Exploratory Study of 4D versus 3D Robust Optimization in Intensity Modulated Proton Therapy for Lung Cancer.
Exploratory Study of 4D versus 3D Robust Optimization in Intensity Modulated Proton Therapy for Lung Cancer.
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肺癌调强质子治疗中 4D 与 3D 稳健优化的探索性研究。
DOI：
10.1016/j.ijrobp.2015.11.002
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发表时间：
2016-05-01
期刊：
影响因子：
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通讯作者：
Bues M
中科院分区：
文献类型：
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作者：
Liu W;Schild SE;Chang JY;Liao Z;Chang YH;Wen Z;Shen J;Stoker JB;Ding X;Hu Y;Sahoo N;Herman MG;Vargas C;Keole S;Wong W;Bues M
在一项探索性方法研究中，比较不确定性和相互作用对肺癌 3D 和 4D 稳健优化调强质子治疗 (IMPT) 计划的影响。为 11 个非随机选择的非小细胞肺癌 (NSCLC) 病例创建了 IMPT 计划：在平均 CT 上的 3D 稳健优化计划，覆盖内部总肿瘤体积密度以照射内部目标体积，以及在 4D CT 上的 4D 稳健优化计划以照射临床目标体积 (CTV)。考虑了常规分割（66 Gy[RBE]，33 次分割）。在4D优化中，各个阶段的CTV接受不均匀的剂量以实现均匀的累积剂量。均方根剂量体积直方图 (RVH) 测量剂量对不确定性的敏感性，RVH 曲线下面积 (AUC) 用于评估计划的稳健性。剂量评估软件对时间依赖性点传递进行建模，将相互作用效应与每个部分的每个区域的随机起始阶段相结合。使用 Wilcoxon 符号秩检验评估比较 CTV 覆盖范围、均匀性和正常组织保留的剂量体积直方图指数。 4D 稳健优化计划导致 CTV 的 AUC 更小（14.26 vs. 18.61 (p=0.001)）、更好的 CTV 覆盖范围 (Gy[RBE]) [D95% CTV: 60.6 vs 55.2 (p=0.001)] 以及更好的 CTV 均匀性 [D5%–D95% CTV: 10.3 vs 17.7 (p=0.002)] 考虑到相互作用效应，4D 稳健优化产生的计划具有更好的目标覆盖率 [D95% CTV：64.5 vs 63.8 (p=0.0068)]、相当的目标同质性和相当的正常组织保护。我们的探索性方法研究表明，与 3D 稳健优化相比，4D 稳健优化的益处最为明显。 4D 稳健优化为正常组织具有可比剂量分布的目标产生了明显更稳健和抗相互作用效应的计划，有必要对更大、更现实的患者群体进行进一步的研究来概括结论。
To compare the impact of uncertainties and interplay effect on 3D and 4D robustly optimized intensity-modulated proton therapy (IMPT) plans for lung cancer in an exploratory methodology study. IMPT plans were created for 11 non-randomly selected non-small-cell lung cancer (NSCLC) cases: 3D robustly optimized plans on average CTs with internal gross tumor volume density overridden to irradiate internal target volume, and 4D robustly optimized plans on 4D CTs to irradiate clinical target volume (CTV). Regular fractionation (66 Gy[RBE] in 33 fractions) were considered. In 4D optimization, the CTV of individual phases received non-uniform doses to achieve a uniform cumulative dose. The root-mean-square-dose volume histograms (RVH) measured the sensitivity of the dose to uncertainties, and the areas under the RVH curve (AUCs) were used to evaluate plan robustness. Dose evaluation software modeled time-dependent spot delivery to incorporate interplay effect with randomized starting phases of each field per fraction. Dose-volume histogram indices comparing CTV coverage, homogeneity, and normal tissue sparing were evaluated using Wilcoxon signed-rank test. 4D robust optimization plans led to smaller AUC for CTV (14.26 vs. 18.61 (p=0.001), better CTV coverage (Gy[RBE]) [D95% CTV: 60.6 vs 55.2 (p=0.001)], and better CTV homogeneity [D5%–D95% CTV: 10.3 vs 17.7 (p=0.002)] in the face of uncertainties. With interplay effect considered, 4D robust optimization produced plans with better target coverage [D95% CTV: 64.5 vs 63.8 (p=0.0068)], comparable target homogeneity, and comparable normal tissue protection. The benefits from 4D robust optimization were most obvious for the 2 typical stage III lung cancer patients. Our exploratory methodology study showed that, compared to 3D robust optimization, 4D robust optimization produced significantly more robust and interplay-effect-resistant plans for targets with comparable dose distributions for normal tissues. A further study with a larger and more realistic patient population is warranted to generalize the conclusions.