预防性放疗：减少扩散型小细胞肺癌的头颅转移

Prophylactic Cranial Irradiation in Extensive Small-Cell Lung Cancer

Background We conducted a randomized trial of prophylactic cranial irradiation in patients with extensive small-cell lung cancer who had had a response to chemotherapy.

Methods Patients between the ages of 18 and 75 years with extensive small-cell lung cancer were randomly assigned to undergo prophylactic cranial irradiation (irradiation group) or receive no further therapy (control group). The primary end point was the time to symptomatic brain metastases. Computed tomography or magnetic resonance imaging of the brain was performed when any predefined key symptom suggestive of brain metastases was present.

Results The two groups (each with 143 patients) were well balanced regarding baseline characteristics. Patients in the irradiation group had a lower risk of symptomatic brain metastases (hazard ratio, 0.27; 95% confidence interval [CI], 0.16 to 0.44; P<0.001). The cumulative risk of brain metastases within 1 year was 14.6% in the irradiation group (95% CI, 8.3 to 20.9) and 40.4% in the control group (95% CI, 32.1 to 48.6). Irradiation was associated with an increase in median disease-free survival from 12.0 weeks to 14.7 weeks and in median overall survival from 5.4 months to 6.7 months after randomization. The 1-year survival rate was 27.1% (95% CI, 19.4 to 35.5) in the irradiation group and 13.3% (95% CI, 8.1 to 19.9) in the control group. Irradiation had side effects but did not have a clinically significant effect on global health status.

Conclusions Prophylactic cranial irradiation reduces the incidence of symptomatic brain metastases and prolongs disease-free and overall survival.

头颅预防性照射减少扩散型小细胞肺癌的转移

背景：
我们进行了一项针对扩散型小细胞肺癌患者的头颅预防性照射，这些患者均对化疗敏感。
方法：
年龄在18～75岁之间的扩散型小细胞肺癌患者被随机分配至放疗组进行预防性头颅照射或是分配至对照组不进行任何进一步的治疗。主要终点是发展至症状性的头颅转移。在出现任何提示转移的关键症状时，就进行头颅的CT或MRI检查。
结果：
两个小组在基线特征方面均是匹配的。放疗组发生症状性头颅转移的分风险较小(hazard ratio, 0.27; 95% confidence interval [CI], 0.16 to 0.44; P<0.001)。一年内头颅转移的累积风险分别是14.6% （放疗组）和40.4%（对照组）， (95% CI, 32.1 to 48.6)。放疗使无病生存时间中位数从12.0周延长至14.7周，使全部的死亡率中位数从5.4个月延长至6.7个月。一年生存率在放疗组是27.1%(95% CI, 19.4 to 35.5) ，在对照组是13.3% (95% CI, 8.1 to 19.9) 。放疗是存在一些副作用，但是临床上没有对患者的整体健康出现显著的影响。
结论：
预防性头颅照射能减少小细胞肺癌的头颅转移，并能延长无病生存时间和整体生存率。