Importance of deformable image registration and biological dose summation in planning of radiotherapy retreatments
Importance of deformable image registration and biological dose summation in planning of radiotherapy retreatments
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DOI：
10.1016/j.meddos.2017.06.006
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发表时间：
2017-12-01
影响因子：
1.2
通讯作者：
Lahtela, Sirpa-Liisa
中科院分区：
文献类型：
--
作者：
Boman, Eeva;Kapanen, Mika;Lahtela, Sirpa-Liisa
本研究的目的是评价非刚性和分割校正剂量总和对放疗总剂量的影响，并证明这种剂量总和对再治疗计划的临床决策的益处。研究了3例需要再次治疗相同部位（头颈部、脑和纵隔）的临床病例的风险器官（OAR）剂量总和。介绍并比较了新旧放射治疗计划的三种不同求和方法：（1）计划图像刚性配准和直接剂量求和的刚性原始求和;（2）可变形图像配准和直接剂量求和的可变形原始求和;（3）可变形配准的可变形生物求和，并考虑了某些关键器官中生物学方式的每部分剂量。在2种情况下，应用了用户定义的剂量缩减，以考虑治疗与辐射诱导效应愈合之间的时间。在列出的3种求和方法中，认为变形生物学求和提供了最合理的生物学解释。不同求和方法的近最大剂量（D0.1cc）曲线和剂量体积直方图（DVH）曲线有显著性差异。可变形原始总和和刚性原始总和D0.1 cc剂量之间的差异在-8戈伊至2戈伊范围内。同样，与刚性原始总和相比，可变形生物总和的偏差为-14戈伊至5戈伊。这些差异来自刚性原始总和情况下的剂量不正确总和，以及生物总和中的剂量/分数效应。我们的结论是，计算三维变形生物总和可能是一个有价值的工具，用于治疗复杂的再治疗患者。它有可能帮助肿瘤科医生改进最大治疗剂量的计划，同时尊重适当的组织耐受性。(C)2017年美国医学剂量学家协会。
The purpose of this study is to evaluate the effect of nonrigid and fractionation-corrected dose summation on total doses in radiotherapy and to demonstrate the benefits of such dose summation on clinical decision-making for planning of retreatments. Dose summation of organs at risk (OARs) was investigated for 3 clinical cases with need of retreatment to the same site: head and neck, brain, and mediastinum. Three different summation methods over old and new radiotherapy treatment plans are presented and compared: (1) rigid raw sum with rigid registration of the planning images and direct dose summing; (2) deformable raw sum with deformable image registration and direct dose summing; and (3) deformable biological sum with deformable registration and takes into account the dose per fraction in biological manner in certain critical organs. In 2 cases, a user-defined dose downscaling is applied to take into account the time between the treatments and the healing from the radiation-induced effects. Of the 3 summation methods presented, the deformable biological sum was considered to offer the most biologically plausible account of the treatment. There were remarkable differences between near-maximum doses (D0.1cc) and dose volume histogram (DVH) curves for OARs between different summation methods. The differences between deformable raw sum and rigid raw sum D0.1 cc doses are in the range from -8 Gy to 2 Gy. Similarly, the deviation was from -14 Gy to 5 Gy for the deformable biological sum compared with the rigid raw sum. These differences come from incorrect summation of doses in the rigid raw sum case, and from the dose per fraction effect in biological summation. We conclude that computing the 3-dimensional deformable biological summation could be a valuable tool for treating patients with complex retreatments. It has the potential to assist the oncologist in refining plans for maximally curative doses while respecting appropriate tissue tolerances. (C) 2017 American Association of Medical Dosimetrists.