Evaluation of Imaging Dose From Different Image Guided Systems During Head and Neck Radiotherapy: A Phantom Study

Abstract

This work evaluated and compared the absorbed doses to selected organs in the head and neck region from the three image guided radiotherapy systems: cone-beam computed tomography (CBCT) and kilovoltage (kV) planar imaging using the On-board Imager^® (OBI) as well as the ExacTrac^® X-ray system, all available on the Varian Novalis TX linear accelerator. The head and neck region of an anthropomorphic phantom was used to simulate patients’ head within the imaging field. Nanodots optically stimulated luminescent dosemeters were positioned at selected sites to measure the absorbed doses. CBCT was found to be delivering the highest dose to internal organs while OBI-2D gave the highest doses to the eye lenses. The setting of half-rotation in CBCT effectively reduces the dose to the eye lenses. Daily high-quality CBCT verification was found to increase the secondary cancer risk by 0.79%.

 

谷歌翻译的很好

这项工作评估和比较吸收的剂量从三个图像引导放射治疗系统：锥束计算机断层扫描（CBCT）和千伏（kV）平面成像使用板上成像（OBI）的头颈部区域选定的器官 以及ExacTrac®X射线系统，所有这些都可以在Varian Novalis TX线性加速器上使用。 使用人形体模的头部和颈部区域来模拟患者在成像视野内的头部。 将纳米点光学刺激的发光剂量计定位在选定的位置以测量吸收剂量。 发现CBCT向内脏递送最高剂量，而OBI-2D给眼睛晶状体提供最高剂量。 CBCT中的半旋转的设置有效地减少了对眼睛晶状体的剂量。 每日高质量的CBCT验证发现将继发性癌症风险增加0.79％。