Volumetric Modulated Arc Therapy and Conventional Intensity-modulated Radiotherapy for Simultaneous Maximal Intraprostatic Boost: a Planning Comparison Study
Volumetric Modulated Arc Therapy and Conventional Intensity-modulated Radiotherapy for Simultaneous Maximal Intraprostatic Boost: a Planning Comparison Study
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DOI：
10.1016/j.clon.2009.01.014
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发表时间：
2009-06-01
影响因子：
3.4
通讯作者：
Otto, K.
中科院分区：
文献类型：
--
作者：
Shaffer, R.;Morris, W. J.;Otto, K.
目的：体积调制弧线治疗（VMAT）是调强放疗（IMRT）的一种新扩展，其中优化的三维剂量分布可以在单个龙门旋转中传递。这种优化算法是瓦里安的RapidArc的前身。本研究的目的是比较传统的静态九场IMRT （cIMRT）和VMAT在不超过器官危险（OAR）剂量-体积限制的情况下尽可能多地将临床靶体积（CTV）提高到88.8 Gy的能力。材料与方法：针对10例局限性前列腺癌患者，采用共同的计划目标制定最佳的cIMRT和VMAT放疗方案：(1)治疗>=计划靶体积（PTV）的98%至>=处方剂量的95% （74 Gy， 37份）；(2)将桨剂量控制在预定范围内；(3)尽可能多地治疗前列腺CTV（不包括尿道），达到处方剂量的120% (= 88.8 Gy)；（四）在目标体积内外保持最大剂量限制；(5)适形指数（95%等剂量体积/ PTV体积）=处方剂量的120% （P = 0.002）。所有剂量限制都保持在预定的限度内。VMAT和cIMRT平均需要949和1819个监测单位，分别需要3.7和9.6分钟来提供单个辐射分数。结论：VMAT比cIMRT能够在不违反OAR剂量限制的情况下将CTV提高到>= 120%，并且使用的监护单元减少48%。治疗时间比cIMRT减少61%。R.谢弗等。(2009)。临床肿瘤学21,401-407 (C) 2009皇家放射学院。Elsevier Ltd.出版。版权所有。
Aims: Volumetric modulated arc therapy (VMAT) is a novel extension of intensity-modulated radiotherapy (IMRT) where an optimised three-dimensional dose distribution may be delivered in a single gantry rotation. This optimisation algorithm is the predecessor to Varian's RapidArc. The aim of this study was to compare the ability of conventional static nine-field IMRT (cIMRT) and VMAT to boost as much of the clinical target volume (CTV) as possible to 88.8 Gy without exceeding organ at risk (OAR) dose-volume constraints.Materials and methods: Optimal cIMRT and VMAT radiotherapy plans were produced for 10 patients with localised prostate cancer using common planning objectives: (1) Treat >= 98% of the planning target volume (PTV) to >= 95% of the prescription dose (74 Gy in 37 fractions); (2) keep OAR doses within predefined limits; (3) treat as much of prostate CTV (minus urethra) as possible to >= 120% of prescription dose (= 88.8 Gy); (4) keep within maximum dose limits in and out of target volumes; (5) conformality index (volume of 95% isodose/volume of PTV) = 120% of the prescription dose (P = 0.002). All dose constraints were kept within predefined limits. VMAT and cIMRT required an average of 949 and 1819 monitor units and 3.7 and 9.6 min, respectively, to deliver a single radiation fraction.Conclusions: VMAT is able to boost more of the CTV to >= 120% than cIMRT without contravening OAR dose constraints, and uses 48% fewer monitor units. Treatment times were 61% less than with cIMRT. Shaffer, R. et at. (2009). Clinical Oncology 21, 401-407 (C) 2009 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.