Development of Planning Target Volume Margin Automatic Determination System

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K16803
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 50020:Tumor diagnostics and therapeutics-related
• Research Institution: Kyushu University
• Principal Investigator: HIROSE Takaaki 九州大学, 大学病院, 診療放射線技師 (50608982)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: PTVマージン / 前立腺癌 / IMRT

Outline of Final Research Achievements

Observer uncertainty in CBCT registration of prostate cancer IMRT was evaluated. We investigated the uncertainty of registration in IGRT using CBCT images and the PTV margin considering inter-observer variability. We compared the uncertainty of prostate centroid registration in prostate cancer IGRT by 6 radiological technologists with the prostate contours extracted by radiation oncologists on CBCT images. It was classified into random errors and evaluated. The PTV margins to be considered due to inter-observer variability in IGRT were 3.5, 3.8, and 2.1 mm in the AP, SI, and LR directions, respectively.

Free Research Field

放射線治療

Academic Significance and Societal Importance of the Research Achievements

前立腺癌の画像誘導放射線治療における観察者間の変動を考慮した最適なPTVマージンの結果が得られた．PTVマージンは放射線治療の遂行にあたり，標的領域に十分な処方線量を投与するために，様々な不確かさを考慮して決定され，治療成績にも大きく寄与するものである．得られた結果は．局所腫瘍制御率の向上と正常組織障害の低減を可能とし，患者の「生活の質(Quality Of Life: QOL)」の向上に繋がる．