Radiation dose from cone beam computed tomography for image-guided radiation therapy
Radiation dose from cone beam computed tomography for image-guided radiation therapy
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DOI：
10.1016/j.ijrobp.2007.08.062
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发表时间：
2008-01-01
影响因子：
7
通讯作者：
Lam, Nelson
中科院分区：
文献类型：
--
作者：
Kan, Monica W. K.;Leung, Lucullus H. T.;Lam, Nelson
目的：对三个不同治疗部位的锥形束计算机断层扫描 (CBCT) 的器官吸收剂量和有效剂量进行综合研究。方法和材料：使用广泛使用的 CBCT 系统机载成像仪 (OBI) 进行一系列广泛的剂量测量。使用带有热释光剂量计（TLD）的女性拟人体模进行测量。使用两种不同的技术设置，即标准模式和低剂量模式，报告了对身体的有效剂量和对26个器官的吸收剂量。对三个不同的扫描部位重复测量：头颈、胸部和骨盆。对标准模式CBCT、低剂量模式CBCT和扇形束CT之间的患者剂量和图像质量进行比较。结果：标准模式CBCT每次扫描对头颈部、胸部和骨盆的平均皮肤剂量分别为6.7、6.4和5.4 cGy。用于头颈部、胸部和骨盆成像的标准模式 CBCT 每次扫描对身体的有效剂量分别为 10.3、23.7 和 22.7 mSv。低剂量模式 CBCT 的患者剂量约为标准模式 CBCT 的五分之一。结论：OBI 每天获取的标准模式 CBCT 验证患者位置可能会使继发癌症风险增加高达 2% 至 4%。因此，应考虑每日 CBCT 的较低 mAs 设置，特别是当骨骼解剖学是主要兴趣时。 (C) 2008 爱思唯尔公司。
Purpose: To perform a comprehensive study on organ absorbed doses and effective doses from cone beam computed tomography (CBCT) for three different treatment sites.Methods and Materials: An extensive set of dosimetric measurements were performed using a widely used CBCT system, the On-Board Imager (OBI). Measurements were performed using a female anthropomorphic phantom with thermoluminescent dosimeters (TLD). The effective doses to the body and the absorbed doses to 26 organs were reported using two different technical settings, namely, the standard mode and the low-dose mode. The measurements were repeated for three different scan sites: head and neck, chest, and pelvis. Comparisons of patient doses as well as image quality were performed among the standard mode CBCT, low-dose mode CBCT, and fan beam CT.Results: The mean skin doses from standard mode CBCT to head and neck, chest and pelvis were 6.7, 6.4, and 5.4 cGy per scan, respectively. The effective doses to the body from standard mode CBCT for imaging of head and neck, chest, and pelvis were 10.3, 23.7, and 22.7 mSv per scan, respectively. Patient doses from low-dose mode CBCT were approximately one fifth of those from standard mode CBCT.Conclusions: Patient position verification by standard mode CBCTacquired by OBI on a daily basis could increase the secondary cancer risk by up to 2% to 4%. Therefore lower mAs settings for daily CBCT should be considered, especially when bony anatomy is the main interest. (C) 2008 Elsevier Inc.