Valve Assi, Keyriläinen Jani, Kulmala Jarmo
Department of Medical Physics & Department of Oncology and Radiotherapy, Turku University Hospital, Hämeentie 11, FIN-20521 Turku, Finland.
Department of Medical Physics & Department of Oncology and Radiotherapy, Turku University Hospital, Hämeentie 11, FIN-20521 Turku, Finland.
Phys Med. 2017 Dec;44:42-50. doi: 10.1016/j.ejmp.2017.11.009. Epub 2017 Nov 21.
To use Compass as a model-based quality assurance (QA) tool for stereotactic body radiation therapy (SBRT) and stereotactic radiation therapy (SRT) volumetric modulated arc therapy (VMAT) treatment plans calculated with Eclipse treatment planning system (TPS).
Twenty clinical stereotactic VMAT SBRT and SRT treatment plans were blindly selected for evaluation. Those plans included four different treatment sites: prostate, brain, lung and body. The plans were evaluated against dose-volume histogram (DVH) parameters and 2D and 3D gamma analysis. The dose calculated with Eclipse treatment planning system (TPS) was compared to Compass calculated dose (CCD) and Compass reconstructed dose (CRD).
The maximum differences in mean dose of planning target volume (PTV) were 2.7 ± 1.0% between AAA and Acuros XB calculation algorithm TPS dose, -7.6 ± 3.5% between Eclipse TPS dose and CCD dose and -5.9 ± 3.7% between Eclipse TPS dose and CRD dose for both Eclipse calculation algorithms, respectively. 2D gamma analysis was not able to identify all the cases that 3D gamma analysis specified for further verification.
Compass is suitable for QA of SBRT and SRT treatment plans. However, the QA process should include wide set of DVH-based dose parameters and 3D gamma analysis should be the preferred method when performing clinical patient QA. The results suggest that the Compass should not be used for smaller field sizes than 3 × 3 cm or the beam model should be adjusted separately for both small (FS ≤ 3 cm) and large (FS > 3 cm) field sizes.
将Compass用作基于模型的质量保证（QA）工具，用于立体定向体部放射治疗（SBRT）以及使用Eclipse治疗计划系统（TPS）计算的立体定向放射治疗（SRT）容积调强弧形治疗（VMAT）治疗计划。
随机选取20个临床立体定向VMAT SBRT和SRT治疗计划进行评估。这些计划包括四个不同的治疗部位：前列腺、脑、肺和身体。根据剂量体积直方图（DVH）参数以及二维和三维伽马分析对计划进行评估。将Eclipse治疗计划系统（TPS）计算的剂量与Compass计算剂量（CCD）和Compass重建剂量（CRD）进行比较。
对于两种Eclipse计算算法，计划靶体积（PTV）平均剂量的最大差异分别为：AAA和Acuros XB计算算法TPS剂量之间为2.7±1.0%，Eclipse TPS剂量与CCD剂量之间为-7.6±3.5%，Eclipse TPS剂量与CRD剂量之间为-5.9±3.7%。二维伽马分析无法识别三维伽马分析指定需进一步验证的所有病例。
Compass适用于SBRT和SRT治疗计划的质量保证。然而，质量保证过程应包括广泛的基于DVH的剂量参数，并且在进行临床患者质量保证时，三维伽马分析应作为首选方法。结果表明，对于小于3×3 cm的射野尺寸不应使用Compass，或者对于小（FS≤3 cm）大（FS>3 cm）射野尺寸应分别调整射束模型。
