广泛期小细胞肺癌胸部IMRT后发生放射性肺炎的危险因素分析

目的 评价广泛期小细胞肺癌(SCLC)化疗后接受胸部IMRT, 发生放射性肺炎(RP)的临床和剂量-体积因素。 方法 回顾性分析2007年至2012年接受化疗和IMRT的130例初治广泛期SCLC患者, 化疗方案以顺铂、依托泊甙方案为主, 放疗平均剂量为55.3 Gy(32~67 Gy)。RP采用常见不良反应事件评价标准(4.0版)进行评价, 分析放疗结束后2级及以上RP发生的危险因素。通过单因素和多因素统计学方法分析预测因子。 结果 全组中位随访时间37个月(4~66个月)。37例(28.5%)患者出现了≥2级的RP。单因素分析显示, 年龄和剂量学参数(双肺V5、V10、V20、V30、平均肺剂量、双肺体积)与RP显著性相关; 多因素分析显示, 只有双肺V5是≥2级RP的独立危险因素。 结论 多个临床和剂量学参数与RP的发生存在风险相关性, 尤其是双肺V5。对化疗有效的广泛期SCLC患者行胸部放疗时, 应综合考虑这些因素, 适当降低V5的体积。

Risk factor analysis for predicting radiation pneumonitis in extensive stage small cell lung cancer patients receiving IMRT thoracic radiotherapy

Objective To evaluate the clinical factors and dose-volume histogram-based factors as predictors of radiation pneumonitis (RP)in extensive-stage small cell lung cancer (ES-SCLC) patients treated with thoracic IMRT after chemotherapy.Methods Medical records of 130 ES-SCLC patients irradiated in our institution between 2007 and 2012 were retrospectively reviewed.Most patients received an initial chemotherapy regimen of combined carboplatin and etoposide or with cisplatin combined with etoposide.The median thoracic radiation dose was 55.3 Gy (32-67 Gy) with 1.8-2.3 Gy per fraction.RP was graded according to Common Terminology Criteria for Adverse Events version 4.0,and RP at a grade of ≥ Ⅱ is considered as a complication.Univariate and multivariate analyses were conducted to identify the predictive factors.Results Median follow-up period was 37 months (range:4-66 months).A total of 37 patients (28.5％) showed an RP grade of ≥ Ⅱ.The univariate analysis revealed that in the entire population,age and many dosimetric parameters (VS,V10,V20,V30,mean lung dose,and total lung volume)were significantly associated with RP.By contrast,multivariate analysis showed that only V5 was significantly associated with RP.Conclusions In this study,a number of clinical and dosimetric factors are associated with a high risk of RP.However,V5 was the only significant factor associated with this condition.Multiple clinical and dosimetric factors should be considered in IMRT planning for ES-SCLC patients receiving thoracic radiotherapy after chemotherapy.It is proposed that V5 should be kept low to reduce the development of RP in ES-SCLC patients after chemotherapy.