Zhang Xin, Penagaricano Jose, Narayanasamy Ganesh, Corry Peter, Liu TianXiao, Sanjay Maraboyina, Paudel Nava, Morrill Steven
Radiation Oncology Department, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
Radiation Oncology Department, Houston Methodist Cancer Center, Sugar Land, TX, 77479, USA.
J Appl Clin Med Phys. 2017 Jan;18(1):178-185. doi: 10.1002/acm2.12032.
RaySearch RayStation Fallback (FB) planning module can generate an equivalent backup radiotherapy treatment plan facilitating treatment on other linear accelerators. FB plans were generated from the RayStation FB module by simulating the original plan target and organ at risk (OAR) dose distribution and delivered in various backup linear accelerators. In this study, helical tomotherapy (HT) backup plans used in Varian TrueBeam linear accelerator were generated with the RayStation FB module. About 30 patients, 10 with lung cancer, 10 with head and neck (HN) cancer, and 10 with prostate cancer, who were treated with HT, were included in this study. Intensity-modulated radiotherapy Fallback plans (FB-IMRT) were generated for all patients, and three-dimensional conformal radiotherapy Fallback plans (FB-3D) were only generated for lung cancer patients. Dosimetric comparison study evaluated FB plans based on dose coverage to 95% of the PTV volume (R), PTV mean dose (D), Paddick's conformity index (CI), and dose homogeneity index (HI). The evaluation results showed that all IMRT plans were statistically comparable between HT and FB-IMRT plans except that PTV HI was worse in prostate, and PTV R and HI were worse in HN multitarget plans for FB-IMRT plans. For 3D lung cancer plans, only the PTV R was statistically comparable between HT and FB-3D plans, PTV D was higher, and CI and HI were worse compared to HT plans. The FB plans using a TrueBeam linear accelerator generally offer better OAR sparing compared to HT plans for all the patients. In this study, all cases of FB-IMRT plans and 9/10 cases of FB-3D plans were clinically acceptable without further modification and optimization once the FB plans were generated. However, the statistical differences between HT and FB-IMRT/3D plans might not be of any clinically significant. One FB-3D plan failed to simulate the original plan without further optimization.
瑞思捷RayStation备用（FB）计划模块可生成等效的备用放射治疗计划，便于在其他直线加速器上进行治疗。FB计划是通过模拟原始计划的靶区和危及器官（OAR）剂量分布，由RayStation FB模块生成的，并在各种备用直线加速器上实施。在本研究中，使用RayStation FB模块生成了用于瓦里安TrueBeam直线加速器的螺旋断层放疗（HT）备用计划。本研究纳入了约30例接受HT治疗的患者，其中10例为肺癌患者，10例为头颈部（HN）癌患者，10例为前列腺癌患者。为所有患者生成了调强放疗备用计划（FB-IMRT），仅为肺癌患者生成了三维适形放疗备用计划（FB-3D）。剂量学比较研究基于对95%计划靶体积（R）的剂量覆盖、计划靶体积平均剂量（D）、帕迪克适形指数（CI）和剂量均匀性指数（HI）对FB计划进行评估。评估结果显示，除了前列腺癌中计划靶体积HI在FB-IMRT计划中更差，以及HN多靶区计划中FB-IMRT计划的计划靶体积R和HI更差外，所有调强放疗计划在HT和FB-IMRT计划之间在统计学上具有可比性。对于三维肺癌计划，只有计划靶体积R在HT和FB-3D计划之间在统计学上具有可比性，计划靶体积D更高，与HT计划相比，CI和HI更差。与HT计划相比，使用TrueBeam直线加速器的FB计划通常能更好地保护危及器官。在本研究中，一旦生成FB计划，所有FB-IMRT计划病例和9/10的FB-3D计划病例在临床上均可接受，无需进一步修改和优化。然而，HT与FB-IMRT/3D计划之间的统计学差异可能没有任何临床意义。一个FB-3D计划在没有进一步优化的情况下未能模拟原始计划。
