新一代低能量直线加速器的调试和初步经验，具有先进的传输和成像功能。

Commissioning and early experience with a new-generation low-energy linear accelerator with advanced delivery and imaging functionalities.

机构信息

Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.

出版信息

Radiat Oncol. 2011 Sep 30;6:129. doi: 10.1186/1748-717X-6-129.

DOI:10.1186/1748-717X-6-129

PMID:21961830

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3197498/

Abstract

BACKGROUND

A new-generation low-energy linear accelerator (UNIQUE) was introduced in the clinical arena during 2009 by Varian Medical Systems. The world's first UNIQUE was installed at Oncology Institute of Southern Switzerland and put into clinical operation in June 2010. The aim of the present contribution was to report experience about its commissioning and first year results from clinical operation.

METHODS

Commissioning data, beam characteristics and the modeling into the treatment planning system were summarized. Imaging system of UNIQUE included a 2D-2D matching capability and tests were performed to identify system repositioning capability. Finally, since the system is capable of delivering volumetric modulated arc therapy with RapidArc, a summary of the tests performed for such modality to assess its performance in preclinical settings and during clinical usage was included.

RESULTS

Isocenter virtual diameter was measured as less than 0.2 mm. Observed accuracy of isocenter determination and repositioning for 2D-2D matching procedures in image guidance was <1.2 mm. Concerning reproducibility and stability over a period of 1 year, deviations from reference were found <0.3 ± 0.2% for linac output, <0.1% for homogeneity, similarly to symmetry. Rotational accuracy of the entire gantry-portal imager system showed a maximum deviation from nominal 0.0 of <1.2 mm. Pre treatment quality assurance of RapidArc plans resulted with a Gamma Agreement Index (fraction of points passing the gamma criteria) of 97.0 ± 1.6% on the first 182 arcs verified.

CONCLUSIONS

The results of the commissioning tests and of the first period of clinical operation, resulted meeting specifications and having good margins respect to tolerances. UNIQUE was put into operation for all delivery techniques; in particular, as shown by the pre-treatment quality assurance results, it enabled accurate and safe delivery of RapidArc plans.

摘要

背景

瓦里安医疗系统于 2009 年在临床领域推出了新一代低能量直线加速器（UNIQUE）。世界上第一台 UNIQUE 安装在瑞士南部肿瘤研究所，并于 2010 年 6 月投入临床使用。本研究旨在报告其调试和临床运行第一年的结果。

方法

总结了调试数据、束流特性和治疗计划系统建模。UNIQUE 的成像系统包括二维-二维配准能力，并进行了测试以确定系统重新定位能力。最后，由于该系统能够使用 RapidArc 进行容积调强弧形治疗，因此还包括了为评估其在临床前和临床使用中的性能而进行的此类模式测试的总结。

结果

等中心虚拟直径测量值小于 0.2mm。在图像引导的 2D-2D 匹配程序中，观察到的等中心确定和重新定位的精度<1.2mm。关于 1 年期间的重复性和稳定性，在 linac 输出方面发现与参考值的偏差<0.3±0.2%，在均匀性和对称性方面<0.1%。整个旋转机架-端口成像系统的旋转精度最大偏差为名义值的<1.2mm。对前 182 个经验证的 RapidArc 计划进行的预治疗质量保证结果显示，伽玛符合指数（符合伽玛标准的点分数）为 97.0±1.6%。