Department of Neurosurgery, Stanford University Medical Center, Stanford, California 94305-5847, USA.
Int J Radiat Oncol Biol Phys. 2012 Oct 1;84(2):336-42. doi: 10.1016/j.ijrobp.2011.12.009. Epub 2012 May 30.
Given the neurocognitive toxicity associated with whole-brain irradiation (WBRT), approaches to defer or avoid WBRT after surgical resection of brain metastases are desirable. Our initial experience with stereotactic radiosurgery (SRS) targeting the resection cavity showed promising results. We examined the outcomes of postoperative resection cavity SRS to determine the effect of adding a 2-mm margin around the resection cavity on local failure (LF) and toxicity.
We retrospectively evaluated 120 cavities in 112 patients treated from 1998-2009. Factors associated with LF and distant brain failure (DF) were analyzed using competing risks analysis, with death as a competing risk. The overall survival (OS) rate was calculated by the Kaplan-Meier product-limit method; variables associated with OS were evaluated using the Cox proportional hazards and log rank tests.
The 12-month cumulative incidence rates of LF and DF, with death as a competing risk, were 9.5% and 54%, respectively. On univariate analysis, expansion of the cavity with a 2-mm margin was associated with decreased LF; the 12-month cumulative incidence rates of LF with and without margin were 3% and 16%, respectively (P=.042). The 12-month toxicity rates with and without margin were 3% and 8%, respectively (P=.27). On multivariate analysis, melanoma histology (P=.038) and number of brain metastases (P=.0097) were associated with higher DF. The median OS time was 17 months (range, 2-114 months), with a 12-month OS rate of 62%. Overall, WBRT was avoided in 72% of the patients.
Adjuvant SRS targeting the resection cavity of brain metastases results in excellent local control and allows WBRT to be avoided in a majority of patients. A 2-mm margin around the resection cavity improved local control without increasing toxicity compared with our prior technique with no margin.
鉴于全脑放疗（WBRT）引起的神经认知毒性，对于手术后脑转移瘤切除后延迟或避免 WBRT 的方法是可取的。我们最初使用立体定向放射外科（SRS）靶向切除腔的经验显示出有希望的结果。我们检查了术后切除腔 SRS 的结果，以确定在切除腔周围增加 2 毫米边缘对局部失败（LF）和毒性的影响。
我们回顾性评估了 1998 年至 2009 年间治疗的 112 名患者的 120 个腔。使用竞争风险分析分析与 LF 和远处脑失败（DF）相关的因素，以死亡为竞争风险。通过 Kaplan-Meier 乘积限法计算总生存率（OS）率；使用 Cox 比例风险和对数秩检验评估与 OS 相关的变量。
以死亡为竞争风险，12 个月时 LF 和 DF 的累积发生率分别为 9.5%和 54%。单因素分析显示，扩大 2 毫米边缘的腔与 LF 降低相关；有和没有边缘的 12 个月 LF 累积发生率分别为 3%和 16%（P=.042）。有和没有边缘的 12 个月毒性发生率分别为 3%和 8%（P=.27）。多因素分析显示，黑色素瘤组织学（P=.038）和脑转移瘤数量（P=.0097）与更高的 DF 相关。中位 OS 时间为 17 个月（范围 2-114 个月），12 个月 OS 率为 62%。总体而言，72%的患者避免了 WBRT。
脑转移瘤切除术后辅助 SRS 靶向切除腔可获得良好的局部控制，并使大多数患者避免 WBRT。与我们之前无边缘的技术相比，切除腔周围增加 2 毫米边缘可改善局部控制而不增加毒性。
