逆向调强放射治疗肺癌患者发生放射性肺炎相关因素分析

Analysis of factors of radiation pneumonitis in patients with lung cancer treated with intensity-modulated radiation therapy

目的分析逆向调强放射治疗(IMRT)肺癌患者的临床资料和放疗计划的物理参数,评估临床因素、物理参数与放射性肺炎发生的关系。方法回顾性分析63例实施IMRT的肺癌患者资料,比较发生放射性肺炎和未发生放射性肺炎患者治疗计划的剂量体积直方图及临床影响因素。分析病理、肿瘤位置、同步化疗、照射剂量和放疗方式等临床数据,剂量学参数包括肺V5、V10、V15、V20、V25、V30、V35、V40和平均剂量等物理参数。分析上述因素对放射性肺炎发生率的影响。结果发生2级以上放射性肺炎19例。单因素分析显示照射总剂量和病理类型为小细胞肺癌与放射性肺炎相关。多因素分析显示仅V5与放射性肺炎相关。结论实施肺癌IMRT治疗时,需考虑病理类型及严格限制两肺V5,对于敏感的肺组织,低剂量亦可产生损伤。

Objective To evaluate the correlation of clinical factors and radiation therapy factors with incidence of radiation pneumonitis in patients with lung cancer treated with intensity-modulated radiation therapy （ IMRT）. Methods The medical records of 63 patients with lung cancer treated with IMRT were retrospectively analysed. The dose volume histogram of treatment program and clinical influencing factors were compared between patients with radiation pneumonitis and those without radiation pneumonitis. The clinical parameters were observed, which included pathology, tumor location, concurrent chemotherapy, dose and pattern of radiation, and the dosimetric factors included Vs, Vlo, Vt5, V20, V25, V30, V35, V40 and mean lung dose. The effect of above factors on the incidence of radiation pneumonitis was analysed. Results Among the 63 patients, 19 experienced radiation pneumonitis. Univariate analysis revealed that total dose and small cell lung cancer as pathological type were significantly associated with the incidence of radiation pneumonitis. Multivariate analysis indicated that only V5 was the risk factor of radiation pneumonitis. Conclusion Pathological type and V5 value should be considered in the IMRT for lung cancer, and low dose may also cause injury to sensitive lung tissues.