Development of thin film diamond membrane detector for precise dosimetry for heavy ion cancer therapy

• Project/Area Number: 18K11916
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: Gunma University
• Principal Investigator: Kada Wataru 群馬大学, 大学院理工学府, 准教授 (60589117)
• Co-Investigator(Kenkyū-buntansha): 酒井 真理 群馬大学, 大学院医学系研究科, 助教 (70727338)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000); Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2018: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: 重粒子線場 / 線量計測 / LET / 半導体検出器 / ダイヤモンド / 薄膜構造 / ワイドダイナミックレンジ / 電荷増幅効果 / 重粒子線

Outline of Final Research Achievements

In this study, we have realized a wide dynamic range radiation detector for heavy-ion cancer therapy utilizing a wide-bandgap semiconductor. The recent trend in radiation oncology tends to utilize carbon or heavier ionized particles with higher linear energy transfer (LET). This induces a limitation of current dosimetry at the field where only physical doses are evaluated by conventional ionization chambers. Our group had been developed a dosimeter using a diamond detector that enables us energy-dispersive dosimetry in the heavy-ion cancer treatment field. A thin-film diamond detector with a film thickness of fewer than 50 μm was developed and combined with an electronic circuit system developed for micro-dosimetry. Different LET distribution was successfully obtained by the newly developed diamond dosimeter, which also able to estimate the α and β parameters that are required for estimating the relative biological effects (RBE).

Academic Significance and Societal Importance of the Research Achievements

本研究で実現した、半導体プローブでは、線エネルギー付与(LET)の計測から生物学的効果比を各深度で評価することが可能となっており、既存の線量計では無視されている線質の違いによる治療効果への影響を評価する技術を粒子線治療分野に提供することとなった。今後、炭素線以外の粒子を併用するLETペインティング等の先進粒子線治療場における線量計測評価や、その生物影響、ならびに治療品質管理をより正確に実現する技術として、線量計測・校正技術といった放射線計測技術の高度化や、関連する様々な医学物理研究の発展を促進する波及効果が期待できる。

Research Products

• [Int'l Joint Research] ウーロンゴン大学(オーストラリア)
• [Int'l Joint Research] CEA(フランス)
• [Int'l Joint Research] University of Wollongog(オーストラリア)
• [Int'l Joint Research] CEA-Saclay(フランス)
• [Int'l Joint Research] CMRP, University of Wollongong(オーストラリア)
• [Int'l Joint Research] Le Centre CEA de Saclay(フランス)
• [Journal Article] PH-0045: Characterization of proton, carbon and silicon ion beams using scCVD diamond-based microdosimeter (2021)
  • Author(s): I.A. Zahradnik, M. Pomorski, L. Tran, W. Kada, L. De Marzi, D. Tromson, P. Barberet, Z. Pastuovic, J. Vohradsky, S. Salvador, L. Leterrier, Y. Prezado, T. Pourcher, J. Herault, A. Rosenfeld
  • Journal Title: Radiotherapy and Oncology Volume: 152 Pages: S14-S15
  • DOI: 10.1016/s0167-8140(21)00071-2
  • Int'l Joint Research
• [Journal Article] Development of wide-bandgap semiconductor-based dosimeter for LET distribution measurement in carbon therapy filed (2020)
  • Author(s): W Kada, K Ohsaki, Y Ohki, Y Yamazaki, T Makino, T Ohshima, A Mattsumura and M Sakai
  • Journal Title: Journal of Physics: Conference Series Volume: 1662 Issue: 1 Pages: 012015-012015
  • DOI: 10.1088/1742-6596/1662/1/012015
  • Open Access
• [Presentation] 炭素線がん治療場線量分布の高精度解析を目的としたSiC半導体線量計素子の開発 (2021)
  • Author(s): 栁澤理央、 加田渉、 横田凌、山口皐平、大崎晃平、酒井真理、松村彰彦、大島武、牧野高紘
  • Organizer: 研究会「放射線検出器とその応用」（第35回）
• [Presentation] Development of Wide-bandgap Semiconductor Based Dosimeter for LET Distribution measurement in Carbon Therapy Field (2020)
  • Author(s): Wataru Kada, Yuya Ohki, Kohei Ohsaki, Yuichi Yamazaki, Takahiro Makino, Takeshi Ohshima, Akihiko Mattsumura, Makoto Sakai, Tomihiro Kamiya
  • Organizer: International conferences of Mini- Micro- Nano- Dosimetry (MMND 2020) in conjunction with Innovation Technologies in Radiation Oncology (ITRO 2020)
  • Int'l Joint Research
• [Presentation] 重粒子線がん治療場での線量評価を目的としたSiC半導体検出器の開発 (2019)
  • Author(s): 加田 渉、大木 佑哉、大崎 晃平、山﨑 雄一、牧野 高紘、大島 武、松村 彰彦、酒井 真理、花泉 修
  • Organizer: 第66回応用物理学会春季学術講演会
• [Presentation] Development of Silicon-carbide Based Radiation Detector Utilized at Carbon Therapy Facility at GHMIC (2018)
  • Author(s): Yuya Oki, Kohei Osaki, Wataru Kada, Takahiro Makino, Shin-ichiro Sato, Yuichi Yamazaki, Takahiro Satoh, Takeshi Ohshima, Akihiko Matsumura, Makoto Sakai and Tomihiro Kamiya
  • Organizer: 14th International Workshop on Ionizing Radiation Monitoring (IWIRM)
  • Int'l Joint Research
• [Remarks] 研究室ホームページ
  • URL: http://www.el.gunma-u.ac.jp/~hana/