Kuga Noriyuki, Shirieda Katsutoshi, Sato Yuta, Shimotabira Haruhiko, Kurogi Yusuke, Jinnouchi Takashi
Department of Radiological Science, Faculty of Health Sciences, Junshin Gakuen University, Fukuoka, Japan.
Radiological Division, Department of Radiological, University of Miyazaki Hospital, University of Miyazaki, Miyazaki, Japan.
J Med Phys. 2022 Jan-Mar;47(1):79-85. doi: 10.4103/jmp.jmp_117_21. Epub 2022 Mar 31.
The purpose of he study was to reduce setup errors during intensity-modulated radiation therapy (IMRT) with an original knee fixation device (KFD) and evaluate the clinical target volume (CTV) coverage.
Participants were classified into two groups: knee flexion (KF) group ( = 16), wherein participants' knees were fixed in a flexed position using the proposed KFD during planning computed tomography, and knee extension group (KE; n = 15), wherein no KFD was used. We investigated the residual rotational errors and inter-fractional setup errors with or without KFD. Furthermore, inter-fractional margins were calculated using logistic regression analysis, and CTV coverage was evaluated.
The residual rotational errors in the yaw and roll directions ( < 0.02) and the inter-fractional error in the anterior-posterior (A-P) direction ( < 0.02) improved significantly in the KF group compared with the KE group. Repeatability was improved for the pitch direction. The inter-fractional margins were 6.68 mm and 4.87 mm in the A-P and superior-inferior (S-I) directions, respectively, in the KF group, representing reductions (mm) of 20.8% and 12.6% compared with the KE group, respectively. The odds ratios for CTV coverage in the KF group compared to the KE group were 2.76 ( < 0.001) and 1.74 ( < 0.05) in the A-P and S-I directions, respectively.
The IMRT fixation method using an original KFD improved the residual rotational error in the three directions and the inter-fractional error in the A-P direction, reduced the interfractional margins in the A-P, and S-I directions and improved CTV coverage. Our original KFD may be a useful fixation method during prostate IMRT.
本研究旨在使用一种原创的膝关节固定装置（KFD）减少调强放射治疗（IMRT）期间的摆位误差，并评估临床靶区（CTV）的覆盖情况。
参与者被分为两组：膝关节屈曲（KF）组（n = 16），在计划计算机断层扫描期间使用所提出的KFD将参与者的膝盖固定在屈曲位置；膝关节伸展组（KE；n = 15），未使用KFD。我们研究了使用或不使用KFD时的残余旋转误差和分次间摆位误差。此外，使用逻辑回归分析计算分次间边界，并评估CTV覆盖情况。
与KE组相比，KF组在偏航和滚动方向上的残余旋转误差（<0.02）以及前后（A-P）方向上的分次间误差（<0.02）有显著改善。俯仰方向的重复性也得到了提高。KF组在A-P和上下（S-I）方向上的分次间边界分别为6.68 mm和4.87 mm，与KE组相比分别减少了20.8%和12.6%。KF组与KE组相比，在A-P和S-I方向上CTV覆盖的优势比分别为2.76（<0.001）和1.74（<0.05）。
使用原创KFD的IMRT固定方法改善了三个方向上的残余旋转误差和A-P方向上的分次间误差，减少了A-P和S-I方向上的分次间边界，并改善了CTV覆盖。我们的原创KFD可能是前列腺IMRT期间一种有用的固定方法。
