多通道柱状施源器端到端测试

目的 确认多通道柱状施源器采用模板重建的参数设置,并完成投入临床使用前的端到端测试.方法 利用自制3D打印模体,多通道柱状施源器、CC13电离室和EBT3免洗胶片构建ETE模体.分别在施源器头尾两端设置靶区1和靶区2,完成处方剂量分别为5～7 Gy模拟计划设计并进行照射,获得实测点剂量及面剂量,与TPS剂量进行比较.以...

End-To-End Test of Multi-channel Cylinder Applicator

Objective To verify the reconstruction parameters of the multi-channel cylinder applicator from template,and to complete the end-to-end test before clinical use.Methods The 3D printed self-made phantom,multi-channel applicator,CC13 ionization chamber and EBT3 film was used to complete the ETE test.Target area 1 and target area 2 were set at both ends of the applicator,respectively,to complete the simulation plan design of the prescribed dose of 5~7 Gy and conduct irradiation,to obtain the measured point dose and surface dose,and compare with the TPS dose.The dose thresholds of 2 mm/2% and 10% were used as evaluation criteria,and the difference of plane dose distribution was analyzed by γ method.Results The reconstruction parameters of the multi-channel cylinder meet the nominal range.After the reconstruction using the TPS template,the parameters need to be partially changed.The tip length at the top of the central catheter is changed to 5.8 mm,and the surrounding catheters are changed to 4 mm,of which the source length is corrected to 1493 mm.The measurement deviation of ionization chamber was 0.97±0.32%,and the deviation of high dose area was smaller than that of low dose area.The results of the film dose analysis were in good agreement with the dose distribution of the TPS.The passing rate ofγin the sagittal plane was 97.4%,98.2% and 98.8%,in the horizontal plane was 99.3%,98.4% and 98.7%,respectively.The average passing rate ofγwas 98.5±0.63%.Conclusion Parameters of the new type of multi-channel cylinder applicator should be measured before clinical use and to adjust the parameters of the template accordingly.Through the ETE test,it is confirmed that the point dose and plane dose measurement results are satisfactory,which support the applicator for clinical use.