A COMPARISON OF VOLUMETRIC MODULATED ARC THERAPY AND CONVENTIONAL INTENSITY-MODULATED RADIOTHERAPY FOR FRONTAL AND TEMPORAL HIGH-GRADE GLIOMAS
A COMPARISON OF VOLUMETRIC MODULATED ARC THERAPY AND CONVENTIONAL INTENSITY-MODULATED RADIOTHERAPY FOR FRONTAL AND TEMPORAL HIGH-GRADE GLIOMAS
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DOI：
10.1016/j.ijrobp.2009.03.013
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发表时间：
2010-03-15
影响因子：
7
通讯作者：
Otto, Karl
中科院分区：
文献类型：
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作者：
Shaffer, Richard;Nichol, Alan M.;Otto, Karl
目的：容积调制式弧形治疗（VMAT）是瓦里安RapidArc的前身，是调强放射治疗（IMRT）的一种新型扩展，其中在多叶准直器叶片运动时，在单次机架旋转中输送剂量。叶位置和权重的字段样本沿沿着弧直接优化，并使用可变剂量率。本计划研究比较了七场共面调强放射治疗（cIMRT）与VMAT的高级别胶质瘤，计划靶体积（PTVs）重叠器官的风险（OARs）。方法和材料：10个以前治疗的患者重新计划60戈伊，在30个分数与cIMRT和VMAT使用以下规划目标：98%的PTV覆盖95%的等剂量，而不违反OAR和热点剂量的限制。平均OAR剂量最大限度地减少，而不减少PTV覆盖或违反热点限制。我们比较了剂量体积直方图数据，监测单位，和治疗times.Results：有相当的PTV覆盖范围，均匀性和一致性。与调强放疗相比，VMAT显著降低了最大和平均视网膜、透镜和对侧视神经剂量（p < 0.05）。脑干、视交叉和同侧视神经的剂量相似。对于2-戈伊剂量，平均监测单位如下：cIMRT = 789 +/- 112和VMAT = 363 45（相对减少54%，p = 0.002），平均治疗时间（min）如下：cIMRT = 5.1 +/- 0.4和VMAT = 1.8 +/- 0.1结论：与cIMRT相比，VMAT实现了相等或更好的PTV覆盖和OAR保留，同时使用更少的监视器单元和更短的时间来治疗高级别胶质瘤。(C)2010年爱思唯尔公司
Purpose: Volumetric modulated arc therapy (VMAT), the predecessor to Varian's RapidArc, is a novel extension of intensity-modulated radiotherapy (IMRT) wherein the dose is delivered in a single gantry rotation while the multi-leaf collimator leaves are in motion. Leaf positions and the weights of field samples along the arc are directly optimized, and a variable dose rate is used. This planning study compared seven-field coplanar IMRT (cIMRT) with VMAT for high-grade gliomas that had planning target volumes (PTVs) overlapping organs at risk (OARs).Methods and Materials: 10 previously treated patients were replanned to 60 Gy in 30 fractions with cIMRT and VMAT using the following planning objectives: 98% of PTV covered by 95% isodose without violating OAR and hotspot dose constraints. Mean OAR doses were maximally decreased without reducing PTV coverage or violating hotspot constraints. We compared dose volume histogram data, monitor units, and treatment times.Results: There was equivalent PTV coverage, homogeneity, and conformality. VMAT significantly reduced maximum and mean retinal, lens, and contralateral optic nerve doses compared with IMRT (p < 0.05). Brainstem, chiasm, and ipsilateral optic nerve doses were similar. For 2-Gy fractions, mean monitor units were as follows: cIMRT = 789 +/- 112 and VMAT = 363 45 (relative reduction 54%, p = 0.002), and mean treatment times (min) were as follows: cIMRT = 5.1 +/- 0.4 and VMAT = 1.8 +/- 0.1 (relative reduction 65%, p = 0.002).Conclusions: Compared with cIMRT, VMAT achieved equal or better PTV coverage and OAR sparing while using fewer monitor units and less time to treat high-grade gliomas. (C) 2010 Elsevier Inc.