Comprehensive research on individualized optimization of brain radiation therapy

2020 Fiscal Year Final Research Report

• Project/Area Number: 15H04903
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Radiation science
• Research Institution: Hokkaido University (2019-2020); Niigata University (2015-2018)
• Principal Investigator: Aoyama Hidefumi 北海道大学, 医学研究院, 教授 (80360915)
• Co-Investigator(Kenkyū-buntansha): 阿部 英輔 新潟大学, 医歯学系, 助教 (50571923) ; 稲川 正一 新潟大学, 医歯学系, 准教授 (60303567)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: 放射線腫瘍学 / 転移性脳腫瘍 / 放射線治療 / 認知機能

Outline of Final Research Achievements

The purpose of this study was to investigate a method for individual optimization of radiation therapy for patients with brain metastases. Through this research, a possibility was shown as follows; 1) the combined use of whole-brain radiation therapy (WBRT) with stereotactic irradiation (STI) may reduce the recurrence rate of brain tumors and improve the prognosis in a group of patients with an estimated prognosis of12 months or longer, 2) the cut-off value reflecting the clinically significant changes in neurocognitive function should be 1.5SD or higher in the international standardized neuro-cognitive battery, 3) the WBRT dose when combined with STI could be reduced from 30Gy-in-10 to 25Gy-in-10 without compromising brain tumor control and the reduction of dosage may improve the rate of preservation of neurocognitive function.

Free Research Field

放射線科学

Academic Significance and Societal Importance of the Research Achievements

本研究によって、近年発症頻度が高くなっている転移性脳腫瘍に対して、国際標準認知機能検査バッテリー日本語版の本邦で行われる臨床研究への導入が可能となり、また精密な予後の推定も可能とし、更に脳内の腫瘍制御を犠牲にせずに、認知機能の温存が可能な新たな全脳照射法が開発された。これらの結果から「予測予後に応じて治療法を個別化し、定位照射に併用する際の全脳照射の放射線量を低減し、腫瘍制御と認知機能を両立した転移性脳腫瘍に対する新たな放射線治療法の確立」に向け着実な進歩を遂げることができた。これらの点において、本研究は高い社会的意義を持つ。