Chen Joseph C T, Bugoci Darlene M, Girvigian Michael R, Miller Michael J, Arellano Alonso, Rahimian Javad
Department of Neurological Surgery, Southern California Permanente Medical Group, Los Angeles, California, USA.
Neurosurg Focus. 2009 Dec;27(6):E6. doi: 10.3171/2009.8.FOCUS09131.
Radiosurgery is an important and well-accepted method in the management of brain metastases. Using conventional frame-based techniques, high lesional control rates are expected. The introduction of image-guided techniques allows for improved patient comfort and workflow. Some controversy exists as to the accuracy of imageguided techniques and consequently the impact they might have on control of brain metastases (as opposed to the level of control achieved with frame-based methods). The authors describe their initial 15-month experience with image-guided radiosurgery (IGRS) using Novalis with ExacTrac for management of brain metastases.
The authors reviewed the cases of brain metastasis treated by means of IGRS in their tertiary regional radiation oncology service over a 15-month period. During the study period 54 patients (median age 57.9 years) harboring 108 metastases were treated with IGRS. The median time from cancer diagnosis to development of brain metastasis was 12 months (range 0-144 months). The median tumor volume was 0.98 cm(3) (range 0.03-19.07 cm(3)). The median prescribed dose was 18 Gy to the 80% isodose line (range 14-20 Gy). Lesions were followed with postradiosurgery MR imaging every 2-3 months following treatment.
The median follow-up period was 9 months (range 0-20 months). Median actuarial survival was 8.6 months following IGRS. Eight patients with 18 lesions died within the first 2 months after the procedure, before scheduled follow-up imaging. Thus 90 lesions (in 46 patients) were followed up with imaging studies. Lesions that were unchanged or reduced in size were considered to be under control. The 6-month actuarial lesion control rate was 88%. Smaller lesions (< 1 cm(3)) had a statistically improved likelihood of complete imaging response (loss of all contrast-enhancement p = 0.01).
Image-guided radiosurgical treatment of brain metastases resulted in high rates of tumor control comparable to control rates reported for frame-based methods. High control rates were seen for small lesions in which spatial precision in dose delivery is critical. These data suggests that in regard to lesion control, IGRS using Novalis with ExacTrac is equivalent to frame-based radiosurgery methods.
放射外科是治疗脑转移瘤的一种重要且被广泛接受的方法。使用传统的基于框架的技术，预期能获得较高的病灶控制率。图像引导技术的引入提高了患者的舒适度并优化了工作流程。关于图像引导技术的准确性以及其对脑转移瘤控制的影响（与基于框架的方法所达到的控制水平相比）存在一些争议。作者描述了他们使用带有ExacTrac的Novalis系统进行图像引导放射外科（IGRS）治疗脑转移瘤的最初15个月的经验。
作者回顾了他们在三级区域放射肿瘤学服务中心15个月期间通过IGRS治疗脑转移瘤的病例。在研究期间，54例患者（中位年龄57.9岁）共108个转移灶接受了IGRS治疗。从癌症诊断到发生脑转移的中位时间为12个月（范围0 - 144个月）。中位肿瘤体积为0.98 cm³（范围0.03 - 19.07 cm³）。给予80%等剂量线的中位处方剂量为18 Gy（范围14 - 20 Gy）。治疗后每2 - 3个月通过放射外科术后磁共振成像对病灶进行随访。
中位随访期为9个月（范围0 - 20个月）。IGRS治疗后中位精算生存率为8.6个月。8例患者的18个病灶在术后前2个月内死亡，未进行预定的随访成像。因此，对46例患者的90个病灶进行了成像研究随访。大小未改变或缩小的病灶被认为处于控制之下。6个月的精算病灶控制率为88%。较小的病灶（<1 cm³）在完全影像学反应（所有对比增强消失）方面有统计学上更高的可能性（p = 0.01）。
图像引导放射外科治疗脑转移瘤产生了与基于框架的方法所报告的控制率相当的高肿瘤控制率。对于小病灶，在剂量传递的空间精度至关重要的情况下，观察到了高控制率。这些数据表明，就病灶控制而言，使用带有ExacTrac的Novalis系统的IGRS等同于基于框架的放射外科方法。
