Imaging Cherenkov emission for quality assurance of radiation therapy

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K07679
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Nagoya University
• Principal Investigator: Yogo Katsunori 名古屋大学, 医学系研究科(保健), 助教 (30424823)
• Co-Investigator(Kenkyū-buntansha): 前山 拓哉 北里大学, 理学部, 助教 (70612125)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 放射線治療 / チェレンコフ光 / 高線量率小線源治療 / 品質保証 / 線源位置測定

Outline of Final Research Achievements

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. The light emission from plastic applicators, irradiated by an 192Ir γ-ray source, was captured using a charge-coupled device camera. We attached plastics to a metal applicator, to use as screens for the Cherenkov imaging.
We determined the source positions and dwell intervals from the light profiles and compared these with preset values and dummy marker measurements. The source positions and dwell intervals measured from the light images were comparable to the dummy marker measurements and preset values. The proposed method should be suitable for rapid and easy quality assurance (QA) investigations in HDR brachytherapy. The method allows for real-time, filmless measurements of the source positions to be obtained and is useful for rapid feedback in QA procedures.

Free Research Field

医学物理

Academic Significance and Societal Importance of the Research Achievements

高線量率小線源治療の品質保証は、従来、時間がかかり、煩雑であったが、この方法により、迅速かつ簡便に行うことが可能になった。線源動作エラーを未然に発見することで、さらに、安全ながん放射線治療に寄与すると期待される。放射線による治療器具の発光を、広くがん放射線治療の品質保証法に適用できる可能性を示すことができるため、さらなる応用が期待される。