Study on the development and application of three-dimensional dye gel dosimeters for radiation therapy

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K09072
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical Physics and Radiological Technology
• Research Institution: Hiroshima International University
• Principal Investigator: Hayashi Shin-ichiro 広島国際大学, 保健医療学部, 教授 (20238108)
• Co-Investigator(Kenkyū-buntansha): 高梨 宇宙 国立研究開発法人理化学研究所, 光量子工学研究センター, 研究員 (40646692) ; 川村 拓 国立研究開発法人理化学研究所, 創発物性科学研究センター, 客員研究員 (80424050)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 医学物理学 / 3次元ゲル線量計 / 光学CT / 放射線治療 / ラジオクロミック / 線量分布 / 品質保証 / 品質管理

Outline of Final Research Achievements

As a tool for directly evaluating the three-dimensional dose distribution in radiotherapy, we have developed a novel radiochromic gel (RG) dosimeter whose color tone changes with radiation. The RG dosimeter reported so far had practical inadequate points in terms of dose rate dependence and spatial/temporal resolution. The dosimeter that utilizes the color development by complex formation of iodine and polyvinyl alcohol developed by us in this study was able to significantly improve their characteristics. In particular, it has been shown that our system can be initialized, being used repeatedly. In addition, although optical CT is used to read the recorded dose distribution, it was found that ready-made optical CT is not sufficient. Along with that, we also performed to develop a dedicated optical CT at the same time.

Free Research Field

放射線化学，医学物理学，放射線計測学

Academic Significance and Societal Importance of the Research Achievements

3次元ラジオクロミックゲル（RG）線量計の開発は、これまで欧米の研究が先行していたが、我々の開発したRG線量計は既存のRG線量計とは異なる発色機構を用いており、国産のRG線量計である。また、既存のRG線量計のいくつかの欠点が改善されており、再利用可能である点も画期的である。また、光学CT装置は他の読み取り装置に比べて小型かつ安価で作製も容易なので、光学CTで線量評価可能な新規なRG線量計は、臨床での3次元ゲル線量計の実用化へも大きく前進させることができた。