Development of real-time in vivo dose monitoring system using high energy therapeutic photons

• Project/Area Number: 16K01405
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical systems
• Research Institution: University of Tsukuba (2016, 2018); National Institutes for Quantum and Radiological Science and Technology (2017)
• Principal Investigator: Takei Hideyuki 筑波大学, 医学医療系, 助教 (20645452)
• Co-Investigator(Kenkyū-buntansha): 櫻井 英幸 筑波大学, 医学医療系, 教授 (50235222) ; 榮 武二 筑波大学, 医学医療系, 教授 (60162278) ; 磯辺 智範 筑波大学, 医学医療系, 教授 (70383643) ; 渡邉 祐介 北里大学, 医療衛生学部, 助教 (90582742)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 放射線治療 / X線 / 線量分布検証 / EPID / モンテカルロシミュレーション / 線量分布再構成 / CT画像上の線量計算 / 線量計算効率化 / 精度検証 / 3次元線量分布表示 / システム構築 / 基礎特性取得 / 画像診断システム

Outline of Final Research Achievements

In vivo dose verification during radiation therapy is necessary to confirm that the beam is irradiated as planned. This study developed a tool for in vivo dosimetry during a photon therapy using electronic portal imaging device (EPID) with high accuracy. A primary photon beam was reconstructed from an EPID image and the dose distribution in a phantom was calculated using Monte Carlo simulation.
The calculated dose agreed with the measured dose within 2% and 5% in the soft tissue and in the center of the lung, respectively.

Academic Significance and Societal Importance of the Research Achievements

放射線治療中に投与された体内線量を検証するシステムを開発した。治療計画通りに線量が投与されていることを確認し、位置ずれなどにより正しく線量投与されていない場合には、治療期間中に対策を講じることが可能となるため治療成績の向上が期待できる。本システムは、既に一般的な施設に広く使用されている装置を活用するため、新たに装置を導入する必要がない。この装置は体外で使用するものであるため侵襲性がなく、被ばく量が増えることもないため普及への支障が少ない。

Research Products

• [Journal Article] Development of Accurate EPID in Vivo Dosimetry for Photon Therapy (2018)
  • Author(s): Takei H, Isobe T, Watanabe Y, Hasegawa T, Sato E, Hara H, Muraishi H, Sakae T
  • Journal Title: Medical Physics Volume: 45 Pages: 278-278
• [Journal Article] General ion recombination effect in a liquid ionization chamber in high-dose-rate pulsed photon and electron beams (2018)
  • Author(s): Takei Hideyuki、Isobe Tomonori、Kitamura Nozomi、Mori Yutaro、Tomita Tetsuya、Kobayashi Daisuke、Kamizawa Satoshi、Sato Tomoharu、Sakurai Hideyuki、Sakae Takeji
  • Journal Title: Journal of Radiation Research Volume: 1 Issue: 3 Pages: 1-4
  • DOI: 10.1093/jrr/rrx088
  • NAID: 120007134046
  • Peer Reviewed / Open Access
• [Presentation] Development of Accurate EPID in Vivo Dosimetry for Photon Therapy (2018)
  • Author(s): Takei H, Isobe T, Watanabe Y, Hasegawa T, Sato E, Hara H, Muraishi H, Sakae T
  • Organizer: 60th Annual Meeting of the American Association of Physicists in Medicine
  • Int'l Joint Research
• [Presentation] Energy response correction for EPID dosimetry in photon radiation therapy (2017)
  • Author(s): Hideyuki Takei, Tomonori Isobe, Yusuke Watanabe, Tomoyuki Hasegawa, Eisuke Sato, Hidetake Hara, Hiroshi Muraishi, Takeji Sakae
  • Organizer: International Conference on Monte Carlo Techniques for Medical Applications
  • Int'l Joint Research