Radiation Oncology Centers (ROC), Radiological Associates of Sacramento (RAS), Sacramento, CA 95815, USA.
Med Phys. 2012 Jun;39(6):3051-9. doi: 10.1118/1.4711755.
To investigate using 3D γ analysis for IMRT and VMAT QA.
We explored and studied 3D γ-analysis by comparing TPS computed and EPID back-projection reconstructed doses in patient's CT images. Two 3D γ quantities, γ(PTV) and γ(10), were proposed and studied for evaluating the QA results, and compared to 2D γ (MapCheck composite: γ(MC)).
It was found that when 3%(global)/3 mm criteria was used, all IMRT and 90% of VMAT plans passed QA with a γ pass rate ≥90%. A significant statistical correlation was observed between 3D and 2D γ-analysis results for IMRT QA if γ(10) and γ(MC) are concerned, but no significant relation is found between γ(PTV) and γ(MC).
3D γ analysis based on EPID dose back-projection may provide a feasible tool for IMRT and VMAT pretreatment plan QA.
研究使用 3D γ 分析进行 IMRT 和 VMAT 的 QA。
我们通过比较患者 CT 图像中 TPS 计算和 EPID 反向投影重建剂量，探索和研究了 3D γ 分析。提出并研究了两个 3D γ 量，γ（PTV）和 γ（10），以评估 QA 结果，并与 2D γ（MapCheck 复合：γ（MC））进行比较。
发现当使用 3%（全局）/3mm 标准时，所有的 IMRT 和 90%的 VMAT 计划都通过了 QA，γ 通过率≥90%。如果考虑 γ（10）和 γ（MC），则 3D 和 2D γ 分析结果之间存在显著的统计学相关性，但 γ（PTV）和 γ（MC）之间没有发现显著关系。
基于 EPID 剂量反向投影的 3D γ 分析可为 IMRT 和 VMAT 预处理计划 QA 提供一种可行的工具。
