Development of a Dynamic Intensity-Modulated Radiation Therapy Planning Method Based on Multi-Objective Dose-Volume Constraints

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04080
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21030:Measurement engineering-related
• Research Institution: The University of Tokushima
• Principal Investigator: YOSHINAGA Tetsuya 徳島大学, 大学院医歯薬学研究部(医学域), 教授 (40220694)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 強度変調放射線治療計画 / 最適化問題 / 微分方程式 / 非線形問題

Outline of Final Research Achievements

Intensity-modulated radiation therapy is anticipated to become a more precise cancer treatment, offering high effectiveness with minimal side effects. We formulated a planning problem by separating mandatory dose-volume constraints and desirable constraints that we aim to meet as closely as possible. We developed an optimization method to address multiple constraints. Software compatible with three-dimensional imaging was created, and its utility was verified through clinical trials. As an application example, we proposed an approach that allows for dose reduction to the OAR (organs at risk) while meeting mandatory constraints, specifically targeting high-precision plans where some dose constraints are unmanageable. Additionally, we designed a method to efficiently solve problems where the PTV (planning target volume) and OAR regions overlap.

Free Research Field

医用工学

Academic Significance and Societal Importance of the Research Achievements

先行研究において，線量体積制約を満たす反復解への収束が理論的に保証された力学系を用いる独自の治療計画法を考案している．さらに，一部の線量制約が許容できない精度の高い治療計画が要求される困難な問題に対し，必須の制約条件と望ましい条件に分離して最適化問題を定式化し，解決法の開発にも成功した．ただし，条件を複数に与えると高精度な治療計画を効率的に実現できるが先行法では解決できなかった．本研究により，腫瘍組織に高い線量を正確に照射し，正常組織にはより少ない線量に抑える設計の枠組み構築と効率的な演算を可能とし，患者への治療効果を高めると同時に副作用を軽減できる治療計画の新しい方法を開発することができた．