2024/03/21 更新

写真a

ヨゴ カツノリ
余語 克紀
YOGO Katsunori
所属
大学院医学系研究科 総合保健学専攻 バイオメディカルイメージング情報科学 助教
大学院担当
大学院医学系研究科
学部担当
医学部(保健学科)
職名
助教
連絡先
メールアドレス
外部リンク

学位 1

  1. 博士(理学) ( 2013年3月 ) 

研究キーワード 10

  1. 放射線生物学

  2. 放射線治療

  3. 医学物理

  4. ナノメディシン

  5. チェレンコフ光

  6. シンチレータ

  7. DNA損傷

  8. 生物物理

  9. ナノテクノロジー

  10. イメージング

研究分野 9

  1. ライフサイエンス / 放射線科学  /  医学物理学

  2. エネルギー / 量子ビーム科学  /  医学物理学

  3. 自然科学一般 / 素粒子、原子核、宇宙線、宇宙物理にする実験

  4. ライフサイエンス / 生物物理学  / DNA damage

  5. ライフサイエンス / 放射線科学

  6. ライフサイエンス / 分子生物学  / Radiation Biology

  7. その他 / その他  / Medical Physics

  8. ナノテク・材料 / ナノバイオサイエンス

  9. ライフサイエンス / 放射線科学

▼全件表示

現在の研究課題とSDGs 3

  1. 放射線誘発の発光を利用した放射線治療の品質保証ツール開発

  2. 放射線治療併用の放射線防護剤の開発

  3. 放射線治療併用の放射線増感剤の開発

経歴 1

  1. 名古屋大学   大学院医学系研究科 総合保健学専攻 バイオメディカルイメージング情報科学   助教

    2020年4月 - 現在

所属学協会 10

  1. 日本医学物理学会

  2. 日本応用物理学会

  3. ナノ学会

  4. 日本放射線影響学会

  5. 日本放射線腫瘍学会

  6. 日本放射線腫瘍学会

  7. 日本放射線影響学会

  8. 日本応用物理学会

  9. 日本医学物理学会

  10. ナノ学会

▼全件表示

受賞 3

  1. 「貴金属に関わる研究助成金」奨励賞

    2022年3月   田中貴金属記念財団  

     詳細を見る

    受賞区分:出版社・新聞社・財団等の賞 

  2. 優秀研究賞受賞(平成29年)

    2017年4月   日本医学物理学会  

  3. 優秀研究賞受賞(平成27年)

    2015年4月   日本医学物理学会  

 

論文 39

  1. A comparative study of EM-CCD and CMOS cameras for particle ion trajectory imaging 査読有り

    Yamamoto, S; Yoshino, M; Nakanishi, K; Yogo, K; Kamada, K; Yoshikawa, A; Kataoka, J

    APPLIED RADIATION AND ISOTOPES   204 巻   頁: 111143 - 111143   2024年2月

     詳細を見る

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

    High-resolution and real-time imaging of particle ion trajectories is essential in nuclear medicine and nuclear engineering. One potential method to achieve high-resolution real-time trajectory imaging of particle ions involves utilizing an imaging system that integrates a scintillator plate with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera. However, acquiring an EM-CCD camera might prove challenging due to the discontinuation of CCD sensor manufacturing by vendors. As an alternative imaging approach, a low-noise, high-sensitivity camera utilizing a cooled complementary metal-oxide-semiconductor (CMOS) sensor offers a promising solution for imaging particle ion trajectories. Yet, it remains uncertain whether CMOS-based cameras can perform as effectively as CCD-based cameras in capturing particle ion trajectories. To address these concerns, we conducted a comparative analysis of the imaging performance between a CMOS-based system and an EM-CCD-based system for capturing alpha particle trajectories. The results revealed that both systems could image the trajectories of alpha particle, but the spatial resolution with the CMOS-based camera exceeded that of the EM-CCD-based camera, primarily due to the smaller pixel size of the sensor. While the signal-to-noise ratio (SNR) of the trajectory image from the CMOS-based camera initially lagged behind that from the EM-CCD-based camera, this disparity was mitigated by implementing binning techniques on the CMOS-based camera images. In conclusion, our findings suggest that a cooled CMOS camera could serve as a viable alternative for imaging particle ion trajectories.

    DOI: 10.1016/j.apradiso.2023.111143

    Web of Science

    Scopus

    PubMed

  2. Estimating blurless and noise-free Ir-192 source images from gamma camera images for high-dose-rate brachytherapy using a deep-learning approach 査読有り

    Nakanishi, K; Yamamoto, S; Yabe, T; Yogo, K; Noguchi, Y; Okudaira, K; Kawachi, N; Kataoka, J

    BIOMEDICAL PHYSICS & ENGINEERING EXPRESS   10 巻 ( 1 )   2024年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Biomedical Physics and Engineering Express  

    Objective. Precise monitoring of the position and dwell time of iridium-192 (Ir-192) during high-dose-rate (HDR) brachytherapy is crucial to avoid serious damage to normal tissues. Source imaging using a compact gamma camera is a potential approach for monitoring. However, images from the gamma camera are affected by blurring and statistical noise, which impact the accuracy of source position monitoring. This study aimed to develop a deep-learning approach for estimating ideal source images that reduce the effect of blurring and statistical noise from experimental images captured using a compact gamma camera. Approach. A double pix2pix model was trained using the simulated gamma camera images of an Ir-192 source. The first model was responsible for denoising the Ir-192 images, whereas the second model performed super resolution. Trained models were then applied to the experimental images to estimate the ideal images. Main results. At a distance of 100 mm between the compact gamma camera and the Ir-192 source, the difference in full width at half maximum (FWHM) between the estimated and actual source sizes was approximately 0.5 mm for a measurement time of 1.5 s. This difference has been improved from approximately 2.7 mm without the use of DL. Even with a measurement time of 0.1 s, the ideal images could be estimated as accurately as in the 1.5 s measurements. This method consistently achieved accurate estimations of the source images at any position within the field of view; however, the difference increased with the distance between the Ir-192 source and the compact gamma camera. Significance. The proposed method successfully provided estimated images from the experimental images within errors smaller than 0.5 mm at 100 mm. This method is promising for reducing blurring and statistical noise from the experimental images, enabling precise real-time monitoring of Ir-192 sources during HDR brachytherapy.

    DOI: 10.1088/2057-1976/ad0bb2

    Web of Science

    Scopus

    PubMed

    その他リンク: https://iopscience.iop.org/article/10.1088/2057-1976/ad0bb2/pdf

  3. Sub-micrometer real-time imaging of trajectory of alpha particles using GAGG plate and CMOS camera 査読有り

    Yamamoto, S; Yoshino, M; Nakanishi, K; Yogo, K; Kamada, K; Yoshikawa, A; Koshikawaa, N; Kataokaa, J

    JOURNAL OF INSTRUMENTATION   18 巻 ( 10 ) 頁: T10003 - T10003   2023年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Instrumentation  

    High-resolution and real-time imaging of the trajectories of alpha particles is desired in nuclear medicine and nuclear engineering. Although an imaging method using a scintillator plate combined with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera is a possible method of obtaining high-resolution trajectory images, the spatial resolution of the system is limited to ∼2 μm. To overcome the spatial resolution limitations of this method on trajectory imaging, we used a cooled complementally metal oxide (CMOS) camera in which the sensor had a much larger number of pixels, which were also smaller. Using the CMOS camera based imaging system, we could measure the trajectories of alpha particles in real time with the spatial resolution of 0.34 μm FWHM. With smoothing of the images to reduce image noise, spatial resolution was still kept to less than 0.75 μm. We conclude that this CMOS camera-based alpha-particle trajectory-imaging system is promising for alpha-particle or other particles imaging where ultrahigh spatial resolution is required.

    DOI: 10.1088/1748-0221/18/10/T10003

    Web of Science

    Scopus

    その他リンク: https://iopscience.iop.org/article/10.1088/1748-0221/18/10/T10003/pdf

  4. Luminescence imaging of water irradiated by protons under FLASH radiation therapy conditions 査読有り 国際誌

    Yogo Katsunori, Kodaira Satoshi, Kusumoto Tamon, Kitamura Hisashi, Toshito Toshiyuki, Iwata Hiromitsu, Umezawa Masumi, Yamada Masashi, Miyoshi Takuto, Komori Masataka, Yasuda Hiroshi, Kataoka Jun, Yamamoto Seiichi

    PHYSICS IN MEDICINE AND BIOLOGY   68 巻 ( 15 )   2023年8月

     詳細を見る

    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)   出版者・発行元:Physics in Medicine and Biology  

    Objective. FLASH radiation therapy with ultrahigh dose rates (UHDR) has the potential to reduce damage to normal tissue while maintaining anti-tumor efficacy. However, rapid and precise dose distribution measurements remain difficult for FLASH radiation therapy with proton beams. To solve this problem, we performed luminescence imaging of water following irradiation by a UHDR proton beam captured using a charge-coupled device camera. Approach. We used 60 MeV proton beams with dose rates of 0.03-837 Gy s−1 from a cyclotron. Therapeutic 139.3 MeV proton beams with dose rates of 0.45-4320 Gy s−1 delivered by a synchrotron-based proton therapy system were also tested. The luminescent light intensity induced by the UHDR beams was compared with that produced by conventional beams to compare the dose rate dependency of the light intensity and its profile. Main results. Luminescence images of water were clearly visualized under UHDR conditions, with significantly shorter exposure times than those with conventional beams. The light intensity was linearly proportional to the delivered dose, which is similar to that of conventional beams. No significant dose-rate dependency was observed for 0.03-837 Gy s−1. The light-intensity profiles of the UHDR beams agreed with those of conventional beams. The results did not differ between accelerators (synchrotron or cyclotron) and beam energies. Significance. Luminescence imaging of water is achievable with UHDR proton beams as well as with conventional beams. The proposed method should be suitable for rapid and easy quality assurance investigations for proton FLASH therapy, because it facilitates real-time, filmless measurements of dose distributions, and is useful for rapid feedback.

    添付ファイル: 0712広報修正_PressRelease0614Proton1y3.pdf

    DOI: 10.1088/1361-6560/ace60b

    Web of Science

    Scopus

    PubMed

  5. [展望・解説] 放射線治療「せめる/まもる」薬剤の探索;輪ゴム DNAの損傷評価 査読有り

    余語 克紀

    放射線化学   ( 115 )   2023年4月

     詳細を見る

    担当区分:筆頭著者, 責任著者  

  6. Short-time sequential high-energy gamma photon imaging using list-mode data acquisition system for high-dose-rate brachytherapy 査読有り

    Nagata Jura, Yamamoto Seiichi, Yabe Takuya, Yogo Katsunori, Nakanishi Kohei, Noguchi Yumiko, Okudaira Kuniyasu, Kamada Kei, Yoshikawa Akira, Kataoka Jun

    MEDICAL PHYSICS   49 巻 ( 12 ) 頁: 7703 - 7714   2022年12月

     詳細を見る

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

    Purpose: Measurement of the dwell time and moving speed of a high-activity iridium-192 (Ir-192) source used for high-dose-rate (HDR) brachytherapy is important for estimating the precise dose delivery to a tumor. For this purpose, we used a cerium-doped yttrium aluminum perovskite (YA1O3:YAP(Ce)) gamma camera system, combined with a list-mode data acquisition system that can acquire short-time sequential images, and measured the dwell times and moving speeds of the Ir-192 source. Methods: Gamma photon imaging was conducted using the gamma camera in list mode for the Ir-192 source of HDR brachytherapy with fixed dwell times and positions. The acquired list-mode images were sorted to millisecond-order interval time sequential images to evaluate the dwell time at each position. Time count rate curves were derived to calculate the dwell time at each source position and moving speed of the source. Results: We could measure the millisecond-order time sequential images for the Ir-192 source. The measured times for the preset dwell times of 2 s and 10 s were 1.98 to 2.00 s full width at half maximum (FWHM) and 10.0 s FWHM, respectively. The dwell times at the first dwell position were larger than those at other positions. We also measured the moving speeds of the source after the dwells while moving back to the afterloader and found the speed increased with the distance from the edge of the field of view to the last dwell position. Conclusion: We conclude that millisecond-order time sequential imaging of the Ir-192 source is possible by using a gamma camera and is useful for evaluating the dwell times and moving speeds of the Ir-192 source.

    DOI: 10.1002/mp.15957

    Web of Science

    Scopus

    PubMed

  7. Short time sequential luminescence imaging of water during irradiation by protons 査読有り

    Yamamoto Seiichi, Yabe Takuya, Yogo Katsunori, Akagi Takashi, Kataoka Jun

    JOURNAL OF INSTRUMENTATION   17 巻 ( 12 )   2022年12月

     詳細を見る

    出版者・発行元:Journal of Instrumentation  

    Although luminescence imaging of water during irradiation by particle ions is a promising method for dose estimation, it has only been tried for static images in which temporal information is not included. In addition to the positional distribution of the beam, temporal information is also important because the beams from a synchrotron-based therapy system have short pulse shapes called spills. The temporal information is also important for high dose rate, short-time radiotherapy, or so-called FLASH radiotherapy. To measure the particle ion beam distributions with precise temporal information, we conducted short time sequential luminescence imaging of protons. First, we measured short time sequential luminescence images during irradiation of a water phantom by 150-MeV protons using a cooled charge-coupled device (CCD) camera at 0.143-s intervals. With this imaging, the images showed beam distributions, but the shapes of the spill were not precisely evaluated in time intensity curves due to the insufficient sampling rate of the imaging. Then we measured short time sequential optical images with 0.053-s intervals. With this imaging, the images showed that the beam distributions in the spill shape could be measured, but the image and depth profiles evaluated from the images were noisy due to the insufficient light intensity. Consequently, we measured short time sequential luminescence images during irradiation of fluorescein (FS) water by 150-MeV protons. Since FS water produced ∼10 times higher luminescence, we could obtain high-intensity images enabling us to evaluate the time intensity curves based on the shape of the spills during measurement with 0.053-s intervals. The depth profiles of the beam were also obtained from the measured images. With these results, we confirmed that time sequential luminescence imaging was possible and, in such cases, FS water images measured at 0.053-s intervals are most promising to measure the short time sequential luminescence images during irradiation of protons.

    DOI: 10.1088/1748-0221/17/12/T12001

    Web of Science

    Scopus

  8. Optimization of the energy window setting in Ir-192 source imaging for high-dose-rate brachytherapy using a YAP(Ce) gamma camera 査読有り

    Nagata Jura, Nakanishi Kohei, Yamamoto Seiichi, Yabe Takuya, Yogo Katsunori, Noguchi Yumiko, Okudaira Kuniyasu, Kamada Kei, Yoshikawa Akira, Kataoka Jun

    PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS   103 巻   頁: 66 - 73   2022年11月

     詳細を見る

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

    Purpose: Although real-time imaging of the high-activity iridium-192 (Ir-192) source position during high-dose-rate (HDR) brachytherapy using a high-energy gamma camera system is a promising approach, the energy window was not optimized for spatial resolution or scatter fraction. Methods: By using a list-mode data-acquisition system that can acquire energy information of a cerium-doped yttrium aluminum perovskite (YA1O3: YAP(Ce)) gamma camera, we tried to optimize the energy window's setting to improve the spatial resolution and reduce scatter fraction. Results: The spatial resolution was highest for the central energy of the window at ∼300 keV. The scatter fraction was also smallest for the central energy of the window at ∼300 keV, and the scatter fraction was more than 48 % smaller than that for the full energy window. Conclusions: We clarified that the spatial resolution can be improved and the scatter fraction can be reduced through optimizing the energy window of the YAP(Ce) gamma camera by setting the central energy of the window to ∼300 keV for HDR brachytherapy.

    DOI: 10.1016/j.ejmp.2022.09.017

    Web of Science

    Scopus

    PubMed

  9. Correcting angular dependencies using non-polarized components of Cherenkov light in water during high-energy X-ray irradiation 査読有り

    Toyonaga Chihiro, Yamamoto Seiichi, Yabe Takuya, Okudaira Kuniyasu, Yogo Katsunori, Hirano Yoshiyuki, Kataoka Jun

    MEDICAL PHYSICS   49 巻 ( 8 ) 頁: 5409 - 5416   2022年8月

     詳細を見る

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

    Objective: Dose distribution measurements of high-energy X-rays from medical linear accelerators (LINAC) in water are important for quality control (QC) of the system. Although Cherenkov-light imaging is a useful method for measuring the high-energy X-ray dose distribution, depth profiles have an underestimated dose at increased depths due to the angular dependency of the Cherenkov light generated in water. In this study, we use a linear polarizer to separate the majority of polarized components from the majority of unpolarized components of Cherenkov-light images in water and then use this information to correct for angular dependencies. Methods: A water phantom, a cooled charge-coupled device (CCD) camera, and a polarizer were installed in a black box. Then, the water phantom was irradiated from the upper side with 6 or 10 MV X-rays, and the Cherenkov light generated in water was imaged with the polarizer axis at both parallel and perpendicular orientations to the beam. By using these images from the two orientations relative to the beam, we corrected the angular dependency of the Cherenkov light. Results: By subtracting the images measured with the polarizer perpendicular to the beams from the images measured with the polarizer parallel to the beams, we could obtain images with only the polarized components. Using these images, we could calculate the images with non-polarized components that had similar depth profiles to those calculated with a planning system. The average difference between corrected depth profiles and those calculated with the planning system was less than 1%, while that between uncorrected depth profiles and the planning system was more than 8.3% in depths of water from 20 to 100 mm. Conclusion: We conclude that the use of the polarizer has the potential to improve the accuracy of dose distribution in Cherenkov-light imaging of water using high-energy X-rays.

    DOI: 10.1002/mp.15794

    Web of Science

    Scopus

    PubMed

    その他リンク: https://onlinelibrary.wiley.com/doi/full-xml/10.1002/mp.15794

  10. Three-dimensional (3D) optical imaging of electron beam and X-rays from medical linear accelerators (LINAC) using a plastic scintillator plate in water 査読有り

    Yamamoto Seiichi, Hiramatsu Airi, Shimizu Yui, Yabe Takuya, Yogo Katsunori, Kataoka Jun

    JOURNAL OF INSTRUMENTATION   17 巻 ( 8 )   2022年8月

     詳細を見る

    記述言語:日本語   出版者・発行元:Journal of Instrumentation  

    Although optical imaging of electron beams and X-rays from medical linear accelerators (LINAC) is a possible method for dose distribution measurements, it has been limited to two-dimensional (2D) projection images. For the precise measurement of an optical image of electron beams and X-rays, three-dimensional (3D) imaging is desired. To measure 3D dose distributions, we conducted imaging of electron beams and X-rays using a plastic scintillator plate set in a water phantom. When this plate was immersed in the water phantom, irradiation with electron beams or X-rays was carried out from along the plate's sides. Optical images of the scintillator plate were acquired using a charge-coupled device (CCD) camera from the side during irradiation with electron beams and X-rays. Measurements were conducted at 6 MeV, 9 MeV and 12 MeV for electron beams and at 6 MV and 10 MV for X-rays. The imaging system was set on the bed of the LINAC and moved at 10-mm steps perpendicular to the beam direction to acquire a set of sliced optical images of the beams. A set of these sliced images were stacked and interpolated to form 3D optical images. For the 3D images, after the correction of the Cherenkov-light component in the images, the relative depth and lateral doses were evaluated. From the relative depth doses of electron beams, the half-value depths could be evaluated within an error of 1.3 mm. Lateral widths could be evaluated within an error of less than 2 mm parallel to the plastic scintillator and less than 6.5 mm perpendicular to it. From the relative depth doses of X-rays, the average difference between the measured value and that by a planning system was within an error of 2 %. Lateral widths could be evaluated within an error of less than 0.68 mm parallel to the plastic scintillator and less than 2.6 mm perpendicular to it. We confirmed that 3D imaging of electron beams and X-rays using plastic scintillator plate is feasible and is a promising method for measuring dose images at any position.

    DOI: 10.1088/1748-0221/17/08/P08015

    Web of Science

    Scopus

  11. Three-dimensional (3D) optical imaging of electron beam and X-rays from medical linear accelerators (LINAC) using a plastic scintillator plate in water 査読有り

    Seiichi Yamamoto, Airi Hiramatsu, Yui Shimizu, Takuya Yabe, Katsunori Yogo, Jun Kataoka

    Journal of Instrumentation   17 巻   頁: P08015   2022年8月

  12. Real-time tracking of source movement by Cherenkov emission imaging for high-dose-rate brachytherapy 査読有り

    Yogo K., Tatsuno Y., Shimo T., Noguchi Y., Okudaira K., Nozawa M., Ishiyama H., Yasuda H., Oguchi H., Yamamoto S.

    JOURNAL OF INSTRUMENTATION   17 巻 ( 7 )   2022年7月

     詳細を見る

    記述言語:日本語   出版者・発行元:Journal of Instrumentation  

    Quality assurance (QA) of the source movement is essential for ensuring the safe delivery of high-dose-rate (HDR) brachytherapy. Here, we proposed a simple and effective method for real-time tracking of the source movement in high-dose-rate brachytherapy based on Cherenkov emission imaging. The Cherenkov light emitted from water irradiated by 192Ir-source γ-rays was captured using a high-sensitivity video camera. The source positions and dwell intervals were determined from the light images and compared with the preset values. The source dwell times and transit speeds were measured from the time course of the source positions. The brightness profiles were compared with the dose distributions provided by the treatment planning system. The source movements were visualized in real time as a movie of Cherenkov light emissions. The source positional intervals measured from the Cherenkov emission images agreed well to the preset values within 0.3 mm. The source dwell times were comparable to the preset values within 0.2 s, and the transit speeds were similar to those of previous reports. The brightness distributions agreed with the dose distributions within approximately 40%, except near the source center. The proposed Cherenkov method has good potential for tracking the source movement in real time in brachytherapy, as it could enable simultaneous measurements of the source positions, dwell times, and dose distributions.

    DOI: 10.1088/1748-0221/17/07/T07001

    Web of Science

    Scopus

  13. Radiosensitization Effect of Gold Nanoparticles on Plasmid DNA Damage Induced by Therapeutic MV X-rays 査読有り

    Yogo Katsunori, Misawa Masaki, Shimizu Hidetoshi, Kitagawa Tomoki, Hirayama Ryoichi, Ishiyama Hiromichi, Yasuda Hiroshi, Kametaka Satoshi, Takami Seiichi

    NANOMATERIALS   12 巻 ( 5 ) 頁: 771 - 771   2022年3月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.3390/nano12050771

    Web of Science

    PubMed

  14. 総説「プラスミドDNA損傷を指標とした放射線保護剤/増感剤の探索-放射線治療併用のアミノ酸と金ナノ粒子を中心として-」 招待有り 査読有り

    余語 克紀、平山 亮一、保田 浩志、三澤 雅樹

    放射線生物研究   56 巻 ( 3 ) 頁: 260 - 279   2021年9月

     詳細を見る

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

  15. Protective Effects of Amino Acids on Plasmid DNA Damage Induced by Therapeutic Carbon Ions 査読有り 国際誌

    Yogo Katsunori, Murayama Chieko, Hirayama Ryoichi, Matsumoto Ken-ichiro, Nakanishi Ikuo, Ishiyama Hiromichi, Yasuda Hiroshi

    RADIATION RESEARCH   196 巻 ( 2 ) 頁: 197 - 203   2021年8月

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Radiation Research  

    Radioprotectors with few side effects are useful for carbon-ion therapy, which directly induces clustering damage in DNA. With the aim of finding the most effective radioprotector, we investigated the effects of selected amino acids which might have chemical DNA-repair functions against therapeutic carbon ions. In the current study, we employed five amino acids: tryptophan (Trp), cysteine (Cys), methionine (Met), valine (Val) and alanine (Ala). Samples of supercoiled pBR322 plasmid DNA with a 17 mM amino acid were prepared in TE buffer (10 mM Tris, 1 mM ethylenediaminetetraacetic acid, pH 7.5). Phosphate buffered saline (PBS) was also used in assays of the 0.17 mM amino acid. The samples were irradiated with carbon-ion beams (290 MeV/u) on 6 cm spread-out Bragg peak at the National Institute of Radiological Sciences and Heavy Ion Medical Accelerator in Chiba, Japan. Breaks in the DNA were detected as changes in the plasmids and quantified by subsequent electrophoresis on agarose gels. DNA damage yields and protection factors for each amino acid were calculated as ratios relative to reagent-free controls. Trp and Cys showed radioprotective effects against plasmid DNA damage induced by carbon-ion beam, both in PBS and TE buffer, comparable to those of Met. The double-strand break (DSB) yields and protective effects of Trp were comparable to those of Cys. The yields of both single-strand breaks and DSBs correlated with the scavenging capacity of hydroxyl radicals (rate constant for scavenging hydroxyl radicals multiplied by the amino acid concentration) in bulk solution. These data indicate that the radioprotective effects of amino acids against plasmid DNA damage induced by carbon ions could be explained primarily by the scavenging capacity of hydroxyl radicals. These findings suggest that some amino acids, such as Trp, Cys and Met, have good potential as radioprotectors for preventing DNA damage in normal tissues in carbon-ion therapy.

    DOI: 10.1667/RADE-21-00033.1

    Web of Science

    Scopus

    PubMed

  16. Three-dimensional dose-distribution measurement of therapeutic carbon-ion beams using a ZnS scintillator sheet. 査読有り 国際誌

    Yogo K, Tsuneda M, Horita R, Souda H, Matsumura A, Ishiyama H, Hayakawa K, Kanai T, Yamamoto S

    Journal of radiation research     2021年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1093/jrr/rrab036

    PubMed

  17. Source position measurement by Cherenkov emission imaging from applicators for high-dose-rate brachytherapy. 査読有り 国際誌

    Yogo K, Noguchi Y, Okudaira K, Nozawa M, Ishiyama H, Okamoto H, Yasuda H, Oguchi H, Yamamoto S

    Medical physics   48 巻 ( 1 ) 頁: 488 - 499   2021年1月

     詳細を見る

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

    Purpose: We developed a novel and simple method to measure the source positions in applicators directly for high-dose-rate (HDR) brachytherapy based on Cherenkov emission imaging, and evaluated the performance. Methods: The light emission from plastic applicators used in cervical cancer treatments, irradiated by an 192Ir γ-ray source, was captured using a charge-coupled device camera. Moreover, we attached plastics of different shapes, including tapes, tubes, and plates to a metal applicator, to use as screens for the Cherenkov imaging. We determined the source positions and dwell intervals from the light profiles along with the applicator and compared these with preset values and dummy marker measurements. Results: The source positions and dwell intervals measured from the light images were comparable to the dummy marker measurements and preset values. The distance from the applicator tip to the first source positions agreed with the dummy marker measurements within 0.2 mm for the plastic tandem. The dwell intervals measured using the Cherenkov method agreed with the preset values within 0.6 mm. The distances measured with three plastic types on the metal applicator also agreed with the dummy marker measurements within 0.2 mm. The dwell intervals measured using the plastic tape agreed with the preset values within 0.7 mm. Conclusions: The proposed method should be suitable for rapid and easy quality assurance (QA) investigations in HDR brachytherapy, as it enables source position using a single image. The method allows for real-time, filmless measurements of the source positions to be obtained and is useful for rapid feedback in QA procedures.

    DOI: 10.1002/mp.14606

    Web of Science

    Scopus

    PubMed

  18. Effect of Gold Nanoparticle Radiosensitization on Plasmid DNA Damage Induced by High-Dose-Rate Brachytherapy 査読有り 国際誌

    Yogo Katsunori, Misawa Masaki, Shimizu Morihito, Shimizu Hidetoshi, Kitagawa Tomoki, Hirayama Ryoichi, Ishiyama Hiromichi, Furukawa Takako, Yasuda Hiroshi

    INTERNATIONAL JOURNAL OF NANOMEDICINE   16 巻   頁: 359 - 370   2021年

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Journal of Nanomedicine  

    Purpose: Gold nanoparticles (AuNPs) are candidate radiosensitizers for medium-energy photon treatment, such as γ-ray radiation in high-dose-rate (HDR) brachytherapy. However, high AuNP concentrations are required for sufficient dose enhancement for clinical applica-tions. Here, we investigated the effect of positively (+) charged AuNP radiosensitization of plasmid DNA damage induced by 192Ir γ-rays, and compared it with that of negatively (−) charged AuNPs. Methods: We observed DNA breaks and reactive oxygen species (ROS) generation in the presence of AuNPs at low concentrations. pBR322 plasmid DNA exposed to 64 ng/mL AuNPs was irradiated with 192Ir γ-rays via HDR brachytherapy. DNA breaks were detected by observing the changes in the form of the plasmid and quantified by agarose gel electro-phoresis. The ROS generated by the AuNPs were measured with the fluorescent probe sensitive to ROS. The effects of positively (+) and negatively (−) charged AuNPs were compared to study the effect of surface charge on dose enhancement. Results: +AuNPs at lower concentrations promoted a comparable level of radiosensitization by producing both single-stranded breaks (SSBs) and double-stranded breaks (DSBs) than those used in cell assays and Monte Carlo simulation experiments. The dose enhancement factor (DEF) for +AuNPs was 1.3 ± 0.2 for SSBs and 1.5 ± 0.4 for DSBs. The ability of +AuNPs to augment plasmid DNA damage is due to enhanced ROS generation. While −AuNPs generated similar ROS levels, they did not cause significant DNA damage. Thus, dose enhancement using low concentrations of +AuNPs presumably occurred via DNA binding or increasing local +AuNP concentration around the DNA. Conclusion: +AuNPs at low concentrations displayed stronger radiosensitization compared to −AuNPs. Combining +AuNPs with 192Ir γ-rays in HDR brachytherapy is a candidate method for improving clinical outcomes. Future development of cancer cell-specific +AuNPs would allow their wider application for HDR brachytherapy.

    DOI: 10.2147/IJN.S292105

    Web of Science

    Scopus

    PubMed

  19. Potential Mechanisms for Protective Effect of D-Methionine on Plasmid DNA Damage Induced by Therapeutic Carbon Ions

    Yogo Katsunori, Murayama Chieko, Fujisawa Yoshiki, Maeyama Takuya, Hirayama Ryoichi, Ogawa Yukihiro, Matsumoto Ken-ichiro, Nakanishi Ikuo, Yasuda Hiroshi, Ishiyama Hiromichi, Hayakawa Kazushige

    RADIATION RESEARCH   193 巻 ( 6 ) 頁: 513 - 519   2020年6月

     詳細を見る

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

    DOI: 10.1667/RR15502.1

    Web of Science

    Scopus

    PubMed

  20. Scintillator screen for measuring low-dose halo in scanning carbon-ion therapy

    Yogo Katsunori, Tatsuno Yuya, Souda Hikaru, Matsumura Akihiko, Tsuneda Masato, Hirano Yoshiyuki, Ishiyama Hiromichi, Saito Akito, Ozawa Shuichi, Nagata Yasushi, Nakano Takashi, Hayakawa Kazushige, Kanai Tatsuaki

    RADIATION MEASUREMENTS   133 巻   2020年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.radmeas.2020.106299

    Web of Science

    Scopus

  21. Imaging Cherenkov emission for quality assurance of high-dose-rate brachytherapy

    Yogo Katsunori, Matsushita Akihiro, Tatsuno Yuya, Shimo Takahiro, Hirota Seiko, Nozawa Marika, Ozawa Shuichi, Ishiyama Hiromichi, Yasuda Hiroshi, Nagata Yasushi, Hayakawa Kazushige

    SCIENTIFIC REPORTS   10 巻 ( 1 ) 頁: 3572   2020年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1038/s41598-020-60519-z

    Web of Science

    Scopus

    PubMed

  22. A method of absorbed dose determination using vitamin B2 water for optical imaging of X-rays from high energy medical linear accelerators

    Toyonaga Chihiro, Yamamoto Seiichi, Yogo Katsunori, Okudaira Kuniyasu, Kawabata Fumitaka, Nakaya Takayoshi, Oguchi Hiroshi

    RADIATION MEASUREMENTS   131 巻   2020年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.radmeas.2019.106227

    Web of Science

    Scopus

  23. Scintillator screen for measuring dose distribution in scanned carbon-ion therapy

    Yogo Katsunori, Tatsuno Yuya, Souda Hikaru, Matsumura Akihiko, Tsuneda Masato, Hirano Yoshiyuki, Ishiyama Hiromichi, Saito Akito, Ozawa Shuichi, Nagata Yasushi, Nakano Takashi, Hayakawa Kazushige, Kanai Tatsuaki

    RADIATION MEASUREMENTS   129 巻   2019年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.radmeas.2019.106207

    Web of Science

    Scopus

  24. Imaging of Ir-192 source using a high energy gamma camera for high-dose-rate brachytherapy

    Yamamoto Seiichi, Yogo Katsunori, Noguchi Yumiko, Nakaya Takayoshi, Okudaira Kuniyasu

    RADIATION MEASUREMENTS   126 巻   2019年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.radmeas.2019.106128

    Web of Science

    Scopus

  25. Three-dimensional (3D) dose distribution measurements of proton beam using a glass plate

    Horita Ryo, Yamamoto Seiichi, Yogo Katsunori, Komori Masataka, Toshito Toshiyuki

    BIOMEDICAL PHYSICS & ENGINEERING EXPRESS   5 巻 ( 4 )   2019年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1088/2057-1976/ab169e

    Web of Science

    Scopus

  26. Tolerance levels of mass density for CT number calibration in photon radiation therapy

    Nakao Minoru, Ozawa Shuichi, Yogo Katsunori, Miura Hideharu, Yamada Kiyoshi, Hosono Fumika, Hayata Masahiro, Miki Kentaro, Nakashima Takeo, Ochi Yusuke, Kawahara Daisuke, Morimoto Yoshiharu, Yoshizaki Toru, Nozaki Hiroshige, Habara Kosaku, Nagata Yasushi

    JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS   20 巻 ( 6 ) 頁: 45-52   2019年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1002/acm2.12601

    Web of Science

    Scopus

    PubMed

  27. Estimation of the three-dimensional (3D) dose distribution of electron beams from medical linear accelerator (LINAC) using plastic scintillator plate

    Horita Ryo, Yamamoto Seiichi, Yogo Katsunori, Hirano Yoshiyuki, Okudaira Kuniyasu, Kawabata Fumitaka, Nakaya Takayoshi, Komori Masataka, Oguchi Hiroshi

    RADIATION MEASUREMENTS   124 巻   頁: 103-108   2019年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.radmeas.2019.04.002

    Web of Science

    Scopus

  28. Risk factors for radiotherapy incidents: a single institutional experience.

    Ishiyama H, Shuto N, Terazaki T, Noda S, Ishigami M, Yogo K, Hayakawa K

    Medical dosimetry : official journal of the American Association of Medical Dosimetrists     2018年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.meddos.2017.12.006

    PubMed

  29. Tolerance levels of CT number to electron density table for photon beam in radiotherapy treatment planning system.

    Nakao M, Ozawa S, Yamada K, Yogo K, Hosono F, Hayata M, Saito A, Miki K, Nakashima T, Ochi Y, Kawahara D, Morimoto Y, Yoshizaki T, Nozaki H, Habara K, Nagata Y

    Journal of applied clinical medical physics   19 巻 ( 1 ) 頁: 271-275   2018年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1002/acm2.12226

    PubMed

  30. Split-VMAT technique to control the expiratory breath-hold time in liver stereotactic body radiation therapy.

    Lin YH, Ozawa S, Miura H, Yogo K, Nakashima T, Miki K, Tsuda S, Ochi Y, Kawahara D, Kimura T, Saito A, Nagata Y

    Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)   40 巻   頁: 17-23   2017年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.ejmp.2017.06.022

    PubMed

  31. Practical use of a plastic scintillator for quality assurance of electron beam therapy.

    Yogo K, Tatsuno Y, Tsuneda M, Aono Y, Mochizuki D, Fujisawa Y, Matsushita A, Ishigami M, Ishiyama H, Hayakawa K

    Physics in medicine and biology   62 巻 ( 11 ) 頁: 4551-4570   2017年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1088/1361-6560/aa67cc

    PubMed

  32. Direct observation of DNA overwinding by reverse gyrase 招待有り 査読有り

    Taisaku Ogawa, Katsunori Yogo, Shou Furuike, Kazuo Sutoh, Akihiko Kikuchi, Kazuhiko Kinosita Jr

    Proceedings of the National Academy of Sciences of the United States of America   112 巻 ( 24 ) 頁: 7495   2015年6月

  33. Microfocus X-ray imaging of the internal geometry of brachytherapy seeds 招待有り 査読有り

    Tomoyuki Hasegawa , Takashi Hanada , Atsunori Yorozu , Hidetaka Ito , Shinji Masuda , Maki Kawahara , Katsunori Yogo , Kazushige Hayakawa

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine   86 巻   頁: 13 - 20   2014年4月

     詳細を見る

  34. Direct observation of strand passage by DNA-topoisomerase and its limited processivity 招待有り 査読有り

    Katsunori Yogo, Taisaku Ogawa, Masahito Hayashi, Yoshie Harada, Takayuki Nishizaka, Kazuhiko Kinosita Jr

    PloS one   7 巻 ( 4 ) 頁: e34920   2012年4月

     詳細を見る

    担当区分:筆頭著者  

  35. Electric quadrupole moment of B-17 and anomalous E2 effective charges for neutron-rich nuclei 招待有り 査読有り

    H Ogawa, K Asahi, K Sakai, T Suzuki, H Izumi, H Miyoshi, M Nagakura, K Yogo, A Goto, T Suga, T Honda, H Ueno, YX Watanabe, K Yoneda, A Yoshimi, N Fukuda, Y Kobayashi, A Yoshida, T Kubo, M Ishihara, N Imai, N Aoi, WD Schmidt-Ott, G Neyens, S Teughels

    PHYSICAL REVIEW C   67 巻 ( 6 )   2003年6月

  36. Nuclear spin maser with an artificial feedback mechanism 招待有り 査読有り

    A Yoshimi, K Asahi, K Sakai, M Tsuda, K Yogo, H Ogawa, T Suzuki, M Nagakura

    PHYSICS LETTERS A   304 巻 ( 1-2 ) 頁: 13 - 20   2002年11月

     詳細を見る

  37. Gamma-ray spectroscopy of Mg-34 via RI beam fragmentation 招待有り 査読有り

    K Yoneda, H Sakurai, T Gomi, T Motobayashi, N Aoi, N Fukuda, U Futakami, Z Gacsi, Y Higurashi, N Imai, N Iwasa, H Iwasaki, T Kubo, M Kunibu, M Kurokawa, Z Liu, T Minemura, A Saito, M Serata, S Shimoura, S Takeuchi, YX Watanabe, K Yamada, Y Yanagisawa, K Yogo, A Yoshida, M Ishihara

    NUCLEAR PHYSICS A   701 巻   頁: 437C - 440C   2002年4月

  38. Deformation of Mg-34 studied via in-beam gamma-ray spectroscopy using radioactive-ion projectile fragmentation 招待有り 査読有り

    K Yoneda, H Sakurai, T Gomi, T Motobayashi, N Aoi, N Fukuda, U Futakami, Z Gacsi, Y Higurashi, N Imai, N Iwasa, H Iwasaki, T Kubo, M Kunibu, M Kurokawa, Z Liu, T Minemura, A Saito, M Serata, S Shimoura, S Takeuchi, YX Watanabe, K Yamada, Y Yanagisawa, K Yogo, A Yoshida, M Ishihara

    PHYSICS LETTERS B   499 巻 ( 3-4 ) 頁: 233 - 237   2001年2月

  39. Quenching of neutron E2 effective charge in neutron-rich nuclei and the ground-state spin-parity of C-17 招待有り 査読有り

    H Ogawa, K Asahi, H Ueno, H Sakai, H Miyoshi, D Kameda, T Suzuki, H Izumi, N Imai, YX Watanabe, K Yoneda, N Fukuda, H Watanabe, A Yoshimi, W Sato, N Aoi, M Nagakura, T Suga, K Yogo, A Goto, T Honda, Y Kobayashi, WD Schmidt-Ott, G Neyens, S Teughels, A Yoshida, T Kubo, N Ishihara

    EUROPEAN PHYSICAL JOURNAL A   13 巻 ( 1-2 ) 頁: 81 - 85   2000年11月

▼全件表示

講演・口頭発表等 7

  1. 陽子線FLASH照射による水の発光のイメージング

    余語克紀ほか

    第83回応用物理学会秋季講演会  2022年9月22日 

     詳細を見る

    開催年月日: 2022年9月

  2. 金ナノ粒子の DNA への結合とがん治療用 X 線に対する放射線増感効果

    余語克紀ほか

    ナノ学会第20回大会  2022年5月20日 

     詳細を見る

    開催年月日: 2022年5月

  3. Luminescence imaging of water irradiated by proton under FLASH radiation therapy conditions

    余語克紀ほか

    第123回 日本医学物理学会学術大会  2022年4月17日 

     詳細を見る

    開催年月日: 2022年4月

  4. がん治療用X線によるDNA損傷に対する金ナノ粒子の放射線増感効果

    余語克紀ほか

    第69回応用物理学会 春季学術講演会  2022年3月23日 

     詳細を見る

    開催年月日: 2022年3月

  5. Radiosensitization effect of gold nanoparticles on plasmid DNA damage induced by therapeutic MV X-rays

    余語克紀ほか

    第3回CIBoGリトリート(第14回NAGOYAグローバルリトリート)  2022年2月19日 

  6. 放射線誘発の DNA 損傷を指標とした放射線防護剤・増感剤の探索

    余語克紀ほか

    広島大学 第3回 放射線災害・医科学研究拠点 ワークショップ  2022年2月8日 

  7. 重粒子線誘発のDNA損傷に対する アミノ酸誘導体の保護効果

    余語克紀

    第125回 日本医学物理学会学術大会  2023年4月 

▼全件表示

共同研究・競争的資金等の研究課題 12

  1. 産総研-名大アライアンス事業

    2023年7月 - 2025年3月

    国内共同研究  

  2. 第48回(2023年度)がんその他の悪性新生物研究助成金

    2023年4月 - 2024年3月

  3. 令和4 年度「NU 部局横断イノベーション創出プロジェクト」

    2022年5月 - 2023年3月

    名古屋大学 

  4. 第47回(2022年度)がんその他の悪性新生物研究助成金

    2022年4月 - 2023年3月

    公益財団法人 愛知県がん研究振興会 

  5. 多機能性・金ナノ粒子と高い線量率の放射線治療の併用によるがん貴金属ナノ療法の創出

    2022年3月

    2021年度 貴金属に関わる研究助成金 

  6. 医工連携による機能性・放射線ナノメディシンの開発への基盤構築

    2021年12月 - 2023年3月

    東海国立大学機構大学横断 研究推進プロジェクト 

  7. DNA標的型金ナノ粒子と高線量率の放射線治療併用によるがん細胞増感制御法の開発

    2021年4月 - 2023年3月

    公益財団法人 立松財団   特別研究助成 

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

  8. 放射線影響協会 研究奨励助成金

    2021年4月 - 2022年3月

      詳細を見る

    担当区分:研究代表者  資金種別:競争的資金

  9. 第46回(2021年度)がんその他の悪性新生物研究助成金

    2021年4月 - 2022年3月

    公益財団法人 愛知県がん研究振興会 

      詳細を見る

    担当区分:研究代表者 

  10. 金ナノ粒子併用プラズマ治療に向けた DNA 損傷の増強効果の検証

    2021年4月

    共同利用・共同研究申請 

  11. 産総研-名大アライアンス事業

    2019年7月 - 2021年3月

    国内共同研究 

  12. 広島大学放射線災害・医科学研究拠点の共同研究費

    2018年4月 - 現在

    国内共同研究 

▼全件表示

科研費 7

  1. チェレンコフ光閾値以下のエネルギーの放射線照射による水の発光現象の医療応用

    研究課題/研究課題番号:22H03019  2022年4月 - 2027年3月

    科学研究費助成事業  基盤研究(B)

    山本 誠一, 余語 克紀, 平野 祥之

      詳細を見る

    担当区分:研究分担者 

    申請者は最近、チェレンコフ光閾値以下のエネルギーの放射線照射により水が発光する現象を発見し画像化に成功したが、その発光中に紫外線を多量に含む可能性を見出した。この紫外線は、細胞中のデオキシリボ核酸(DNA)損傷を引き起こしていると予想する。この点を明らかにするために、260nm付近の紫外線領域まで測定可能な分光画像測定装置を開発する。また、この発光に含まれる紫外線でラジカルを発生させる放射線増感剤、および紫外線の影響を減らす放射線防護材の開発を行い、放射線照射による水の発光現象が生体に大きな影響を与えていることを間接的に証明するとともに、発見した水の発光現象の医療応用を進める。

  2. 高い線量率の放射線治療ビーム誘発光の生体での可視化

    研究課題/研究課題番号:21K07699  2021年4月 - 2024年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    余語 克紀, 歳藤 利行

      詳細を見る

    担当区分:研究代表者 

    配分額:4030000円 ( 直接経費:3100000円 、 間接経費:930000円 )

    がん放射線治療は高齢化が進むわが国で有効な治療法である。治療では放射線を当てるべき腫瘍と避けるべき正常組織が混在しており、どこにどれだけ当てるかが治療成否のカギとなる。したがって、治療中の放射線が患者にどれだけ当たっているか、つまり照射線量の分布を可視化し、即時に確認する方法が求められる。本研究では、治療中に、放射線誘発の発光から、リアルタイムに(生体の)線量分布を可視化し、線量分布に、治療計画とのずれがないか観測するシステムを開発する。

  3. 放射線照射による生体分子の損傷解析と放射線治療効果モデルへの応用

    研究課題/研究課題番号:18K07631  2018年4月 - 2021年3月

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    平野 祥之, 余語 克紀

      詳細を見る

    実験については、バイオ実験については専門外であるため、ゼロから環境を整えるのに時間を要したがDNAの電気泳動ができるようになった。研究の目的の一つとしてDNAの損傷をラマンスペクトルで特徴付けることだが、ある程度はすでに研究されており、複数の先行研究により、損傷とラマンスペクトルの関係を見つけることができた。当該研究では、まず切断箇所の様子が明確になっている制限酵素による切断のラマンスペクトルを確認しようと試みたがうまく観測できなかった。おそらく電気泳動で分離した後、該当箇所を取り出す際の手続きに問題があったと考えられる。バイオの専門家に改善策の教示を受ける予定である。またはマイクロチップ電気泳動を利用して分離後、直接分光器で観測する方法を検討している。
    一方シミュレーションについては、DNAの直接効果に加えOHラジカルによる間接効果のモデルを組み込み両方の効果を考慮した。さらに文献を参考にして酸素濃度を考慮したモデルをシミュレーションに取り入れ、DSB/SSB比について文献値とほぼ一致させることができた。これにより粒子種やLETの違いによる損傷具合の予測を調べることができる。しかしこのシミュレーションについても、多くのモデルパラメータがあり、パラメータの値の妥当性について検討しなければならない。平行して分子動力学計算をはじめたので、損傷したDNAがどのような形で安定するのかについて調べる予定である。こちらについては分子動力学の専門家の指導を受けて進めている。

  4. 放射線による水の発光を用いた放射線治療品質管理ツールの開発

    研究課題/研究課題番号:18K07679  2018年4月 - 2021年3月

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    余語 克紀, 前山 拓哉

      詳細を見る

    20-30歳代女性の子宮頸癌の発症率が増加している中、高線量率(HDR)小線源治療は副作用が少なく、集中して高い線量を投与できる優れたがん治療法である。治療では、米粒大の小さなγ線源をがんへ運び、線源の止まる位置と止まる時間を制御し線量を投与する。しかし、高い線量率のため、線源動作のエラーの見逃しから、誤照射事故が起きる可能性がある。線源動作のエラーが目で見て分かりやすい測定ツールがあれば、事故を未然に防ぐのに有用と考えられる。
    HDR小線源治療の進歩に伴い、治療の安全な実施を確保するための品質保証(QA)の重要性が高まっている。しかし、従来のQA法では時間がかかり、いくつかの異なる測定ツールを使用する必要がある。そこで、本研究の目的は、新たにチェレンコフ光の可視化に基づき、HDR小線源治療専用のシンプルなQAツールを開発することである。
    192Irγ線源によって照射された純水からの発光を、CCDカメラを使用して撮影し、投影画像を得た。前年度からの続きで、既存のカメラや光学系を用いても、撮影時間を長くすることで比較的良好な画質が得られた。本年度は、データを仕上げ、現段階のシステムを用いて実現可能なQAツールの提案を行った。提案したQAツールでは、一枚の投影画像を使用して、線量分布、線源強度、線源位置を同時に測定できるため、HDR小線源治療の迅速かつ簡単なQA法に適していると考えられる。以上の成果を論文として発表した。

  5. 蛍光ゲル線量計の開発

    2017年4月 - 2020年3月

    科学研究費補助金  基盤研究(C)

      詳細を見る

    担当区分:研究分担者 

  6. 転移制御を目指したがん細胞特異的な新規・金属ナノ粒子による放射線併用療法の創出

    2013年4月 - 2016年3月

    科学研究費補助金  若手研究(B)

      詳細を見る

    担当区分:研究代表者 

  7. 過去症例のCT及び3D線量分布変形手法による重複再照射許容性の定量的評価法の確立

    研究課題/研究課題番号:23591851  2011年4月 - 2013年3月

    科学研究費助成事業 基盤研究(C)  

      詳細を見る

    担当区分:研究分担者 

▼全件表示