Clinical outcomes for a novel 6 degrees of freedom image guided localization method for frameless radiosurgery for intracranial brain metastases
Clinical outcomes for a novel 6 degrees of freedom image guided localization method for frameless radiosurgery for intracranial brain metastases
复制标题
一种新型 6 自由度图像引导定位方法用于颅内脑转移瘤无框架放射外科手术的临床结果
作者：
R. Prabhu;A. Dhabaan;W. Hall;T. Ogunleye;I. Crocker;W. Curran;H. Shu
立体定向放射外科(SRS)是一种公认的治疗颅内脑转移瘤的方法，精确度为亚毫米。无框架放射外科(FRS)由于其侵入性较小的要求，正在成为有框架SRS的替代方案。本研究的目的是描述一种新的6自由度CT引导的脑转移瘤FRS定位方法的临床结果和局部失败模式。从2009年1月至2011年7月，42例患者接受了基于直线加速器的FRS，共94例颅内转移瘤。78%的治疗部位为完整转移瘤，22%的治疗部位为切除空洞。55%的患者曾接受过脑放射治疗(45%的SRS，26%的全脑放射治疗)。1年精算局部复发率为18%，中位影像随访期为13.2个月。单分数等效剂量是预测局部复发的最重要因素。1年远脑复发率为58%，总复发率为69%。粗放型放射坏死率为3%。在10个局部复发事件中，8个(80%)仅在现场发生，1个(10%)仅在边缘发生，1个(10%)同时发生。使用这种新的FRS定位方法，仅在场内失败的模式的优势表明，地理缺失不是局部复发的主要原因。1年的局部控制率可与其他类似的已发表的有框架和无框架的放射外科系列相媲美。
Stereotactic radiosurgery (SRS) is an accepted method of treatment for intracranial brain metastases with sub-millimeter accuracy. Frameless radiosurgery (FRS) is becoming an alternative to framed SRS due to its less invasive requirements. The purpose of this study is to describe the clinical outcomes and local patterns of failure for a novel 6 degrees of freedom CT guided method of localization for FRS of intracranial brain metastases. 42 patients underwent linear accelerator-based FRS to 94 intracranial brain metastases between 01/2009 and 07/2011. 78 and 22 % of treated sites were intact metastases and resection cavities, respectively. 55 % of patients had undergone prior brain radiotherapy (45 % SRS, 26 % whole brain radiation therapy). The 1 year actuarial local recurrence rate was 18 %, with a median imaging follow-up period of 13.2 months. Single fraction equivalent dose was the most important predictor of local recurrence. The 1 year actuarial first distant brain recurrence and total intracranial recurrence rate was 58 and 69 %, respectively. The crude radiographic radiation necrosis rate was 3 %. Of the 10 local recurrence events, 8 (80 %) were in-field only, 1 (10 %) was marginal only, and 1 (10 %) was both. The preponderance of in-field only patterns of failure suggests that geographic miss is not a major contributor to local recurrence using this novel localization method for FRS. The 1 year local control rate is comparable to other similar published series of framed and frameless radiosurgery.