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237 results on '"Shiomi, Hiroya"'

11. Dosimetric Evaluation of CyberKnife Synchrony System for Liver Tumors With Respiratory Phase Shifts

Author

YOSHIOKA, SAKIKO, AKINO, YUICHI, SHIOMI, HIROYA, HIRATA, TAKERO, KAI, NAOKI, OGAWA, KAZUHIKO, and KOIZUMI, MASAHIKO

Subjects
Pharmacology, Motion, Cancer Research, Fiducial Markers, Liver Neoplasms, Humans, Four-Dimensional Computed Tomography, Radiosurgery, General Biochemistry, Genetics and Molecular Biology, Research Article
Abstract

Background/Aim: This study evaluated the effects of the respiratory phase shifts between liver tumor and chest wall motions on the dose distribution for the CyberKnife Synchrony respiratory tracking system (SRTS). Patients and Methods: Eight patients who received stereotactic body radiotherapy for hepatocellular carcinoma or liver metastases were analyzed. Three-dimensional (3D) motion of the implanted fiducial markers and vertical motion of the sternal bone were derived from the four-dimensional computed tomography (4D-CT) images acquired with a 320-row area detector CT. For each patient, Gaussian random numbers were generated for the standard deviation of the tracking error calculated from the phase shift and a literature. For each voxel of the target, the dose delivered from each beam was calculated 100 times with the random 3D offsets representing the tracking error. Results: The median respiratory phase shifts were 6.0% and 4.6% for the anterior-posterior (AP) and superior-inferior (SI) directions, respectively. The median motion tracking errors influenced by respiratory phase shifts were 1.21 mm and 0.96 mm for the AP and SI directions, respectively. The change in the dose covering 90% of the target (D(90%)) was within 1.1% when median phase shifts were considered. When evaluating the 90(th) percentile of the phase shifts, the D(90%) decreased up to 6.6%. Conclusion: We have developed a technique to estimate the impact of the respiratory phase shifts on the dose distribution of a liver tumor treated with the SRTS. The calculation of the respiratory phase shifts from the area-detector 4D-CT will be valuable to improve the tracking accuracy of the SRTS.

Published
2022

13. Potential benefit of dose‐escalated stereotactic body radiation therapy using CyberKnife for early‐stage primary lung cancer.

Author

Watanabe, Shou, Yamazaki, Hideya, Kimoto, Takuya, Shiomi, Hiroya, Yamada, Kei, and Suzuki, Gen

Subjects
STEREOTACTIC radiotherapy, LUNG cancer, PROGRESSION-free survival, NON-small-cell lung carcinoma, PULMONARY nodules
Abstract

Introduction: The study aimed to evaluate the efficacy and safety of dose‐escalated stereotactic body radiotherapy (SBRT) for primary lung cancer. Methods: Patients with peripherally located T1‐2N0M0 primary lung cancer who underwent SBRT from April 2013 to December 2019 were included. Group A received 60 Gy in five fractions with CyberKnife prescribed at 99% gross tumor volume. Group B received 48 Gy in four fractions by a gantry‐mounted linear accelerator, with isocenter prescription. Cumulative incidence of local failure (LF), progression free survival (PFS), overall survival (OS), and toxicity were retrospectively compared. Results: Groups A and B comprised 39 and 36 patients, respectively. Group A had more patients without histological confirmation (p <.001) and showed lower V20 of bilateral lungs (p =.025). The median follow‐up duration of Group A and B was 22.0 and 21.5 months, respectively, and the 2‐year cumulative incidence of LF, PFS, and OS were.0% versus 11.6% (p =.065), 66.2% versus 62.7% (p =.694), 84.1% versus 81.1% (p =.827), respectively. There was no difference in Grade ≥ 2 toxicity rate between Groups A and B (7.7% vs. 11.1%; p =.704). Conclusion: Dose‐escalated SBRT using CyberKnife showed reduced lung dose and potential benefits for improved local control with comparable toxicity. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Fiducial-Less Respiration Tracking in Radiosurgery

Author

Schweikard, Achim, Shiomi, Hiroya, Fisseler, Jens, Dötter, Manfred, Berlinger, Kajetan, Gehl, Hans-Björn, Adler, John, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Barillot, Christian, editor, Haynor, David R., editor, and Hellier, Pierre, editor

Published
2004
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15. Outpatient High-Dose-Rate Mold Brachytherapy for Lower Gingival Squamous Cell Carcinoma: A First Report

Author

Takeshita, Ami, primary, Shimamoto, Hiroaki, additional, Uchimoto, Yuka, additional, Tsujimoto, Tomomi, additional, Miyamoto, Tetsuo, additional, Kreiborg, Sven, additional, Mallya, Sanjay M, additional, Oda, Michio, additional, Hirata, Takero, additional, Ogawa, Kazuhiko, additional, Shiomi, Hiroya, additional, and Murakami, Shumei, additional

Published
2022
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17. Stereotactic Ablative Radiotherapy Using CyberKnife for Stage I Non-small-cell Lung Cancer: A Retrospective Analysis

Author

HAYASHI, KAZUHIKO, primary, SUZUKI, OSAMU, additional, SHIOMI, HIROYA, additional, NAKAI, MASATAKA, additional, FUJIWARA, KEI, additional, NAKANISHI, ERINA, additional, TATEKAWA, SHOTARO, additional, HIRATA, TAKERO, additional, TAMARI, KEISUKE, additional, HIRATA, HARUHIKO, additional, FUNAKI, SOICHIRO, additional, SEO, YUJI, additional, TAKEDA, YOSHITO, additional, ISOHASHI, FUMIAKI, additional, SHINTANI, YASUSHI, additional, and OGAWA, KAZUHIKO, additional

Published
2021
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37. Definitive re-irradiation using intensity-modulated radiation therapy in cancers of the head and neck, focusing on rare tumors

Author

Doi, Hiroshi, Uemoto, Kenji, Masai, Norihisa, Daisaku Tatsumi, Shiomi, Hiroya, and Ryoong-Jin Oh

Abstract

Purpose: To analyze the outcomes following re-irradiation for local recurrence of rare head and neck tumors. Material and methods: We retrospectively analyzed 11 patients who had received intensity-modulated radiation therapy (IMRT) for recurrent tumors in the head and neck except for laryngopharynx. Results: Primary tumor sites included the maxillary sinus, nasal cavity, and external ear canal in six, three, and two patients, respectively. The median follow-up times were 13 (range, 3–54) months. The median survival time was 17 months with 1- and 2-year survival rates of 63.64 and 39.77%, respectively. Among 11 patients, five experienced local failure in the follow-up period. The 1- and 2-year local control rates were 58 and 47%, respectively. Patients who had received a radiation dose of ≥3 Gy per fraction showed significantly better local control than those receiving less (p = .0419). One patient experienced Grade 3 facial pain as acute toxicity. Late toxicities included radiographic findings of partial central nervous system necrosis in three patients and Grade 3 osteonecrosis and Grade 3 facial nerve disorder in one patient. Conclusions: Re-irradiation of rare head and neck tumors using IMRT for loco-regional recurrence may be an acceptable treatment option.

Published
2018
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38. Feasibility of virtual starshot analysis providing submillimeter radiation isocenter accuracy: A long‐term multi‐institutional analysis

Author

Akino, Yuichi, primary, Fujiwara, Masateru, additional, Mizuno, Hirokazu, additional, Shiomi, Hiroya, additional, Kaneko, Akari, additional, Isohashi, Fumiaki, additional, Seo, Yuji, additional, Suzuki, Osamu, additional, Otani, Keisuke, additional, Tamari, Keisuke, additional, and Ogawa, Kazuhiko, additional

Published
2019
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39. Impacts of respiratory phase shifts on motion‐tracking accuracy of the CyberKnife Synchrony™ Respiratory Tracking System

Author

Akino, Yuichi, primary, Shiomi, Hiroya, additional, Sumida, Iori, additional, Isohashi, Fumiaki, additional, Seo, Yuji, additional, Suzuki, Osamu, additional, Tamari, Keisuke, additional, Otani, Keisuke, additional, Higashinaka, Naokazu, additional, Hayashida, Miori, additional, Mabuchi, Nobuhisa, additional, and Ogawa, Kazuhiko, additional

Published
2019
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40. Feasibility of Salvage Re-irradiation With Stereotactic Radiotherapy for Recurrent Glioma Using CyberKnife

Author

ADACHI, KANA, primary, HAYASHI, KAZUHIKO, additional, KAGAWA, NAOKI, additional, KINOSHITA, MANABU, additional, SUMIDA, IORI, additional, AKINO, YUICHI, additional, SHIOMI, HIROYA, additional, TAMARI, KEISUKE, additional, SUZUKI, OSAMU, additional, HIRAYAMA, RYUICHI, additional, KIJIMA, NORIYUKI, additional, ISOHASHI, FUMIAKI, additional, SEO, YUJI, additional, OTANI, KEISUKE, additional, KISHIMA, HARUHIKO, additional, and OGAWA, KAZUHIKO, additional

Published
2019
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41. Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract

Author

Aibe Norihiro, Nishimura Takuya, Kodani Naohiro, Tsubokura Takuji, Shiomi Hiroya, Yamazaki Hideya, Udono Hiroki, Nishikata Manabu, Baba Yoshimi, Ogita Mikio, Yamashita Koichi, and Kotsuma Tadayuki

Subjects
Medical physics. Medical radiology. Nuclear medicine, R895-920, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Abstract Background To assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise. Methods We quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan. Results The median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm3 (range, 7.17 - 14.3 cm3) and 1.99 for pituitary adenoma, and 6.86 cm3 (range 6.05 - 14.6 cm3) and 2.41 for meningioma. PTV volume was 10.1 ± 1.74 cm3 for group 1 with a margin of 1 -2 mm around the CTV (n = 3) and 9.28 ± 1.8 cm3(p = 0.51) for group 2 with no margin (n = 7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1 ± 3.26 cm3) than group 2 (6.91 ± 0.7 cm3, p = 0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring. Conclusion Quality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract.

Published
2011
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43. Feasibility of synthetic computed tomography generated with an adversarial network for multi-sequence magnetic resonance-based brain radiotherapy.

Author

Koike, Yuhei, Akino, Yuichi, Sumida, Iori, Shiomi, Hiroya, Mizuno, Hirokazu, Yagi, Masashi, Isohashi, Fumiaki, Seo, Yuji, Suzuki, Osamu, and Ogawa, Kazuhiko

Subjects
COMPUTED tomography, MAGNETIC resonance, RADIOTHERAPY
Abstract

The aim of this work is to generate synthetic computed tomography (sCT) images from multi-sequence magnetic resonance (MR) images using an adversarial network and to assess the feasibility of sCT-based treatment planning for brain radiotherapy. Datasets for 15 patients with glioblastoma were selected and 580 pairs of CT and MR images were used. T1-weighted, T2-weighted and fluid-attenuated inversion recovery MR sequences were combined to create a three-channel image as input data. A conditional generative adversarial network (cGAN) was trained using image patches. The image quality was evaluated using voxel-wise mean absolute errors (MAEs) of the CT number. For the dosimetric evaluation, 3D conformal radiotherapy (3D-CRT) and volumetric modulated arc therapy (VMAT) plans were generated using the original CT set and recalculated using the sCT images. The isocenter dose and dose–volume parameters were compared for 3D-CRT and VMAT plans, respectively. The equivalent path length was also compared. The mean MAEs for the whole body, soft tissue and bone region were 108.1 ± 24.0, 38.9 ± 10.7 and 366.2 ± 62.0 hounsfield unit, respectively. The dosimetric evaluation revealed no significant difference in the isocenter dose for 3D-CRT plans. The differences in the dose received by 2% of the volume (D 2%), D 50% and D 98% relative to the prescribed dose were <1.0%. The overall equivalent path length was shorter than that for real CT by 0.6 ± 1.9 mm. A treatment planning study using generated sCT detected only small, clinically negligible differences. These findings demonstrated the feasibility of generating sCT images for MR-only radiotherapy from multi-sequence MR images using cGAN. [ABSTRACT FROM AUTHOR]

Published
2020
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