Quantitative comparison of volumetric modulated arc therapy and intensity modulated radiotherapy plan quality in sino-nasal cancer.
Quantitative comparison of volumetric modulated arc therapy and intensity modulated radiotherapy plan quality in sino-nasal cancer.
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DOI：
10.4103/0971-6203.92715
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发表时间：
2012-01
影响因子：
0.9
通讯作者：
Rizwanullah M
中科院分区：
文献类型：
--
作者：
Sankaralingam M;Glegg M;Smith S;James A;Rizwanullah M
本研究的目的是比较各种剂量学参数的动态MLC调强放射治疗（IMRT）计划与容积调弧治疗（VMAT）计划的鼻窦癌，这是罕见的和复杂的肿瘤治疗与放射治疗。IMRT使用五个字段，共面的矢状面和VMAT采用两个共面弧计划创建了五名患者。通过比较计划靶体积（PTV）中的符合性指数和Sigma指数（剂量均匀性）以及通过比较以下风险器官（OAR）的剂量-体积特征来评估计划：脊髓、脑干、眼睛、同侧和对侧视神经以及接受10%处方剂量（V10%）的脑体积。还比较了交付计划所需的监测器总数。符合性指数被认为是上级在VMAT计划的三名患者和IMRT计划的两名患者。对于所有5例病例，VMAT计划的PTV内剂量均匀性更好。Sigma指数的平均差异为0.68%。在这些患者中评估的任何OAR的IMRT和VMAT计划之间的剂量没有显著差异。与IMRT计划相比，VMAT计划中5名患者中有4名患者的监视器单位显著减少，平均减少66%。本研究发现，对于鼻窦癌的治疗，与IMRT相比，VMAT在PTV内的剂量均匀性方面产生了最小且统计学上不显著的改善。VMAT计划使用的显示器单元数量明显减少。我们在这项研究中得出的结论是，VMAT并没有提供显着改善治疗鼻窦癌比现有的调强放射治疗技术，但结果可能会改变更大的样本患者在这种罕见的条件。
The aim of this study was to compare various dosimetric parameters of dynamic mlc intensity modulated radiotherapy (IMRT) plans with volumetric modulated arc therapy (VMAT) plans for sino-nasal cancers, which are rare and complex tumors to treat with radiotherapy. IMRT using five fields, coplanar in the sagittal plane and VMAT employing two coplanar arc plans were created for five patients. The plans were assessed by comparing Conformity Index and Sigma Index (dose homogeneity) in the Planning Target Volume (PTV) and through comparison of dose-volume characteristics to the following organs at risk (OARs): Spinal cord, brainstem, eye, ipsilateral and contralateral optic nerve and the volume of brain receiving 10% of the prescribed dose (V10%). The total monitor units required to deliver the plan were also compared. Conformity Index was found to be superior in VMAT plans for three patients and in IMRT plans for two patients. Dose homogeneity within the PTV was better with VMAT plans for all five cases. The mean difference in Sigma Index was 0.68%. There was no significant difference in dose between IMRT and VMAT plans for any of the OARs assessed in these patients. The monitor units were significantly reduced in the VMAT plan in comparison to the IMRT plan for four out of five patients, with mean reduction of 66%. It was found in this study that for the treatment of sino-nasal cancer, VMAT produced minimal, and statistically insignificant improvement in dose homogeneity within the PTV when compared with IMRT. VMAT plans were delivered using significantly fewer monitor units. We conclude in this study that VMAT does not offer significant improvement of treatment for sino-nasal cancer over the existing IMRT techniques, but the findings may change with a larger sample of patients in this rare condition.