PTW729二维矩阵的平面剂量验证

Dosimetric Verification of PTW729 2D-Array

目的:调强计划在用于病人治疗之前必须要进行剂量学验证,以此确保调强计划各个射野出束剂量的精确度以及测量层面平面剂量分布的精确度。本文探讨逆向调强适形放射治疗过程中的剂量学验证,分析影响剂量验证结果的因素,采取相应措施消除影响,保证IMRT治疗计划临床实施的正确性。方法:选取30例需要做验证的调强计划,将计划移植至标准水模体上生成QA计划并在TPS上计算出测量平面的剂量分布,然后将计划导入MOSAIQ,ELEKTA Precise加速器执行QA计划,用PTW729二维电离室矩阵进行平面剂量验证,收集数据经矩阵扫描软件Matri Scan读出二维电离室矩阵收集的信息传递至Veri Soft软件中,对比剂量分布图得出计划通过率。结果:PTW729二维电离室矩阵能够测量照射野的剂量分布和强度分布,能够对逆向调强计划进行准确的剂量学验证,得出平面剂量验证的通过率与MLC叶片到位精准度和计划的子野面积有明确关系。结论 :利用PTW729二维电离室矩阵可以极大地简化验证工作量,提高验证的效率。

Objective To study the dosimetric verification of inverse intensity modulated conformal radiation therapy plan. Methods Firstly, 30 cases were selected to do verification intensity-modulated plan. Secondly, the plan was transplanted into a standard water phantom to generate QA plan and calculate the measurement plane on the TPS dose distribution. Thirdly, the plan was imported into MOSAIQ, ELEKTA Precise accelerator to execute QA plan. Fourthly, PTW729 two-dimensional ionization chamber array were used to do dose verification. Fitihly, matrix scanning software is used to get the information collected by PTW729, and then pass them to the VeriSoft sol, ware. By the steps above, the pass rate by contrasting dose distribution plans would be obtained. Results The PTW729 two-dimensional ionization chamber array could measure the dose distribution and intensity distribution of irradiation field, and perform accurate dosimetric verification for inverse intensity modulated plan. Conclusion With the PTW729 two-dimensional ionization chamber army, the workload of verification is lessened greatly and the efficiency of verification is improved.