Peulen Heike, Belderbos José, Rossi Maddalena, Sonke Jan-Jakob
Department of Radiation Oncology, The Netherlands Cancer Institute (NKI), Amsterdam, The Netherlands.
Department of Radiation Oncology, The Netherlands Cancer Institute (NKI), Amsterdam, The Netherlands.
Radiother Oncol. 2014 Mar;110(3):511-6. doi: 10.1016/j.radonc.2014.01.010. Epub 2014 Feb 20.
Large tumor motion leads to large treatment volumes with an Internal Target Volume (ITV) based approach, whereas mid-ventilation (MidV) based Planning Target Volumes (PTV) margins typically lead to smaller treatment volumes. The purpose of this study was to evaluate the MidV approach on clinical outcome data of Stereotactic Body Radiotherapy (SBRT) in NSCLC.
297 patients with 314 peripheral tumors treated from 2006 to 2012 were retrospectively analyzed. In all patients a 4D-CT was acquired and the MidV-CT-scan was selected. Tumor amplitudes were determined in left-right (LR), cranio-caudal (CC) and anterior-posterior (AP) direction, to calculate patient specific PTV margins.
The median LR, CC and AP tumor amplitudes were 2mm (0-16 mm), 4mm (0-39 mm) and 3mm (0-18 mm), respectively, yielding a median CTV-to-PTV margin of 8mm. An ITV+5mm based PTV margin would have been bigger in 47% of the patients. After a median follow up of 22 months, local recurrence occurred in six patients (2%). Two year LC and OS were 98% and 67%, respectively.
Using the MidV approach combined with online image guidance an excellent LC of 98% was established with SBRT. This provides clinical support that incorporating respiratory motion into the PTV margin is a safe approach.
基于内部靶区（ITV）的方法，大肿瘤运动导致大治疗体积，而基于中期呼吸时相（MidV）的计划靶区（PTV）边界通常导致较小的治疗体积。本研究的目的是评估MidV方法对非小细胞肺癌立体定向体部放疗（SBRT）临床结局数据的影响。
回顾性分析2006年至2012年治疗的297例患者的314个周围型肿瘤。所有患者均进行了4D-CT扫描，并选择了MidV-CT扫描。确定肿瘤在左右（LR）、头脚（CC）和前后（AP）方向的振幅，以计算患者特异性PTV边界。
LR、CC和AP方向肿瘤振幅的中位数分别为2mm（0 - 16mm）、4mm（0 - 39mm）和3mm（0 - 18mm），CTV到PTV边界的中位数为8mm。在47%的患者中，基于ITV + 5mm的PTV边界会更大。中位随访22个月后，6例患者（2%）出现局部复发。两年局部控制率（LC）和总生存率（OS）分别为98%和67%。
采用MidV方法结合在线图像引导，SBRT建立了98%的优异局部控制率。这为将呼吸运动纳入PTV边界是一种安全方法提供了临床支持。
