Total marrow irradiation as a conditioning therapy before allogeneic hematopoietic cell transplantation

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K16818
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: International University of Health and Welfare (2022-2023); The University of Tokyo (2020-2021)
• Principal Investigator: Takenaka Ryosuke 国際医療福祉大学, 国際医療福祉大学成田病院, 教授 (30823421)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 全身照射 / 強度変調放射線治療 / 造血幹細胞移植

Outline of Final Research Achievements

Hematopoietic stem cell transplantation is a radical treatment for many blood diseases. Before allogeneic hematopoietic stem cell transplantation, pretreatment with high-dose chemotherapy and whole-body irradiation is performed to prevent engraftment failure, but with whole-body irradiation, radiation damage caused by exposure to normal organs can sometimes be a serious problem. . The purpose of this study is to avoid radiation damage by irradiating only the entire bone marrow and lymphatic system, rather than irradiating the whole body, and to improve the prognosis after transplantation.
One year after transplantation, the overall survival rate was 81.8%, the recurrence-free survival rate was 54.0%, and the recurrence-free survival rate without adverse events was 42.0%. These are the results of whole body irradiation using conventional irradiation methods.
The results were comparable to those reported in the literature after transplantation.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

高齢者や有合併症症例におけるミニ移植でも、骨髄非破壊的前処置として従来施行されている4GyのTBIをTMLIに代えることで、有害事象を増やすことなく線量増加が可能となり、血液原疾患の予後を改善できる可能性がある。
さらに、若年女性においては、前処置としてTBIを行うと永久不妊がほぼ必発するが、TMLIにより卵巣への被曝を避けることで妊孕性の温存を図ることが可能となる。若年者が多い血液悪性疾患で、妊孕性を温存する治療と可能となれば、患者のQOLを飛躍的に向上できるだろう。