Advantages and limitations of navigation-based multicriteria optimization (MCO) for localized prostate cancer IMRT planning
Advantages and limitations of navigation-based multicriteria optimization (MCO) for localized prostate cancer IMRT planning
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DOI：
10.1016/j.meddos.2014.02.002
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发表时间：
2014-09-01
影响因子：
1.2
通讯作者：
Hounsell, Alan R.
中科院分区：
文献类型：
--
作者：
McGarry, Conor K.;Bokrantz, Rasmus;Hounsell, Alan R.
对于先进的放射治疗技术来说，反向计划的功效变得越来越重要。本研究的目的是验证RayStation（v2.4，RaySearch Laboratories，Sweden）中的多标准优化（MCO）与Oncentra（v4.1，Nucletron BV，the Netherlands）中的标准调强放射治疗（IMRT）优化，并表征由于导航MCO计划转换为可输送的多叶准直器孔径而导致的剂量差异。使用标准优化和MCO为10例局限性前列腺癌患者创建了步进式调强放射治疗计划。选择具有最小平均直肠剂量的可接受标准IMRT计划与可交付MCO计划进行比较。对于MCO计划，通过允许在基于通量的计划之间进行连续导航的用户界面来管理权衡。导航MCO计划可沿着最大靶均匀性和最大直肠保留之间的轨迹以增量步骤沿着交付。还量化了导航和可交付MCO计划之间的剂量差异。在导航和可输送条件下选择为可接受的MCO计划与标准优化相比，直肠保留相似（33.7 +/- 1.8戈伊vs 35.5 +/- 4.2戈伊，p = 0.117）。导航和可递送MCO计划之间的剂量差异随着直肠回避的优先级增加而增加。如果选择了最佳可输送MCO，与标准优化相比，观察到直肠剂量显著降低（30.6 +/- 1.4戈伊vs 35.5 +/- 4.2戈伊，p = 0.047）。然而，在某种程度上，改善是以较少的适形剂量分布为代价的，这导致3个耐受水平中的2个的膀胱剂量显著更高。总之，与标准优化相比，使用MCO可以为前列腺癌患者创建类似的IMRT计划。在MCO中存在关于将导航计划转换为可交付孔径的限制，特别是对于强调避开关键结构的计划。最大限度地减少这些差异将为使用MCO计划接受放疗的前列腺癌患者提供更好的治疗质量。(C)2014年美国医学剂量学家协会。
Efficacy of inverse planning is becoming increasingly important for advanced radiotherapy techniques. This study's aims were to validate multicriteria optimization (MCO) in RayStation (v2.4, RaySearch Laboratories, Sweden) against standard intensity-modulated radiation therapy (IMRT) optimization in Oncentra (v4.1, Nucletron BV, the Netherlands) and characterize dose differences due to conversion of navigated MCO plans into deliverable multileaf collimator apertures. Step-and-shoot IMRT plans were created for 10 patients with localized prostate cancer using both standard optimization and MCO. Acceptable standard IMRT plans with minimal average rectal dose were chosen for comparison with deliverable MCO plans. The trade-off was, for the MCO plans, managed through a user interface that permits continuous navigation between fluence-based plans. Navigated MCO plans were made deliverable at incremental steps along a trajectory between maximal target homogeneity and maximal rectal sparing. Dosimetric differences between navigated and deliverable MCO plans were also quantified. MCO plans, chosen as acceptable under navigated and deliverable conditions resulted in similar rectal sparing compared with standard optimization (33.7 +/- 1.8 Gy vs 35.5 +/- 4.2 Gy, p = 0.117). The dose differences between navigated and deliverable MCO plans increased as higher priority was placed on rectal avoidance. If the best possible deliverable MCO was chosen, a significant reduction in rectal dose was observed in comparison with standard optimization (30.6 +/- 1.4 Gy vs 35.5 +/- 4.2 Gy, p = 0.047). Improvements were, however, to some extent, at the expense of less conformal dose distributions, which resulted in significantly higher doses to the bladder for 2 of the 3 tolerance levels. In conclusion, similar IMRT plans can be created for patients with prostate cancer using MCO compared with standard optimization. Limitations exist within MCO regarding conversion of navigated plans to deliverable apertures, particularly for plans that emphasize avoidance of critical structures. Minimizing these differences would result in better quality treatments for patients with prostate cancer who were treated with radiotherapy using MCO plans. (C) 2014 American Association of Medical Dosimetrists.