期刊
MEDICAL PHYSICS
卷 37, 期 9, 页码 4620-4626出版社
WILEY
DOI: 10.1118/1.3476459
关键词
image guided radiation therapy; patient dose; cone-beam computed tomography; point dosimeter
资金
- U.S. Department of Energy [DE-GF07-05ID14700]
- Center for Disease Control/TKC Integration Services [TKC 30-07 185-01]
Purpose: The purpose of this study was to develop a practical method for estimating organ doses from kilovoltage cone-beam CT (CBCT) that can be performed with readily available phantoms and dosimeters. The accuracy of organ dose estimates made using the ImPACT patient dose calculator was also evaluated. Methods: A 100 mm pencil chamber and standard CT dose index (CTDI) phantoms were used to measure the cone-beam dose index (CBDI). A weighted CBDI (CBDIw) was then calculated from these measurements to represent the average volumetric dose in the CTDI phantom. By comparing CBDIw to the previously published organ doses, organ dose conversion coefficients were developed. The measured CBDI values were also used as inputs for the ImPACT calculator to estimate organ doses. All CBDI dose measurements were performed on both the Elekta XVI and Varian OBI at three clinically relevant locations: Head, chest, and pelvis. Results: The head, chest, and pelvis protocols yielded CBDIw values of 0.98, 16.62, and 24.13 mGy for the XVI system and 5.17, 6.14, and 21.57 mGy for the OBI system, respectively. Organ doses estimated with the ImPACT CT dose calculator showed a large range of variation from the previously measured organ doses, demonstrating its limitations for use with CBCT. Conclusions: The organ dose conversion coefficients developed in this work relate CBDIw values to organ doses previously measured using the same clinical protocols. Ultimately, these coefficients will allow for the quick estimation of organ doses from routine measurements performed using standard CTDI phantoms and pencil chambers. (c) 2010 American Association of Physicists in Medicine. [DOI: 10.1118/1.3476459]
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据