 for the DLG error with a decision tree, logistic regression, and random forest, and 0.909 for the MLC positional error with a decision tree and logistic regression. The gamma analysis showed the poorest performance in which sensitivities were 0.737 for the TF error and the DLG error and 0.882 for the MLC positional error for 3%/2 mm. The addition of another type of error to fluence maps significantly reduced the sensitivity for the TF and the DLG error, whereas no effect was observed for the MLC positional error detection. CONCLUSIONS: Compared to the conventional gamma analysis, the radiomics-based machine learning models showed higher sensitivity and specificity in detecting a single type of the MLC modeling error and the MLC positional error. Although the developed models need further improvement for detecting multiple types of error, radiomics-based IMRT QA was shown to be a promising approach for detecting the MLC modeling error.

DOI： 10.1002/mp.14699

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER JAPAN KK  

Through geometrical simulation, we evaluated the effect of rotational error in patient setup on geometrical coverage and calculated the maximum distance between the isocenter and target, where the clinical PTV margin secures geometrical coverage with a single-isocenter technique. We used simulated spherical GTVs with diameters of 1.0 (GTV 1), 1.5 (GTV 2), 2.0 (GTV 3), and 3.0 cm (GTV 4). The location of the target center was set such that the distance between the target and isocenter ranged from 0 to 15 cm. We created geometrical coverage vectors so that each target was entirely covered by 100% of the prescribed dose. The vectors of the target positions were simultaneously rotated within a range of 0 degrees-2.0 degrees around the x-, y-, and z-axes. For each rotational error, the reduction in geometrical coverage of the targets was calculated and compared with that obtained for a rotational error of 0 degrees. The tolerance value of the geometrical coverage reduction was defined as 5% of the GTV. The maximum distance that satisfied the 5% tolerance value for different values of rotational error at a clinical PTV margin of 0.1 cm was calculated. When the rotational errors were 0.5 degrees for a 0.1 cm PTV margin, the maximum distances were as follows: GTV 1: 7.6 cm; GTV 2: 10.9 cm; GTV 3: 14.3 cm; and GTV 4: 21.4 cm. It might be advisable to exclude targets that are > 7.6 cm away from the isocenter with a single-isocenter technique to satisfy the tolerance value for all GTVs.

DOI： 10.1007/s12194-020-00602-2

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1259/bjro.20200072

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: The interruption time is the irradiation interruption that occurs at sites and operations such as the gantry, collimator, couch rotation, and patient setup within the field in radiotherapy. However, the radiobiological effect of prolonging the treatment time by the interruption time for tumor cells is little evaluated. We investigated the effect of the interruption time on the radiobiological effectiveness with photon beams based on a modified microdosimetric kinetic (mMK) model. METHODS: The dose-mean lineal energy yD (keV/µm) of 6-MV photon beams was calculated by the particle and heavy ion transport system (PHITS). We set the absorbed dose to 2 or 8 Gy, and the interruption time (τ) was set to 1, 3, 5, 10, 30, and 60 min. The biological parameters such as α0, β0, and DNA repair constant rate (a + c) values were acquired from a human non-small-cell lung cancer cell line (NCI-H460) for the mMK model. We used two-field and four-field irradiation with a constant dose rate (3 Gy/min); the photon beams were paused for interruption time τ. We calculated the relative biological effectiveness (RBE) to evaluate the interruption time's effect compared with no interrupted as a reference. RESULTS: The yD of 6-MV photon beams was 2.32 (keV/µm), and there was little effect by changing the water depth (standard deviation was 0.01). The RBE with four-field irradiation for 8 Gy was decreased to 0.997, 0.975, 0.900, and 0.836 τ = 1, 10, 30, 60 min, respectively. In addition, the RBE was affected by the repair constant rate (a + c) value, the greater the decrease in RBE with the longer the interruption time when the (a + c) value was large. CONCLUSION: The ~10-min interruption of 6-MV photon beams did not significantly impact the radiobiological effectiveness, since the RBE decrease was <3%. Nevertheless, the RBE's effect on tumor cells was decreased about 30% by increasing the 60 min interruption time at 8 Gy with four-field irradiation. It is thus necessary to make the interruption time as short as possible.

DOI： 10.1002/acm2.13110

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

In conventional stereotactic radiosurgery (SRS), treatment of multiple brain metastases using multiple isocenters is time-consuming resulting in long dose delivery times for patients. A single-isocenter technique has been developed which enables the simultaneous irradiation of multiple targets at one isocenter. This technique requires accurate positioning of the patient to ensure optimal dose coverage. We evaluated the effect of six degrees of freedom (6DoF) setup errors in patient setups on SRS dose distributions for multiple brain metastases using a single-isocenter technique. We used simulated spherical gross tumor volumes (GTVs) with diameters ranging from 1.0 to 3.0 cm. The distance from the isocenter to the target's center was varied from 0 to 15 cm. We created dose distributions so that each target was entirely covered by 100% of the prescribed dose. The target's position vectors were rotated from 0°-2.0° and translated from 0-1.0 mm with respect to the three axes in space. The reduction in dose coverage for the targets for each setup error was calculated and compared with zero setup error. The calculated margins for the GTV necessary to satisfy the tolerance values for loss of GTV coverage of 3% to 10% were defined as coverage-based margins. In addition, the maximum isocenter to target distance for different 6DoF setup errors was calculated to satisfy the tolerance values. The dose coverage reduction and coverage-based margins increased as the target diameter decreased, and the distance and 6DoF setup error increased. An increase in setup error when a single-isocenter technique is used may increase the risk of missing the tumor; this risk increases with increasing distance from the isocenter and decreasing tumor size.

DOI： 10.1002/acm2.13081

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study investigated the efficacy and safety of radiotherapy as part of multidisciplinary therapy for advanced hepatocellular carcinoma (HCC). Clinical data of 49 HCC patients treated with radiotherapy were assessed retrospectively. The efficacy of radiotherapy was assessed by progression-free survival, disease control rate, and overall survival. Safety was assessed by symptoms and hematological assay, and changes in hepatic reserve function were determined by Child-Pugh score and albumin-bilirubin (ALBI) score. Forty patients underwent curative radiotherapy, and nine patients with portal vein tumor thrombus (PVTT) underwent palliative radiotherapy as part of multidisciplinary therapy. Local disease control for curative therapy was 80.0% and stereotactic body radiotherapy was 86.7% which was greater than that of conventional radiotherapy (60.0%). Patients with PVTT had a median observation period of 651 days and 75% three-year survival when treated with multitherapy, including radiotherapy for palliative intent, transcatheter arterial chemoembolization, and administration of molecular targeted agents. No adverse events higher than grade 3 and no changes in the Child-Pugh score and ALBI score were seen. Radiotherapy is safe and effective for HCC treatment and can be a part of multidisciplinary therapy.

DOI： 10.3390/cancers12102955

PubMed

researchmap

担当区分：責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier {BV}  

DOI： 10.1016/j.ejmp.2020.04.007

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: We sought to construct the optimal neurocognitive function (NCF) change criteria sensitive to health-related quality of life (HR-QOL) in patients who have undergone whole-brain radiation therapy (WBRT) for brain metastasis. METHODS: We categorized the patients by the changes of NCF into groups of improvement versus deterioration if at least one domain showed changes that exceeded the cut-off while other domains remained stable. The remaining patients were categorized as stable, and the patients who showed both significant improvement and deterioration were categorized as 'both.' We examined the clinical meaning of NCF changes using the cut-off values 1.0, 1.5, and 2.0 SD based on the percentage of patients whose HR-QOL changes were ≥ 10 points. RESULTS: Baseline, 4-month and 8-month data were available in 78, 41 (compliance; 85%), and 29 (81%) patients, respectively. At 4 months, improvement/stable/deterioration/both was seen in 15%/12%/41%/32% of the patients when 1.0 SD was used; 19%/22%/37%/22% with 1.5 SD, and 17%/37%/37%/9% with 2.0 SD. The HR-QOL scores on the QLQ-C30 functional scale were significantly worse in the deterioration group versus the others with 1.0 SD (p = 0.013) and 1.5 SD (p = 0.015). With 1.5 SD, the HR-QOL scores on the QLQ-BN20 was significantly better in the improvement group versus the others (p = 0.033). However, when 'both' was included in 'improvement' or 'deterioration,' no significant difference in HR-QOL was detected. CONCLUSIONS: The NCF cut-off of 1.5 SD and the exclusion of 'both' patients from the 'deterioration' and 'improvement' groups best reflects HR-QOL changes.

DOI： 10.1186/s12885-020-6559-3

PubMed

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier {BV}  

DOI： 10.1016/j.ctro.2019.10.006

researchmap

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/acm2.12603

PubMed

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

DOI： 10.1093/jrr/rry106

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.prro.2019.02.001

PubMed

researchmap

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/acm2.12467

PubMed

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ctro.2017.12.003

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

To investigate the effects of a respiratory gating and multifield technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer.
Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multifield technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans.
In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V-5Gy, V-20Gy, mean dose with all three plans and the Heart V-25Gy-V-40Gy with Gating-2-field plan, V-35Gy, V-40Gy, mean dose with No Gating-4-field plan and V-30Gy-V-40Gy, and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan.
The lung parameters were reduced by the respiratory gating technique and increased by the multifield technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications.

DOI： 10.1007/s11604-016-0606-7

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OXFORD UNIV PRESS  

The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au-Ag- Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm(3) of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 x 10 cm(2) using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 110 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of &gt;= 5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of &gt;= 4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose.

DOI： 10.1093/jrr/rrw092

Web of Science

PubMed

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Purpose: We evaluated the relationship between dosimetric parameters (DPs) and the incidence of radiation pneumonitis (RP) and investigated the feasibility of a proposed treatment planning technique with the potential of reducing RP in esophageal cancer patients treated with definitive chemoradiotherapy using extended fields. Patients and Methods: A total of 149 patients with locally advanced esophageal cancer were prospectively enrolled for extended-field radiotherapy (EFRT) to three-field regional lymphatics between September 2004 and June 2009. We retrospectively reviewed 86 consecutive patients who were treated with a total dose of 50.4 Gy ( plus an optional 9 Gy boost) and were available for dose-volume analysis. Lung DPs of patients in the Grade 0 1 RP (RPG≤1) group and the Grade 2 5 RP (RPG≥2) group were compared. We compared the proposed plan with the conventional plan to 50.4 Gy on DPs for each case. Results: Of these 86 patients, 10 (12%) developed RPG≥2 (Grade 2, n = 2 patients
Grade 3, n = 3
Grade 4, n = 3
Grade 5, n = 2). The patients in the RPG≤1 group showed significantly lower (P &lt
0.05) V5 and V10 values for the whole lung compared with those in the RPG≥2 group. There were two advantages gained from the proposed plan for V5 (&lt
55%) and V10 (&lt
37%) values and the conformity of the PTV. Conclusion: The increase in the volume of the lung exposed to low doses of EFRT was found to be associated with the incidence of RP. Our proposed plan is likely to reduce the incidence of RP. © The Author 2013. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Therapeutic Radiology and Oncology.

DOI： 10.1093/jrr/rrt047

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

A feasibility study of a novel PET-based molecular image guided radiation therapy (m-IGRT) system was conducted by comparing PET-based digitally reconstructed planar image (PDRI) registration with radiographic registration. We selected a pair of opposing parallel-plane PET systems for the practical implementation of this system. Planar images along the in-plane and cross-plane directions were reconstructed from the parallel-plane PET data. The in-plane and cross-plane FWHM of the profile of 2 mm diameter sources was approximately 1.8 and 8.1 mm, respectively. Therefore, only the reconstructed in-plane image from the parallel-plane PET data was used in the PDRI registration. In the image registration, five different sizes of (18)F cylindrical sources (diameter: 8, 12, 16, 24, 32 mm) were used to determine setup errors. The data acquisition times were 1, 3 and 5 min. Image registration was performed by five observers to determine the setup errors from PDRI registration and radiographic registration. The majority of the mean registration errors obtained from the PDRI registration were not significantly different from those obtained from the radiographic registration. Acquisition time did not appear to result in significant differences in the mean registration error. The mean registration error for the PDRI registration was found to be 0.93 +/- 0.33 mm. This is not statistically different from the radiographic registration which had a mean registration error of 0.92 +/- 0.27 mm. Our results suggest that m-IGRT image registration using PET-based reconstructed planar images along the in-plane direction is feasible for clinical use if PDRI registration is performed at two orthogonal gantry angles.

DOI： 10.1088/0031-9155/56/4/006

Web of Science

PubMed

researchmap

記述言語：日本語   出版者・発行元：公益社団法人日本放射線技術学会  

To estimate the collimator scatter factor, <i>S</i>_c of small field sizes in which a mini-phantom cannot be fully included at the nominal treatment distance (NTD=100 cm), we measured the in-air output of 4 MV and 10 MV X-rays of a Varian's Clinac 2100 C/D using a mini-phantom at NTD and at a long source-to-chamber distance (SCD=200 cm) with field-size defined at the isocenter down to 4.6×4.6cm² and 2.3×2.3cm², respectively. We then compared the fitted curve to the NTD dataset by a cumulative exponential distribution model with that by a cumulative Gaussian distribution (error function) model containing a zero-field extrapolated term derived from the long SCD dataset. The results showed that the zero-field extensions of two fitted curves coincided for a 4 MV X-ray, but a large discrepancy was seen between them for a 10 MV X-ray. Therefore, the <i>S</i>_c of small field sizes not measurable using a mini-phantom at the NTD can be well estimated by applying the cumulative exponential model to the NTD dataset in the case of a 4 MV X-ray beam filtrated with a cone-shaped flattener. However, to estimate the <i>S</i>_c of such small field sizes in the case of a 10 MV X-ray beam filtrated with a bell-shaped flattener, we consider it preferable to also measure in-air output at a long SCD and to apply the cumulative Gaussian model as described here.

DOI： 10.6009/jjrt.64.306

PubMed

CiNii Article

CiNii Books

researchmap

その他リンク： https://jlc.jst.go.jp/DN/JALC/00312601988?from=CiNii

記述言語：日本語   出版者・発行元：日本定位放射線治療学会  

悪性神経膠腫において強度変調回転放射線療法(VMAT)がより有効である症例の選別基準の方法を構築することを目的として、VMATと三次元原体照射法(3DCRT)の治療計画を放射線誘発性脳壊死のリスク指標とした正常組織障害発生確率(NTCP)を用いて比較した。3DCRTで放射線治療が施行された20例を対象とした。PTVinitialについては、Conformity index(CI)に関してVMATが3DCRTよりも有意に向上しており、PTVboostについてもCIはVMATが有意に向上した。正常脳の平均線量については両治療計画間に有意差は認められなかった。3DCRTにおける正常脳のNTCP 5%未満の群においては、3DCRTとVMATのNTCPの中央値は各々1.2%、0.8%であり有意差は認められなかった。しかし、3DCRTにおける正常脳NTCP 5%以上の群においてはそれぞれ9.6%、4.0%であり、VMATで有意に減少した。また、肉眼的標的体積はNTCP 5%以上の群で大きく、カットオフ値は130.5ccであった。

researchmap

記述言語：日本語   出版者・発行元：(株)エムイー振興協会  

当院には動体追跡放射線治療システム「SyncTraX FX4」が世界で初めて導入され、2017年春より運用を開始している。実際の運用期間は短いが、その検証過程において非常に信頼性の高いシステムであることが証明されている。本稿では、その有用性と将来的展望を示していく。(著者抄録)

CiNii Article

researchmap

記述言語：日本語   出版者・発行元：(株)ライフメディコム  

researchmap

記述言語：日本語   出版者・発行元：(NPO)日本歯科放射線学会  

researchmap

記述言語：日本語   出版者・発行元：公益社団法人日本放射線技術学会  

CiNii Article

CiNii Books

researchmap

出版者・発行元：公益社団法人 日本放射線技術学会  

（抄録はありません）

DOI： 10.6009/jjrt.63.1105

CiNii Article

researchmap

開催年月日： 2022年11月

会議種別：ポスター発表  

researchmap

開催年月日： 2022年11月

会議種別：シンポジウム・ワークショップ パネル（指名）  

researchmap

開催年月日： 2022年11月

会議種別：口頭発表（一般）  

researchmap

開催年月日： 2022年11月

会議種別：口頭発表（一般）  

researchmap

開催年月日： 2022年11月

会議種別：ポスター発表  

researchmap

開催年月日： 2022年7月

会議種別：口頭発表（一般）  

researchmap

開催年月日： 2022年5月

会議種別：口頭発表（一般）  

researchmap

開催年月日： 2022年4月

会議種別：口頭発表（一般）  

researchmap

開催年月日： 2022年4月

会議種別：口頭発表（一般）  

researchmap

開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

開催年月日： 2020年10月

記述言語：日本語  

researchmap

開催年月日： 2020年10月

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

開催年月日： 2020年5月 - 2020年6月

記述言語：日本語  

開催地：Web開催  

researchmap

開催年月日： 2020年5月 - 2020年6月

記述言語：日本語  

開催地：Web開催   国名：日本国  

researchmap

開催年月日： 2020年5月 - 2020年6月

記述言語：日本語  

開催地：Web開催   国名：日本国  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

researchmap

researchmap

researchmap

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語  

開催地：Web開催   国名：日本国  

researchmap

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：名古屋   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：仙台   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Chicago   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Antonio   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

開催地：San Antonio   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Antonio   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Francisco   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：仙台   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：仙台   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Antonio   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Antonio   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：仙台   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：仙台   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Nashville   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Nashville   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Nashville   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：つくば   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：シンポジウム・ワークショップ パネル（指名）  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：仙台   国名：日本国  

researchmap

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：広島   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Diego   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Diego   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Diego   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Denver   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Denver   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：福島   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：仙台   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：京都   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：秋田   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：埼玉   国名：日本国  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Washington   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：札幌   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：群馬   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：群馬   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：山形   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Antonio   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Anaheim   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：秋田   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Kyoto   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Kyoto   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Kyoto   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：新潟   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：新潟   国名：日本国  

researchmap

記述言語：英語  

開催地：San Francisco   国名：アメリカ合衆国  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：青森   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：青森   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語  

開催地：Atlanta   国名：アメリカ合衆国  

researchmap

記述言語：日本語  

開催地：大阪   国名：日本国  

researchmap

記述言語：日本語  

開催地：東京   国名：日本国  

researchmap

記述言語：英語  

開催地：Sapporo   国名：日本国  

researchmap

記述言語：英語  

開催地：Sapporo   国名：日本国  

researchmap

記述言語：日本語  

開催地：つくば   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：つくば   国名：日本国  

researchmap

記述言語：英語  

開催地：Hiroshima   国名：日本国  

researchmap

記述言語：日本語  

開催地：熊本   国名：日本国  

researchmap

記述言語：英語  

開催地：Barcelona   国名：スペイン  

researchmap

記述言語：日本語  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：神戸   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：神戸   国名：日本国  

researchmap

記述言語：日本語  

開催地：神戸   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：神戸   国名：日本国  

researchmap

記述言語：英語  

開催地：Miami   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：Sapporo   国名：日本国  

researchmap

記述言語：英語  

開催地：Hakata   国名：日本国  

researchmap

記述言語：日本語  

開催地：仙台   国名：日本国  

researchmap

記述言語：日本語  

開催地：Web開催   国名：日本国  

researchmap

記述言語：日本語  

開催地：Web開催   国名：日本国  

researchmap

記述言語：日本語  

開催地：Web開催   国名：日本国  

researchmap

記述言語：日本語  

開催地：Kyoto   国名：日本国  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京   国名：日本国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Diego   国名：アメリカ合衆国  

researchmap

記述言語：英語   会議種別：ポスター発表  

開催地：San Diego   国名：アメリカ合衆国  

researchmap

記述言語：英語  

開催地：Sapporo   国名：日本国  

researchmap

記述言語：英語  

開催地：Sapporo   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜   国名：日本国  

researchmap

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：横浜  

researchmap

記述言語：日本語   会議種別：ポスター発表  

開催地：札幌   国名：日本国  

researchmap