二维半导体探测器阵列在调强放射治疗合成剂量验证中的应用

目的 利用一种二维半导体探测器阵列(2D-DA)对调强放射治疗(IMRT)进行多角度合成剂量验证,探索更真实地反映IMRT执行剂量分布精度的方法.方法 在2D-DA上附加等效水模体,对27例患者的IMRT计划分别进行单一机架角度合成(SGAC)和多机架角度合成(MGAC)的剂量分布验证测量,比较分析两种方法的测量结果....

The application of a 2D diode array in verifying the composite dose distribution of intensity modulated radiation therapy

Objective In order to explore the ways of reflecting the dose distribution in the implementation of the of IMRT (intensity modulated radiation therapy),a 2D diode array (2D-DA) was used in verifying the composite dose distribution of IMRT plans in the way of multi-gantry-angle composite (MGAC). Methods IMRT quality assure (QA) plans of 27 patients, based on the 2D-DA and solid water phantom, were designed and verified in two ways of single-gantry-angle composite (SGAC) and MGAC verifications. The comparison and analyzation of the dose distributions of the TPS calculation and the measurement of the 2D-DA were done. Results (1) When the beam central axes were not superposed with the detectors'plane of the 2D-DA, the verification passrate of SGAC and MGAC planar dose distribution of 27 patients'IMRT plan were 94.56%±4.28% and 94.81%±3.80% (the criteria: r value,3 mm/3%), respectively. There was no statistical difference between the results of two sets (t=-0.213, P >0.05). (2) When one of the beam central axes was superposed with the detectors'plane of the 2D-DA, the verification passrate of MGAC planar dose distribution were 79.72%±12.77%. Conclusions Using the 2D-DA with a proper phantom, there was no statistical difference in the SGAC and MGAC verifications of IMRT plans when the beam central axes were not superposed with the detectors'plane. However, the MGAC dose distribution can provide more about the clinical dosimetry, and the errors in the implementation of the of IMRT were easier located.