Feasibility of synchronization of real-time tumor-tracking radiotherapy and intensity-modulated radiotherapy from viewpoint of excessive dose from fluoroscopy
Feasibility of synchronization of real-time tumor-tracking radiotherapy and intensity-modulated radiotherapy from viewpoint of excessive dose from fluoroscopy
复制标题
DOI：
10.1016/j.ijrobp.2004.04.028
复制
发表时间：
2004-09-01
影响因子：
7
通讯作者：
Miyasaka, K
中科院分区：
文献类型：
--
作者：
Shirato, H;Oita, M;Miyasaka, K
目的：实时肿瘤跟踪放射治疗（RTRT）和调强放射治疗（IMRT）中的同步技术有望用于治疗运动中的肿瘤。我们的目标是从使用荧光透视导致过量剂量的角度来估计同步的可行性。方法和材料：使用诊断X射线电离室，我们测量了空气比释动能率、反向散射的表面剂量和剂量分布。来自荧光透视RTRT系统的固体体模中的深度分布。一个标称50-120千伏峰值（kVp）的X射线能量和一个标称1-4毫秒的脉冲宽度被用于measurement.Results：平均+/- SD空气比释动能率从一个荧光镜为238.8 +/- 0.54 mGy/h的标称脉冲宽度为2.0毫秒和标称100 kVp的X射线能量在等中心的直线加速器。空气比释动能率随X射线束能量的增加而急剧增加。表面剂量为28-980 mGy/h。体模中5.0 cm深度处的吸收剂量为峰值剂量的37-58%。估计皮肤表面剂量从一个荧光镜在RTRT为29-1182 mGy/h，强烈依赖于千伏峰值和脉冲宽度的荧光镜和轻微依赖于皮肤之间的距离和isocent.Conclusion：皮肤表面剂量和吸收的深度剂量导致透视在RTRT可以是显着的，如果RTRT是同步的IMRT使用多叶准直器。必须精确估计RT期间荧光透视的吸收剂量，并采取措施减少照射量。(C)2004年爱思唯尔公司
Purpose: Synchronization of the techniques in real-time tumor-tracking radiotherapy (RTRT) and intensity-modulated RT (IMRT) is expected to be useful for the treatment of tumors in motion. Our goal was to estimate the feasibility of the synchronization from the viewpoint of excessive dose resulting from the use of fluoroscopy.Methods and Materials: Using an ionization chamber for diagnostic X-rays, we measured the air kerma rate, surface dose with backscatter, and dose distribution in depth in a solid phantom from a fluoroscopic RTRT system. A nominal 50-120 kilovoltage peak (kVp) of X-ray energy and a nominal 1-4 ms of pulse width were used in the measurements.Results: The mean +/- SD air kerma rate from one fluoroscope was 238.8 +/- 0.54 mGy/h for a nominal pulse width of 2.0 ms and nominal 100 kVp of X-ray energy at the isocenter of the linear accelerator. The air kerma rate increased steeply with the increase in the X-ray beam energy. The surface dose was 28-980 mGy/h. The absorbed dose at a 5.0-cm depth in the phantom was 37-58% of the peak dose. The estimated skin surface dose from one fluoroscope in RTRT was 29-1182 mGy/h and was strongly dependent on the kilovoltage peak and pulse width of the fluoroscope and slightly dependent on the distance between the skin and isocenter.Conclusion: The skin surface dose and absorbed depth dose resulting from fluoroscopy during RTRT can be significant if RTRT is synchronized with IMRT using a multileaf collimator. Precise estimation of the absorbed dose from fluoroscopy during RT and approaches to reduce the amount of exposure are mandatory. (C) 2004 Elsevier Inc.