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  • [Radiat Oncol.] IMRT 치료계획의 변조도 평가

    [Radiat Oncol.] IMRT 치료계획의 변조도 평가 Assessment of the modulation degrees of intensity-modulated radiation therapy plans.

    서울의대 / 박소연, 박종민*

  • 출처
    Radiat Oncol.
  • 등재일
    2018 Dec 13
  • 저널이슈번호
    13(1):244. doi: 10.1186/s13014-018-1193-9.
  • 내용

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    Abstract
    BACKGROUND:
    To evaluate the modulation indices (MIs) for predicting the plan delivery accuracies of intensity-modulated radiation therapy (IMRT) plans.

    METHODS:
    A total of 100 dynamic IMRT plans that used TrueBeam STx and 102 dynamic IMRT plans that used Trilogy were selected. For each plan, various MIs were calculated, which included the modulation complexity score (MCS), plan-averaged beam area (PA), plan-averaged beam irregularity (PI), plan-averaged beam modulation (PM), MI quantifying multi-leaf collimator (MLC) speeds (MIs), MI quantifying MLC acceleration (MIa), and MI quantifying MLC acceleration and segment aperture irregularity (MIc,IMRT). To determine plan delivery accuracy, global gamma passing rates, MLC errors of log files, and dose-volumetric parameter differences between original and log file-reconstructed IMRT plans were obtained. To assess the ability of each MI for predicting plan delivery accuracy, Spearman's rank correlation coefficients (rs) between MIs and plan delivery accuracy measures were calculated.

    RESULTS:
    PI showed moderately strong correlations with gamma passing rates in MapCHECK2 measurements of both TrueBeam STx and Trilogy (rs = - 0.591 with p <  0.001 and - 0.427 with p <  0.001 to with gamma criterion of 2%/2 mm, respectively). For ArcCHECK measurements, PI also showed moderately strong correlations with the gamma passing rates in the ArcCHECK measurements of TrueBeam STx and Trilogy (rs = - 0.545 with p <  0.001 and rs = - 0.581 with p <  0.001 with gamma criterion of 2%/2 mm, respectively). The PI showed the second strongest correlation with MLC errors in both TrueBeam STx and Trilogy (rs = 0.861 with p <  0.001 and rs = 0.767 with p <  0.001, respectively). In general, the PI showed moderately strong correlations with every plan delivery accuracy measure.

    CONCLUSIONS:
    The PI showed moderately strong correlations with every plan delivery accuracy measure and therefore is a useful predictor of IMRT delivery accuracy.

     


    Author information

    Park SY1,2, Kim JI2,3,4, Chun M2,3,4, Ahn H2,3,4, Park JM5,6,7,8.
    1
    Department of Radiation Oncology, Veterans Health Service Medical Center, Seoul, Republic of Korea.
    2
    Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
    3
    Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.
    4
    Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
    5
    Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea. leodavinci@naver.com.
    6
    Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea. leodavinci@naver.com.
    7
    Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea. leodavinci@naver.com.
    8
    Institute for Smart System, Robotics Research Laboratory for Extreme Environments, Advanced Institutes of Convergence Technology, Suwon, Republic of Korea. leodavinci@naver.com.

  • 키워드
    Intensity-modulated radiation therapy; Modulation index; Plan delivery accuracy
  • 연구소개
    세기변조방사선치료계획의 변조 정도를 평가하는 다양한 변조 지표(modulation index)의 성능을 평가했습니다. 총 202개의 다양한 세기변조방사선치료계획에 대하여 기존에 제안된 다양한 변조지표를 구하고, 이를 기존 환자특이적 정도관리 결과와 상관분석을 수행했습니다. 다양한 변조지표 중, plan-averaged beam irregularity (PI)는 gamma passing rate (2%/2 mm)과 –0.591 (p < 0.001), MLC 위치오류와 0.861 (p < 0.001)의 상관계수를 보였습니다. PI는 기존의 다양한 환자특이적 정도관리 결과와 높은 상관관계를 고르게 보여, 세기변조방사선치료계획의 변조정도에 따른 치료 정확도를 예측하는 도구로 사용될 가능성을 보였습니다.
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