Noninvasive monitoring of the intratumoral boron distribution using MRS in the neutron capture therapy

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K19239
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Medical Physics and Radiological Technology
• Research Institution: Kyorin University
• Principal Investigator: Sato Eisuke 杏林大学, 保健学部, 学内講師 (00439150)
• Research Collaborator: ISOBE Tomonori 筑波大学, 医学医療系, 教授 (70383643) ; YAMAMOTO Tetsuya 横浜市立大学, 医学部, 教授 (30375505) ; TADANO Kiichi 杏林大学, 保健学部, 助教 (20759443)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 中性子捕捉療法 / 非侵襲的モニタリング

Outline of Final Research Achievements

The treatment plan of the boron neutron capture therapy (BNCT) is devised on a premise that the intratumoral boron distribution is uniform. However, the intratumoral boron distribution is actually nonuniform. Therefore, the radiation dose to be given to the patients is not precise. The purpose of this study is to establish a method to evaluate boron distribution in tumors using a non-invasive MR system.
In this study, the simulated tumor phantom (PEG phantom) was developed by regulating a molecular weight and concentrations of the polyethylene glycol, and the characteristics (repeatability, reproducibility, change over time) were evaluated. As a result, the ADC values of the PEG phantom were equivalent to ADC values of various disease reported in the past. Furthermore, this study showed that we could acquire the ADC values with high precision.

Free Research Field

中性子捕捉療法，磁気共鳴画像

Academic Significance and Societal Importance of the Research Achievements

ホウ素中性子捕捉療法の治療効果は，腫瘍内のホウ素量とホウ素分布に依存する．ホウ素分布を高い精度で評価できない場合，がん治療に用いる放射線量が過剰もしくは過少に評価され，治療効果に影響が生じる．そのため，腫瘍内のホウ素分布を高い精度で評価する必要がある．MR装置は空間分解能が非常に高く，放射線を用いないため非侵襲的である．非侵襲的なMR装置を用いて腫瘍内ホウ素分布を高い精度で評価できれば，中性子捕捉療法の治療効果を高めることに加え，患者の被ばく低減につながる．本研究結果は，非侵襲的なMR装置を用いて腫瘍内ホウ素分布を高い精度で評価できる可能性を示唆している．