使用Compass验证系统对脑瘤VMAT计划的三维剂量学进行定量评估

Quantitative Evaluation of Three-dimensional Dosimetry for Brain Tumor VMAT Program using Compass Verification System

目的使用带有Dolphin探测器的Compass验证系统对脑瘤VMAT计划进行三维剂量验证,从而保证脑瘤放疗的剂量准确性以及临床更佳的剂量验证方案。方法选取20例在我院接受放射治疗的脑瘤患者,基于3%/2 mm评估标准,利用Compass独立计算和Dolphin实测重建结果比较靶区和危及器官的γ通过率。结果Compass独立计算结果显示,靶区γ通过率平均为94.92%、94.43%,危及器官γ通过率均在92%以上;Dolphin实测重建结果显示,靶区γ通过率平均为97.12%、96.67%,危及器官γ通过率则在93%以上。经证实二者均符合临床标准,但Dolphin实测重建结果优于Compass独立计算。结论在对脑瘤患者进行剂量验证时,尽管重建剂量结果优于独立计算结果,但是二者差异较小,基于三维剂量重建过程更加繁琐、耗时,临床上无法适用于所有患者,建议针对独立计算通过率较低的患者再进行实测,这样既能保证剂量准确性,又能减轻临床工作压力。

Objective To use the Compass verification system with Dolphin detector for three-dimensional dose verification of brain tumor VMAT plan,in order to ensure the accuracy of dose for brain tumor radiotherapy and a better clinical dose verification plan.Methods Selecting 20 brain tumor patients who received radiation therapy in our hospital,based on the 3%/2 mm evaluation standard,Compass independent calculation and Dolphin measured reconstruction results were used to compare the target area and organs at riskγpass rate.Results Compass independent calculation results display the averageγpassing rates of target area are 94.92%and 94.43%,the averageγpassing rates of organ at risk is above 92%;Dolphin measured reconstruction results show the averageγpassing rates of target area are 97.12%and 96.67%,the averageγpassing rates of organ at risk is above 93%.Research has found that both meet clinical standards,but Dolphin measured reconstruction results are better than Compass independent calculation.Conclusions When verifying the dose of brain tumor patients,although the reconstructed dose results are better than the independent calculation results,the difference between the two is relatively small.Based on the 3D dose reconstruction process,it is more cumbersome and time-consuming,and cannot be applied to all patients in clinical practice.This article suggests conducting further measurements for patients with lower independent calculation pass rates,which not only ensures dose accuracy but also reduces clinical work pressure.