Ślosarek Krzysztof, Brąclik Iwona, Leszczyński Wojciech, Kopczyńska Joanna, Osewski Wojciech, Wendykier Jacek
Radiotherapy Planning Department, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology Gliwice Branch, Wybrzeże Armii Krajowej 15, 44-100 Gliwice, Poland.
IT Department, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology Gliwice Branch, Wybrzeże Armii Krajowej 15, 44-100 Gliwice, Poland.
Rep Pract Oncol Radiother. 2019 Jan-Feb;24(1):20-27. doi: 10.1016/j.rpor.2018.09.001. Epub 2018 Oct 10.
The aim of this study is to answer the question whether the calculated dose distributions for HD and Millennium collimators (Varian Medical Systems) are equivalent for large treatment volumes.
Modern biomedical linacs are equipped with multileaf collimators where leaves can be of different widths. Thinner leaves allow better fit to desired (tumor) shape. At the same time, however, the maximum size of the field that can be obtained with the collimator is also reduced. Varian Medical Systems HD and Millennium collimators can be a good sample. They have 40 cm or 22 cm × 40 cm maximal field size at the isocenter, respectively.
This paper presents the comparison of selected statistical and dosimetric parameters achieved for treatment plans where the beams for a HD collimator had to be merged because of the size of the tumor volume.
Achieved results show that, independently from irradiated volume, there is no statistically significant difference for calculated dose distributions, integral doses, MU values and coefficients evaluating dose distributions for HD and Millennium collimators.
Results show that both types of collimators can be used interchangeably for preparing the treatment plans for large tumor volume without quality reduction of the prepared treatment plan.
本研究旨在回答对于大治疗体积而言，瓦里安医疗系统公司的HD准直器和 Millennium 准直器的计算剂量分布是否等效这一问题。
现代生物医学直线加速器配备有多叶准直器，其中叶片宽度可以不同。较薄的叶片能更好地拟合期望的（肿瘤）形状。然而，与此同时，使用准直器可获得的最大射野尺寸也会减小。瓦里安医疗系统公司的HD准直器和 Millennium 准直器可以作为一个很好的样本。它们在等中心处的最大射野尺寸分别为40 cm或22 cm×40 cm。
本文展示了对因肿瘤体积大小而必须合并HD准直器射束的治疗计划所获得的选定统计和剂量学参数的比较。
所获得的结果表明，无论照射体积如何，HD准直器和 Millennium 准直器的计算剂量分布、积分剂量、MU值以及评估剂量分布的系数均无统计学显著差异。
结果表明，在为大肿瘤体积准备治疗计划时，这两种类型的准直器可以互换使用，而不会降低所准备治疗计划的质量。
