乳腺癌调强放疗后放射性肺炎的临床和剂量学相关因素分析

Analysis of clinical and dosimetric factors related to radiation pneumonitis after intensity⁃modulated radiotherapy in breast cancer

目的分析乳腺癌术后接受调强放疗患者的临床特征和剂量学参数与放射性肺炎之间的相关性,为术后放疗计划的制定提供参考。方法回顾性分析2020年1月至2021年12月在同济大学附属第十人民医院接受术后放疗的乳腺癌患者的临床资料,收集患者的临床特征、患侧肺体积(ipsilateral lung volume,ILV)、平均肺剂量(mean lung dose,MLD)和体积剂量参数V5~V50,分析其与放射性肺炎的相关性。结果177例乳腺癌患者中75例发生放射性肺炎,其中1级占93.3%,2级占6.7%。单因素分析显示,双靶治疗、内乳区放疗、MLD、V13、V15、V20、V25、V30、V35、V40、V45、V50均与放射性肺炎发生有关(均P<0.05)。多因素分析发现,V35和V50均是放射性肺炎发生的独立危险因素(均P<0.05)。受试者工作特征曲线分析显示,以V35的20.27%作为截断值,其预测放射性肺炎的敏感度和特异度分别为42.7%和77.5%,AUC为0.619;以V50的3.155%作为截断值,其预测放射性肺炎的敏感度和特异度分别为50.7%和75.5%,AUC为0.626。结论V35和V50均是放射性肺炎发生的独立危险因素,降低高剂量区V35和V50对减少放射性肺炎的发生有重要意义。

Objective To analyze the correlation between clinical characteristics and dosimetric factors for the patients receiving intensity‐modulated radiotherapy after breast cancer surgery,and to provide reference for the formulation of postoperative radiotherapy plan.Methods The data of breast cancer patients who received postoperative radiotherapy in Tenth People's Hospital Affiliated to Tongji University from January 2020 to December 2021 were retrospectively analyzed.Clinical characteristics,ipsilateral lung volume(ILV),mean lung dose(MLD)and volumetric dosimetric parameters V5-V50 were collected to analyze the correlation with the radiation pneumonitis.Results 75 cases of 177 breast cancer patients developed radiation pneumonitis;among these cases,93.3%were grade 1 and 6.7%were grade 2.Univariable analysis showed that double target therapy,internal mammary lymph node radiotherapy,MLD,V13,V15,V20,V25,V30,V35,V40,V45,and V50 were all associated with the occurrence of radiation pneumonitis(all P<0.05).Multivariable analysis showed that both V35 and V50 were independent risk factors for the occurrence of radiation pneumonitis(all P<0.05).The receiver operator characteristic curve showed that the sensitivity and specificity of predicting radiation pneumonitis with 20.27%of V35 as the cut‐off value were 42.7%and 77.5%,respectively,with an AUC of 0.619.The sensitivity and specificity of predicting radiation pneumonitis with 3.155%of V50 as the cut‐off value were 50.7%and 75.5%,respectively,with an AUC of 0.626.Conclusions Both V35 and V50 are independent risk factors for the occurrence of radiation pneumonitis,and minimizing the high‐dose region V35 and V50 are of great significance in reducing the incidence of radiation pneumonitis.