Development of urinary adverse event prediction model in radiotherapy for prostate cancer

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K08129
• 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: Keio University
• Principal Investigator: OHASHI TOSHIO 慶應義塾大学, 医学部(信濃町), 准教授 (70327641)
• Co-Investigator(Kenkyū-buntansha): 深田 恭平 慶應義塾大学, 医学部(信濃町), 助教 (00647266) ; 田中 智樹 慶應義塾大学, 医学部(信濃町), 助教 (80594598)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 前立腺がん / 放射線治療 / 尿路 / 有害事象

Outline of Final Research Achievements

In external irradiation, the prostate and rectum are irradiated in multiple fractions, but the position of the prostate and rectum varies slightly with each irradiation, and this slight displacement each time affects the actual dose received by the patient. Especially in external irradiation combined with tissue internal irradiation, the placement of linear gold markers in the connective tissue on both sides of the prostate was effective for optimal image-guided radiation therapy without disturbing the placement of the seed source. It was known that the mechanical isocenters were displaced over time with the use of the linear accelerator, and it was proven that the displacement over time affected dose delivery from the time of commissioning. Regarding the analysis of predictors of adverse urinary tract events using deep learning, it was found that the model could not be constructed and further study is needed.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

本研究では、最適な画像誘導技術により尿道線量を低減させることができることが示された。とくに、組織内照射併用の外部照射では、シード線前立腺両外側の結合織内に線状金マーカーを留置する手法が有効だった。治療後の有害事象を少なくすることにより、個人のQOL向上が期待されるだけでなく、社会全体として医療経済の負担軽減に寄与できる可能性がある。