容积旋转调强放射治疗肺癌患者放射性肺炎发生的相关因素分析

Analysis of factors predicting radiation pneumonitis in volumetric modulated arc therapy of lung cancer

目的:分析肺癌患者行容积旋转调强放射治疗(VMAT)的临床因素和物理因素,探讨临床因素和物理因素与放射性肺炎(RP)发生的关系。方法:回顾性分析2014年7月1日~2016年10月1日在秦皇岛市第一医院住院初次接受VMAT治疗的肺癌患者,共计40例。比较发生RP和未发生RP患者的临床资料和放疗物理参数,随访时间大于10个月,根据影像学检查及RTOG标准明确RP,探讨上述因素与大于或等于2级RP的关系。结果:发生2级及以上RP患者10例。单因素分析显示,性别、年龄、病理类型、临床分期、是否有糖尿病、是否手术、肿瘤位置、是否吸烟、是否化疗及放疗前有无阻塞性肺炎症等临床因素与RP的发生均无显著相关性(P>0.05);V_5、V_10、V_13、V_15、V_20、V_25、V_30、V_35、V_40、平均剂量(D_(mean))、处方剂量(D_p)和PTV体积大小等物理因素中,V_5、V_10、V_13、V_15与RP发生的相关性具有统计学意义(P=0.018,0.023,0.012,0.004),其余物理因素与RP发生的相关性均无统计学意义(P>0.05)。多因素分析显示,临床因素和物理因素中只有V_5与RP发生的相关性具有统计学意义(P=0.003,OR=29.571)。结论:肺癌患者进行VMAT放射治疗时,V_5与RP的发生显著相关。肺癌患者放射治疗选择ARC治疗方式时,应严格限制低剂量受照体积V_5、V_10、V_13、V_15,尤其是V_5,使RP发生的概率降到最低。

Objective To analyze the clinical factors and physical factors of patients receiving volumetric modulated arc therapy（VMAT） for lung cancer, and evaluate the correlation of clinical factors and physical factors with the incidence of radiation pneumonitis（RP）. Methods The information of 40 patients receiving the first VMAT for lung cancer in the First Hospital of Qinhuangdao between July 2014 and October 2016 were retrospectively analyzed. The clinical data and physical factors were compared between patients developing RP and those without developing RP. The RP was defined by the imaging examination and RTOG standard after over 10-month follow-up studies. The correlations of clinical factors and physical factors with the incidence of RP of grade 2 or above were analyzed. Results Ten patients developed RP of grade 2 or above. The results of univariate analysis revealed that the clinical factors, including gender, age, pathological type, clinical stage, diabetes mellitus,surgery, tumor location, smoking, chemotherapy and obstructive pneumonia before radiotherapy, didn＇t have any significant correlations with the incidence of RP（P0.05）. Among the physical factors of V5, V10, V13, V15, V20, V25, V30, V35, V40, Dmean,Dpand planning target volume, only V5, V10, V13, V15 had statistical correlations with the incidence of RP（P=0.018, 0.023, 0.012, 0.004）and no statistical correlations were found between the other factors and the incidence of RP（P〉0.05）. The results of multivariate analysis indicated that of all clinical and physical factors, only V5 was the risk factor of RP（P=0.003, OR=29.571）. Conclusion The incidence of RP is significantly correlated with V5 in lung cancer patients treated with VMAT. When patients with lung cancer treated with ARC, the volume of low-dose irradiation（V5, V10, V13 and V15） should be strictly restricted, especially V5, in order to minimize the incidence of RP.