PDF(Pubmed)
Abstract：
UNASSIGNED: Image-guided radiotherapy maximizes therapeutic index of brain irradiation by reducing setup errors during treatment. The aim of study was to analyze setup errors in the radiation treatment of glioblastoma multiforme and if decrease in planning target volume (PTV), margin is feasible using daily cone beam CT (CBCT) and 6D couch correction.
UNASSIGNED: Twenty-one patients (630 fractions of radiotherapy) were studied in which corrections were made in 6° of freedom. We determined setup errors, impact of setup errors of initial three fractions CBCT versus rest of the treatment with daily CBCT, and mean difference in setup errors with or without application of 6D couch and volumetric benefit of reduction of PTV margin from 0.5 cm to 0.3 cm.
UNASSIGNED: The mean shift in the conventional directions, namely, vertical, longitudinal, and lateral was 0.17 cm, 0.19 cm, and 0.11 cm. There was significant change in vertical shift when first three fractions were compared with rest of the treatment with daily CBCT. When the effect of 6D couch was nullified, all directions showed increased error with longitudinal shift being significant. The number of setup errors of magnitude >0.3 cm was more significant when only conventional shifts were applied as compared with 6D couch. There was significant decrease in volume of brain parenchyma irradiated when margin of PTV was reduced from 0.5 cm to 0.3 cm.
UNASSIGNED: Daily CBCT along with 6D couch correction can reduce setup error which allows reduction in PTV margin during radiotherapy planning in turn improving the therapeutic index.
UNASSIGNED: Twenty-one patients (630 fractions of radiotherapy) were studied in which corrections were made in 6° of freedom. We determined setup errors, impact of setup errors of initial three fractions CBCT versus rest of the treatment with daily CBCT, and mean difference in setup errors with or without application of 6D couch and volumetric benefit of reduction of PTV margin from 0.5 cm to 0.3 cm.
UNASSIGNED: The mean shift in the conventional directions, namely, vertical, longitudinal, and lateral was 0.17 cm, 0.19 cm, and 0.11 cm. There was significant change in vertical shift when first three fractions were compared with rest of the treatment with daily CBCT. When the effect of 6D couch was nullified, all directions showed increased error with longitudinal shift being significant. The number of setup errors of magnitude >0.3 cm was more significant when only conventional shifts were applied as compared with 6D couch. There was significant decrease in volume of brain parenchyma irradiated when margin of PTV was reduced from 0.5 cm to 0.3 cm.
UNASSIGNED: Daily CBCT along with 6D couch correction can reduce setup error which allows reduction in PTV margin during radiotherapy planning in turn improving the therapeutic index.
摘要：
UNASSIGNED：图像引导放射治疗通过减少治疗过程中的设置错误来最大化脑照射的治疗指数。研究的目的是分析多形性胶质母细胞瘤放射治疗中的设置错误，以及计划目标体积（PTV）是否减少，使用每日锥形束CT（CBCT）和6D床校正是可行的。
UNASSIGNED：研究了21名患者（630次放疗），其中在6°自由度进行了矫正。我们确定了设置错误，初始三个部分CBCT的设置误差与每日CBCT治疗的其余部分的影响，以及使用或不使用6D沙发的设置误差的平均差异，以及将PTV边缘从0.5cm减少到0.3cm的体积益处。
UNASSIGNED：常规方向的均值偏移，即,垂直,纵向,横向为0.17厘米，0.19厘米,和0.11厘米。当前三个部分与每日CBCT治疗的其余部分进行比较时，垂直偏移发生了显着变化。当6D沙发的效果无效时，所有方向均显示误差增加，纵向偏移显着。与6D沙发相比，当仅应用常规移位时，>0.3cm的设置误差的数量更为显着。当PTV的边缘从0.5cm减小到0.3cm时，照射的脑实质体积显着减少。
UNASSIGNED：每日CBCT与6D治疗床矫正可以减少设置误差，从而减少放疗计划期间的PTV边缘，进而改善治疗指数。
UNASSIGNED：研究了21名患者（630次放疗），其中在6°自由度进行了矫正。我们确定了设置错误，初始三个部分CBCT的设置误差与每日CBCT治疗的其余部分的影响，以及使用或不使用6D沙发的设置误差的平均差异，以及将PTV边缘从0.5cm减少到0.3cm的体积益处。
UNASSIGNED：常规方向的均值偏移，即,垂直,纵向,横向为0.17厘米，0.19厘米,和0.11厘米。当前三个部分与每日CBCT治疗的其余部分进行比较时，垂直偏移发生了显着变化。当6D沙发的效果无效时，所有方向均显示误差增加，纵向偏移显着。与6D沙发相比，当仅应用常规移位时，>0.3cm的设置误差的数量更为显着。当PTV的边缘从0.5cm减小到0.3cm时，照射的脑实质体积显着减少。
UNASSIGNED：每日CBCT与6D治疗床矫正可以减少设置误差，从而减少放疗计划期间的PTV边缘，进而改善治疗指数。
