Department of Radiation Oncology, Wake Forest University, Winston-Salem, North Carolina, USA.
Int J Radiat Oncol Biol Phys. 2012 May 1;83(1):e53-9. doi: 10.1016/j.ijrobp.2011.11.059. Epub 2012 Feb 17.
Radiosurgery has been successfully used in selected cases to avoid repeat whole-brain irradiation (WBI) in patients with multiple brain metastases of most solid tumor histological findings. Few data are available for the use of radiosurgery for small-cell lung cancer (SCLC).
Between November 1999 and June 2009, 51 patients with SCLC and previous WBI and new brain metastases were treated with GammaKnife stereotactic radiosurgery (GKSRS). A median dose of 18 Gy (range, 10-24 Gy) was prescribed to the margin of each metastasis. Patients were followed with serial imaging. Patient electronic records were reviewed to determine disease-related factors and clinical outcomes after GKSRS. Local and distant brain failure rates, overall survival, and likelihood of neurologic death were determined based on imaging results. The Kaplan-Meier method was used to determine survival and local and distant brain control. Cox proportional hazard regression was performed to determine strength of association between disease-related factors and survival.
Median survival time for the entire cohort was 5.9 months. Local control rates at 1 and 2 years were 57% and 34%, respectively. Distant brain failure rates at 1 and 2 years were 58% and 75%, respectively. Fifty-three percent of patients ultimately died of neurologic death. On multivariate analysis, patients with stable (hazard ratio [HR] = 2.89) or progressive (HR = 6.98) extracranial disease (ECD) had worse overall survival than patients without evidence of ECD (p = 0.00002). Concurrent chemotherapy improved local control (HR = 89; p = 0.006).
GKSRS represents a feasible salvage option in patients with SCLC and brain metastases for whom previous WBI has failed. The status of patients' ECD is a dominant factor predictive of overall survival. Local control may be inferior to that seen with other cancer histological results, although the use of concurrent chemotherapy may help to improve this.
放射外科已成功用于某些病例，以避免大多数实体瘤组织学发现的多发性脑转移患者再次进行全脑照射（WBI）。对于小细胞肺癌（SCLC），使用放射外科的相关数据较少。
1999 年 11 月至 2009 年 6 月，51 例 SCLC 患者在 WBI 后出现新的脑转移，采用伽玛刀立体定向放射外科（GKSRS）治疗。每个转移灶边缘规定的中位剂量为 18 Gy（范围，10-24 Gy）。对患者进行连续影像学检查。通过患者电子病历确定 GKSRS 后的疾病相关因素和临床结果。根据影像学结果确定局部和远处脑失败率、总生存率和神经死亡的可能性。采用 Kaplan-Meier 法确定生存及局部和远处脑控制情况。采用 Cox 比例风险回归分析确定疾病相关因素与生存之间的关联强度。
整个队列的中位生存时间为 5.9 个月。1 年和 2 年局部控制率分别为 57%和 34%。1 年和 2 年远处脑失败率分别为 58%和 75%。53%的患者最终死于神经死亡。多因素分析显示，有稳定（风险比[HR] = 2.89）或进展性（HR = 6.98）颅外疾病（ECD）的患者总体生存率较无 ECD 证据的患者差（p = 0.00002）。同期化疗可改善局部控制（HR = 89；p = 0.006）。
GKSRS 是 WBI 治疗失败的 SCLC 伴脑转移患者的可行挽救治疗选择。患者 ECD 的状况是预测总体生存率的主要因素。尽管同期化疗可能有助于改善局部控制，但局部控制率可能低于其他癌症的组织学结果。
