介绍了用IAEA法对Siemens primus E加速器输出剂量的计算、测量和校准程序,寻求准确、快捷、有效的测量方法。按IAEA规程确定各测量参数值,将吸收剂量计算公式化简成仪表读数乘以照射量校准因子Nx和温度、气压修正因子Ktp以及总校正因...介绍了用IAEA法对Siemens primus E加速器输出剂量的计算、测量和校准程序,寻求准确、快捷、有效的测量方法。按IAEA规程确定各测量参数值,将吸收剂量计算公式化简成仪表读数乘以照射量校准因子Nx和温度、气压修正因子Ktp以及总校正因子Cf的形式。通过对primus加速器的输出剂量测量并校准,使其精度符合质量保证和质量控制要求。此测量与校准方法,可以用于使用数字化医用加速器实施精确放疗对输出剂量的精度要求和临床治疗。展开更多
The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cr...The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cross calibration and relative array calibration were performed to enable absolute dose comparison. The linearity of response with dose and temperature sensitivity tests were also conducted to investigate dosimetric properties of the Delta4 device. The need to modify the original CT image of the Delta4 phantom for accurate dose calculation and comparison is addressed in this work, applying a CT extension algorithm. A number of test plans varying from simple 4—field conformal to IMRT and VMAT plans were measured to evaluate the accuracy of this device. It was found that the Delta4 device measured dose accurately to within ±1%. In order to maintain this level of accuracy the machine output fluctuations need to be corrected prior to each measurement and the relative array calibration needs to be performed every six months.展开更多
文摘介绍了用IAEA法对Siemens primus E加速器输出剂量的计算、测量和校准程序,寻求准确、快捷、有效的测量方法。按IAEA规程确定各测量参数值,将吸收剂量计算公式化简成仪表读数乘以照射量校准因子Nx和温度、气压修正因子Ktp以及总校正因子Cf的形式。通过对primus加速器的输出剂量测量并校准,使其精度符合质量保证和质量控制要求。此测量与校准方法,可以用于使用数字化医用加速器实施精确放疗对输出剂量的精度要求和临床治疗。
文摘The Delta4 3D dose verification device was commissioned in the current work for pre-treatment quality assurance (QA) of Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) plans. The cross calibration and relative array calibration were performed to enable absolute dose comparison. The linearity of response with dose and temperature sensitivity tests were also conducted to investigate dosimetric properties of the Delta4 device. The need to modify the original CT image of the Delta4 phantom for accurate dose calculation and comparison is addressed in this work, applying a CT extension algorithm. A number of test plans varying from simple 4—field conformal to IMRT and VMAT plans were measured to evaluate the accuracy of this device. It was found that the Delta4 device measured dose accurately to within ±1%. In order to maintain this level of accuracy the machine output fluctuations need to be corrected prior to each measurement and the relative array calibration needs to be performed every six months.
