The Dosimetric Impact of Shifts in Patient Positioning during Boron Neutron Capture Therapy for Brain Tumors.
The Dosimetric Impact of Shifts in Patient Positioning during Boron Neutron Capture Therapy for Brain Tumors.
复制标题
DOI：
10.1155/2018/5826174
复制
发表时间：
2018
影响因子：
--
通讯作者：
Wu YH
中科院分区：
文献类型：
--
作者：
Lee JC;Chen YW;Chuang KS;Hsu FY;Chou FI;Hsu SM;Yen SH;Wu YH
与传统的光子放射治疗不同，复杂的患者定位工具不适用于硼中子捕获治疗（BNCT）。因此，BNCT仍然容易受到设置错误和部分内患者运动的影响。本研究的目的是评估在清华开放池式反应堆（THOR）的脑肿瘤的BNCT管理的剂量定位偏差的影响。对于这些研究，基于患有脑肿瘤的患者的计算机断层扫描（CT）图像生成模拟头部模型。在距离该头部模型的后部头皮6.5 cm和2.5 cm处（分别为T6.5cm和T2.5 cm），对直径3 cm和长度5 cm的圆柱形脑肿瘤进行建模。 对每个距离评价与定位误差相关的辐射剂量，包括左右移位、上级和下级移位、从射束孔径中心轴的移位以及从射束孔径表面向外移位。还评价了旋转和倾斜效应。剂量处方为20戈瑞当量（Gy-Eq）至80%的肿瘤。使用治疗计划系统NCTPlan进行剂量计算。与初始肿瘤位置的给药剂量相比，T6.5 cm的平均肿瘤剂量在左侧、右侧、上级和下侧组成的1 cm、2 cm和3 cm侧向位移中的平均降低分别约为1%、6%和11%。对于T6.5 cm，向外偏移1 cm、2 cm和3 cm的平均肿瘤剂量分别降低约5%、11%和15%。 对于T2.5 cm处的浅表肿瘤，在侧向移位1 cm后，未观察到平均肿瘤剂量显著降低。旋转和倾斜高达15°不会导致肿瘤剂量的显著差异。由于定位偏移而导致的正常组织的剂量差异也很小。综上所述，这些数据表明，在更大的深度给予肿瘤的平均剂量可能更容易受到定位偏差的影响，更大的移位距离导致THOR处的平均肿瘤剂量降低。此外，这些数据提供了对BNCT期间由设置误差或分次内运动引起的剂量差异的估计，并且这些数据可以促进对未来治疗中的实际患者剂量的更准确预测。
Unlike conventional photon radiotherapy, sophisticated patient positioning tools are not available for boron neutron capture therapy (BNCT). Thus, BNCT remains vulnerable to setup errors and intra-fractional patient motion. The aim of this study was to estimate the impact of deviations in positioning on the dose administered by BNCT for brain tumors at the Tsing Hua open-pool reactor (THOR). For these studies, a simulated head model was generated based on computed tomography (CT) images of a patient with a brain tumor. A cylindrical brain tumor 3 cm in diameter and 5 cm in length was modeled at distances of 6.5 cm and 2.5 cm from the posterior scalp of this head model (T6.5 cm and T2.5 cm, respectively). Radiation doses associated with positioning errors were evaluated for each distance, including left and right shifts, superior and inferior shifts, shifts from the central axis of the beam aperture, and outward shifts from the surface of the beam aperture. Rotational and tilting effects were also evaluated. The dose prescription was 20 Gray-equivalent (Gy-Eq) to 80 % of the tumor. The treatment planning system, NCTPlan, was used to perform dose calculations. The average decreases in mean tumor dose for T6.5 cm for the 1 cm, 2 cm, and 3 cm lateral shifts composed by left, right, superior, and inferior sides, were approximately 1 %, 6 %, and 11 %, respectively, compared to the dose administered to the initial tumor position. The decreases in mean tumor dose for T6.5 cm were approximately 5 %, 11 %, and 15 % for the 1 cm, 2 cm, and 3 cm outward shifts, respectively. For a superficial tumor at T2.5cm, no significant decrease in average mean tumor dose was observed following lateral shifts of 1 cm. Rotational and tilting up to 15° did not result in significant difference to the tumor dose. Dose differences to the normal tissues as a result of the shifts in positioning were also minimal. Taken together, these data demonstrate that the mean dose administered to tumors at greater depths is potentially more vulnerable to deviations in positioning, and greater shift distances resulted in reduced mean tumor doses at the THOR. Moreover, these data provide an estimation of dose differences that are caused by setup error or intra-fractional motion during BNCT, and these may facilitate more accurate predictions of actual patient dose in future treatments.
登录
查看更多内容
DOI：
10.1016/j.ijrobp.2016.02.028
发表时间：
2016-05-01
影响因子：
7
作者：
Wang, Ling-Wei;Chen, Yi-Wei;Yen, Sang-Hue
通讯作者：
Yen, Sang-Hue
影响因子：
2.2
作者：
Hu, JP;Reciniello, RN;Holden, NE
通讯作者：
Holden, NE
影响因子：
1.6
作者：
Liu, YWH;Huang, TT;Liu, HM
通讯作者：
Liu, HM
影响因子：
1.6
作者：
Hsu, F. Y.;Liu, M. T.;Chou, F. I.
通讯作者：
Chou, F. I.
影响因子：
48
作者：
Schneider CA;Rasband WS;Eliceiri KW
通讯作者：
Eliceiri KW