Stereotactic MR-guided adaptive radiation therapy for peripheral lung tumors
Stereotactic MR-guided adaptive radiation therapy for peripheral lung tumors
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DOI：
10.1016/j.radonc.2019.10.013
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发表时间：
2020-03-01
影响因子：
5.7
通讯作者：
Senan, Suresh
中科院分区：
文献类型：
--
作者：
Finazzi, Tobias;Palacios, Miguel A.;Senan, Suresh
背景与目的：我们研究了使用立体定向MR引导的自适应放射治疗（SMART）的好处提供SABR在周围位于lung tumors.Methods和materials：23例患者（25周围肺肿瘤）进行SMART在3-8分数的MR直线加速器或钴-60系统。在每次分割之前，采集屏气MR扫描，然后根据当天的解剖结构进行床上计划调整。使用室内监护仪在连续MR引导下进行屏气门控输注。通过比较112“预测”计划，这是重新计算的解剖结构的一天的基线计划，与表上重新优化的plannes.Results：完整的SMART程序需要一个中位数为48和62分钟的MR直线加速器和钴-60系统，分别进行了研究表上适应的好处。中位SMART-PTV为9.5 cm（3）（范围：3.1-55.6）。在14例接受自由呼吸4DCT的患者中，SMART-PTV测量了53.7%（范围31.9-75.0）的PTV，这些PTV是使用运动包围内部靶体积方法生成的。床上适应性改善了PTV的处方剂量覆盖率，从预测计划的中位数92.1%提高到重新优化计划的95.0%，从而将输送>= 100戈伊（BED 10戈伊）的分次比例从90.2%提高到PTV的95%。使用MR引导的门控屏气SABR的输送导致靶体积显著小于基于ITV的方法的情况。虽然在桌上的适应确保输送消融剂量的所有部分，剂量学的好处是适度的，这表明，每日在线计划调整可能不会受益于大多数外周肺肿瘤患者。(C)2019 Elsevier B. V.版权所有。
Background and purpose: We studied the benefits of using stereotactic MR-guided adaptive radiation therapy (SMART) for delivery of SABR in peripherally located lung tumors.Methods and materials: Twenty-three patients (25 peripheral lung tumors) underwent SMART in 3-8 fractions on an MR Linac or Cobalt-60 system. Before each fraction, a breath-hold MR scan was acquired, followed by on-table plan adaptation based on the anatomy-of-the-day. Breath-hold gated delivery was performed under continuous MR-guidance using an in-room monitor. Benefits of on-table adaptation were studied by comparing 112 "predicted" plans, which are the baseline plans recalculated on the anatomy-of-the-day, with the on-table reoptimized plans.Results: The full SMART procedure took a median of 48 and 62 minutes on the MR Linac and Cobalt-60 system, respectively. Median SMART-PTVs were 9.5 cm(3) (range, 3.1-55.6). In 14 patients who had undergone a free-breathing 4DCT, SMART-PTVs measured 53.7% (range, 31.9-75.0) of PTVs that would have been generated using a motion-encompassing internal target volume approach. On-table adaptation improved prescription dose coverage of the PTV from a median of 92.1% in predicted plans, to 95.0% in reoptimized ones, thereby increasing the proportion of fractions delivering >= 100 Gy (BED10Gy) to 95% of PTV, from 90.2% to 100.0%.Conclusion: Delivery of gated breath-hold SABR using MR-guidance resulted in significantly smaller target volumes than would have been the case with an ITV-based approach. Although on-table adaptation ensured delivery of ablative doses in all fractions, the dosimetric benefits were modest, suggesting that daily online plan adaptation may not benefit most patients with peripheral lung tumors. (C) 2019 Elsevier B.V. All rights reserved.