Clinical and physical considerations in translational studies of intensity modulated radiation therapy

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K15572
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: National Cancer Center Japan
• Principal Investigator: Motegi Kana 国立研究開発法人国立がん研究センター, 東病院, 医学物理士 (40740436)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 頭頸部癌 / 強度変調放射線治療 / 治療計画

Outline of Final Research Achievements

In this study, a clinical evaluation was performed to introduce a robust treatment planning method for intensity modulated radiation therapy for head and neck cancer to prevent unnecessary irradiation of surrounding normal tissues while maintaining the prescribed dose to the clinical target volume even when patient positional uncertainty occurs. The dose distribution obtained using the robust treatment planning method was as robust as that obtained using conventional treatment planning method using the planned target volume against changes in the non-rigid deformation of body external and patient positional uncertainty during the treatment period. The dose to the parotid gland, a normal tissue that affects the patient's quality of life, can be reduced by a few Gy.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

治療計画の堅牢性の評価では、並進方向に故意に位置不確かさを発生させ、評価することが多いが、患者の位置不確かさには体内外の変形や回転も含まれる。本研究では、実治療に即した評価を行うべく、治療時の患者の様子を最も表しているCBCT画像からロバスト治療計画法の堅牢性を評価した。この点が他の研究と差別化でき、学術的意義となる。本研究の成果は、ロバスト治療計画を臨床に導入するための確かなエビデンスに直結するため、臨床での有用性が非常に高く、ロバスト治療計画法の臨床での早い実現が望まれる。