不同分割剂量同步推量调强放疗治疗肺癌脑转移瘤的安全性分析

目的:分析不同分割剂量同步推量调强放疗治疗肺癌脑转移瘤的安全性及生存情况。方法:选取肺癌脑转移瘤患者75例，随机分为3组，均实施同步推量调强放疗，其中A组放疗方案为全脑40 Gy/20f（2.0 Gy/f）+瘤区同步推量46 Gy/20f（2.3 Gy/f），B组方案为全脑40 Gy/20f（2.0 Gy/f）+瘤区同步推量52 Gy/20f（2.6 Gy/f），C组方案为全脑40 Gy/20f（2.0 Gy/f）+瘤区同步推量58 Gy/20f（2.9 Gy/f）。放疗开始后，对3组患者危及器官（眼球、晶体、视神经、脑干）平均剂量及最大剂量和3组患者放疗相关不良反应进行比较。治疗结束后定期复查颅脑MRI评价疗效，观察3组患者1年生存率。结果:A、B、C组危及器官平均剂量及最大剂量差异不显著（P>0.05）；A、B、C组急性放疗不良反应发生率差异不显著（P>0.05），晚期神经系统不良反应发生率亦差异不显著（P>0.05），3级放疗不良反应低于5%，无4级放疗不良反应发生。随访1年，C组生存率高于A、B组（P<0.05）。结论:同步推量调强放疗治疗肺癌脑转移瘤是一种安全有效的方法，随着放疗剂量增加，疗效有增加趋势。

Safety analysis of simultaneous integrated boost intensity-modulated radiotherapy with different fractional doses in lung cancer brain metastases

Abstract: Objective To discuss the safety of simultaneous integrated boost intensity-modulated radiotherapy with different fractional doses for lung cancer brain metastases, and to analyze the survival rate. Methods Seventy-five patients with brain metastases from lung cancer were selected and randomly divided into 3 groups, and all of them underwent simultaneous integrated boost intensity-modulated radiotherapy. The radiotherapy regimen was the whole brain 40 Gy/20f (2.0 Gy/f) + simultaneous integrated boost to tumor 46 Gy/20f (2.3 Gy/f) in group A, the whole brain 40 Gy/20f (2.0 Gy/f) + simultaneous integrated boost to tumor 52 Gy/20f (2.6 Gy/f) in group B, and the whole brain 40 Gy/20f (2.0 Gy/f) + simultaneous integrated boost to tumor 58 Gy/20f (2.9 Gy/f) in group C. The mean dose and maximum dose delivered to organs-at-risk (eyeball, lens, optic nerve, brain stem), and radiotherapy-induced adverse reactions were compared among 3 groups. After the completion of treatment, all patients underwent regular craniocerebral MRI for evaluating curative effect, and 1-year survival rate was also analyzed. Results The comparison among 3 groups showed that no significant difference was found in the mean dose and maximum dose delivered to organs-at-risk (P>0.05) and the incidence of acute radiotherapy-induced adverse reactions (P>0.05). Moreover, there was no significant difference in the incidence of late neurological adverse reactions (P>0.05). The incidence of radiotherapy-induced adverse reaction of grade 3 was less than 5%, and no radiotherapy-induced adverse reaction occurred. After 1 year of follow-up, the survival rate of group C was higher than that of group A and group B (P<0.05). Conclusion Simultaneous integrated boost intensity-modulated radiotherapy is a safe and effective method for treating brain metastases of lung cancer. With the increase of radiation dose, the curative effect is enhancing.