Volumetric modulated arc therapy with robust optimization for larynx cancer
Volumetric modulated arc therapy with robust optimization for larynx cancer
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DOI：
10.1016/j.ejmp.2019.01.012
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发表时间：
2019-02-01
影响因子：
3.4
通讯作者：
Nagata, Yasushi
中科院分区：
文献类型：
--
作者：
Miura, Hideharu;Doi, Yoshiko;Nagata, Yasushi
目的：本研究的目的是进行鲁棒优化和规划目标体积（PTV）为基础的优化计划使用体积调制弧治疗（VMAT）之间的比较，通过评估扰动剂量引起的设置不确定性在喉癌放疗的定位偏移方法：10例早期（T1- 2N 0）声门癌。临床靶体积（CTV），颈动脉和脊髓轮廓由放射肿瘤学家。基于PTV的优化计划和稳健的优化计划分别在D-50%到PTV和D-98%到CTV处进行归一化。通过指定用户定义的等中心点偏移值，使用扰动剂量评价两种优化计划。CTV剂量（D-98%、D-50%和D-2%）、均匀性指数（HI）和一致性指数在基于PTV的优化计划和稳健的优化计划之间比较了CI 95%、CI 80%和CI 50%以及对颈动脉和脊髓的剂量。与基于PTV的优化计划相比，稳健的优化计划表现出上级CTV覆盖率和颈动脉剂量降低（p < 0.05）。基于PTV的优化计划和稳健优化计划之间的HI、CI 95%和脊髓剂量没有显著差异（p > 0.05）。与基于PTV的优化计划相比，稳健优化计划显示出更好的CI 80%和CI 50%（p < 0.05）。计划扰动评估表明，稳健优化计划有小的变化，CTV，颈动脉，脊髓相比，PTV为基础的优化plannes.Conclusions的剂量稳健优化计划可能是一个合适的治疗方法，在喉癌患者的放疗。
Purpose: The aim of this study was to perform a comparison between robust optimization and planning target volume (PTV)-based optimization plans using volumetric modulated arc-therapy (VMAT) by evaluating perturbed doses induced by localization offsets for setup uncertainties in larynx cancer radiation therapy.Methods: Ten patients with early-stage (T1-2N0) glottis carcinoma were selected. The clinical target volume (CTV), carotid arteries, and spinal cord were contoured by a radiation oncologist. PTV-based and robust optimization plans were normalized at D-50% to the PTV and D-98% to the CTV, respectively. Both optimization plans were evaluated using perturbed doses by specifying user defined shifted values from the isocenter. CTV dose (D-98%, D-50%, and D-2%), homogeneity index (HI) and conformity index (CI95%, CI80%, and CI50%), as well as doses to the carotid arteries and spinal cord were compared between PTV-based and robust optimization plans.Results: The robust optimization plans exhibited superior CTV coverage and a reduced dose to the carotid arteries compared to the PTV-based optimization plans (p < 0.05). HI, CI95% and the dose to the spinal cord did not significantly differ between the PTV-based and robust optimization plans (p > 0.05). The robust optimization plans showed better CI80% and CI50% compared to the PTV-based optimization plans (p < 0.05). Plan perturbed evaluations showed that the robust optimization plan has small variations in the doses to the CTV, carotid arteries, and spinal cord compared to the PTV-based optimization plan.Conclusions: The robust optimization plan may be a suitable treatment method in radiotherapy for larynx cancer patient.