Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands.
Radiother Oncol. 2010 Dec;97(3):437-42. doi: 10.1016/j.radonc.2010.09.027. Epub 2010 Nov 11.
Volumetric modulated arc therapy (RapidArc) allows for fast delivery of stereotactic body radiotherapy (SBRT) delivery in stage I lung tumors. We compared dose distributions and delivery times between RapidArc and common delivery techniques in small tumors.
In 18 patients who completed RapidArc SBRT for tumors measuring <70 cm(3), new treatment plans were generated using non-coplanar 3D conformal fields (conf-SBRT) and dynamic conformal arc radiotherapy (DCA). For 9 patients with tumors adjacent to the chest wall, co-planar intensity-modulated radiotherapy (IMRT) plans were also generated. PTV dose coverage, organs at risk (OAR) doses and treatment delivery times were assessed.
RapidArc plans achieved a superior conformity index (CI) and lower V(45 Gy) to chest wall (p<0.05) compared to all other techniques. RapidArc led to a small increase in V(5 Gy) to contralateral lung compared to conf-SBRT (4.4±4% versus 1.2±1.8%, p=0.011). For other OAR, RapidArc and conf-SBRT plans were comparable, and both were superior to DCA plans. Delivery of a 7.5 Gy-fraction required 3.9 min (RapidArc), 11.6 min (conf-SBRT), and 12 min (IMRT).
In stage I lung tumors measuring <70 cm(3), RapidArc plans achieved both the highest dose conformity and shortest delivery times.
容积调强弧形治疗（RapidArc）可实现Ⅰ期肺部肿瘤立体定向体部放疗（SBRT）的快速递送。我们比较了 RapidArc 和常见的小肿瘤递送技术之间的剂量分布和递送时间。
在 18 例肿瘤体积<70cm3 且完成 RapidArc SBRT 的患者中，使用非共面 3D 适形野（conf-SBRT）和动态适形弧形放疗（DCA）生成新的治疗计划。对于 9 例肿瘤毗邻胸壁的患者，还生成了共面调强放疗（IMRT）计划。评估了 PTV 剂量覆盖、危及器官（OAR）剂量和治疗递送时间。
与所有其他技术相比，RapidArc 计划实现了更好的适形指数（CI）和更低的胸壁 V45Gy（p<0.05）。与 conf-SBRT 相比，RapidArc 导致对侧肺 V5Gy 略有增加（4.4±4%对 1.2±1.8%，p=0.011）。对于其他 OAR，RapidArc 和 conf-SBRT 计划相似，且均优于 DCA 计划。7.5Gy 分次的递送需要 3.9 分钟（RapidArc）、11.6 分钟（conf-SBRT）和 12 分钟（IMRT）。
在体积<70cm3 的Ⅰ期肺部肿瘤中，RapidArc 计划实现了最高的剂量适形度和最短的递送时间。
