独立验算软件调强放疗质量控制可行性研究

目的 探讨使用独立验算软件IMsure进行调强放疗质量保证的准确性和可行性.方法 以直线加速器瓦里安600C/D为例,选取25例Eclipse治疗计划系统(TPS)计算的调强放疗(IMRT)计划,采用IMsure进行剂量计算验证,同时用Matrixx平面探测矩阵进行实际测量.对TPS、IMsure计算结果和Matrixx测量结果进行相互比较.结果 选取中心探头点作为参考点,IMsure计算结果和Matrixx测量结果与TPS计算结果偏差分别为(-0.11 ±1.24)％(t=0.20,P=0.840)和(-0.18 +1.45)％(t=0.86,P=0.400).3mm/3％和2mm/2％标准下IMsure对TPS计算结果的验证γ通过率分别为(98.7±2.8)％和(94.9±7.2)％,Matrixx对TPS计算结果的验证γ通过率分别为(99.0±2.0)％和(93.2±6.9)％,3 mm/3％标准下IMsure与Matrixx对TPS计算结果的验证γ通过率没有统计学差异(t =1.54,P=0.126).结论 IMsure可较好用于TPS初期的验收和临床测试.在常规临床放疗中通过IMsure对IMRT计划进行“预验证”,在充分常规放疗质量保证措施下可部分代替IMRT的实际测量验证,从而减轻日常的测量工作.

The feasibility study of independent check for intensity-modulated radiotherapy

Objective To investigate of the accuracy and feasibility of independent check for intensity-modulated radiotherapy (IMRT).Methods Inputing the linear accelerator Varian 600C/D physical data to IMsure ( a independent checking software) and constructing a calculation model.Use of IMsure to calculate the point dose and fluence of 25 cases IMRT treatment plans which have been calculated by Eclipse treatment planning system (TPS),and do a actual measurement of these plans by Matrixx at the same time.IMsure,TPS calculation results and measurement results of Matrixx were compared.Results Select Matrixx's center probe as a reference point,to TPS calculated results as the standard,then the average difference of the IMsure calculation and Matrixx measurement were ( -0.13 + 1.24)％ (t =0.20,P =0.840 ) and ( - 0.18 ± 1.45 ) ％ ( t =0.86,P =0.400 ),respectively.Compared IMsure with 3 mm/3 ％and 2 mm/2％ standard respectively,the average γ rate of TPS were (98.7 ±2.8)％ and (94.9 ±7.2)％ ;compared matrixx measurement results,the average γ rate of TPS were ( 99.0 + 2.0 ) ％ and ( 93.2 ±6.9) ％.The results show that the difference of the point dose and the γ rate of dose distribution by Matrixx measurement and IMsure calculation was no statistically significant difference ( t =1.54,P =0.126 ).Conclusions Independent checking software can be used in the treatment planning system to acceptance and initial clinical tests.In routine,a independent checking software as IMsure may do a" pre-verificaton" of IMRT treatment plan,or even partially replace of the actual measurement if the adequate conventional quality assurance do well,thus reducing the daily measurements.