Jermoumi M, Korideck H, Bhagwat M, Zygmanski P, Makrigiogos G M, Berbeco R I, Cormack R C, Ngwa W
Department of Applied Physics, Medical Physics Program, University of Massachusetts at Lowell, MA, USA; Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute and Harvard Medical School, Boston, MA, USA.
Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute and Harvard Medical School, Boston, MA, USA.
Phys Med. 2015 Jul;31(5):529-35. doi: 10.1016/j.ejmp.2015.04.010. Epub 2015 May 8.
To develop and test the suitability and performance of a comprehensive quality assurance (QA) phantom for the Small Animal Radiation Research Platform (SARRP).
A QA phantom was developed for carrying out daily, monthly and annual QA tasks including: imaging, dosimetry and treatment planning system (TPS) performance evaluation of the SARRP. The QA phantom consists of 15 (60 × 60 × 5 mm(3)) kV-energy tissue equivalent solid water slabs. The phantom can incorporate optically stimulated luminescence dosimeters (OSLD), Mosfet or film. One slab, with inserts and another slab with hole patterns are particularly designed for image QA.
Output constancy measurement results showed daily variations within 3%. Using the Mosfet in phantom as target, results showed that the difference between TPS calculations and measurements was within 5%. Annual QA results for the Percentage depth dose (PDD) curves, lateral beam profiles, beam flatness and beam profile symmetry were found consistent with results obtained at commissioning. PDD curves obtained using film and OSLDs showed good agreement. Image QA was performed monthly, with image-quality parameters assessed in terms of CBCT image geometric accuracy, CT number accuracy, image spatial resolution, noise and image uniformity.
The results show that the developed QA phantom can be employed as a tool for comprehensive performance evaluation of the SARRP. The study provides a useful reference for development of a comprehensive quality assurance program for the SARRP and other similar small animal irradiators, with proposed tolerances and frequency of required tests.
开发并测试适用于小动物辐射研究平台（SARRP）的综合质量保证（QA）模体的适用性和性能。
开发了一种QA模体，用于执行每日、每月和每年的QA任务，包括：SARRP的成像、剂量测定和治疗计划系统（TPS）性能评估。该QA模体由15个（60×60×5 mm³）千伏能量组织等效固体水板组成。该模体可纳入光激励发光剂量计（OSLD）、金属氧化物半导体场效应晶体管（Mosfet）或胶片。其中一块带有插入物的板和另一块带有孔图案的板专门设计用于图像QA。
输出稳定性测量结果显示每日变化在3%以内。以模体内的Mosfet为靶标，结果表明TPS计算值与测量值之间的差异在5%以内。百分比深度剂量（PDD）曲线、侧向射野轮廓、射野平坦度和射野轮廓对称性的年度QA结果与调试时获得的结果一致。使用胶片和OSLD获得的PDD曲线显示出良好的一致性。每月进行图像QA，根据CBCT图像几何精度、CT值精度、图像空间分辨率、噪声和图像均匀性评估图像质量参数。
结果表明，所开发的QA模体可作为评估SARRP综合性能的工具。该研究为制定SARRP和其他类似小动物辐照器的综合质量保证计划提供了有用的参考，并提出了所需测试的公差和频率。
