非小细胞肺癌三维适形放疗所致重度放射性肺炎与剂量体积直方图分析

目的 探讨非小细胞肺癌三维适形放疗所致重度(≥3级)放射性肺炎(RP)与剂量体积直方图(DVH)参数之间的关系.方法 94例非小细胞肺癌患者予以三维适形放疗,对临床参数及DVH参数与重度RP发生的关系进行单因素、多因素Logistic分析.结果 年龄、性别、KPS评分、第1秒用力呼气容积、体重减轻、肺基础疾病、外科手术史和化疗史与重度RP的发生差异无统计学意义(P>0.05).单因素Logistic回归分析结果显示,除了总剂量以外,受到20、30或加Gy以上剂量照射的肺体积占全肺总体积的百分数(V20、V30、V40)、平均剂量(MLD)和正常组织并发症概率(NTCP)与重度RP的发生差异均有统计学意义(P<0.01);在多因素Logistic回归分析中,MLD、V30与重度RP的发生差异有统计学意义(P<0.01);当MLD<10 Gy、10～20 Gy、>20 Gy时,重度RP的发生率分别为0、21%(8/39)、35%(7/20),当V30<25%、25%～35%、>35%时,重度RP的发生率分别为0、12%(4/33)、38%(11/29).结论 MLD和V30是重度RP发生的重要预测因素,应该分别被限制到≤20 Gy和≤35%,以减少重度RP的发生.

Analysis of relationship between severe radiation pneumonitis and dose-volume histogram parameters for non-small cell lung cancer treated with three-dimensional conformal radiation therapy

Objective To explore the relationship between severe(≥grade 3 ) radiation pneumonitis (RP) and dose-volume histogram (DVH) parameters for non-small cell lung cancer (NSCLC) treated with three-dimensional conformal radiation therapy (3-DCRT). Methods Ninety-four patients with NSCLC treated with 3-DCRT were retrospectively analyzed. Clinical parameters were analyzed. DVH parameters analyzed were V20, V30, V40,mean lung dose (MLD),normal tissue complication probability(NTCP) ,and total dose. Results Age,sex, Karnofsky scored, performance status, forced expiratory volume in 1 second,presence of weight loss, preexisting lung disease, history of thoracic surgery, and history of chemotherapy were not associated with the risk of severe RP(P>0.05). However,in univariate analyses, V20, V30, V40, MID and NTCP were associated with severe RP(P<0.01). In multivariate analysis, MID and V30 were variable associated with severe RP(P<0.01). The severe RP was 0 when MLD < 10 Gy and 21%(8/39) when MLD between 10 Gy and 20 Gy but 35%(7/20) when MLD > 20 Gy,it was 0 when V30 < 25% and 12%(4/33) when V30 between 25% and 35% but 38%(11/29) when V30 >35%. Conclusion MLD and V30 are significant predictive factors for severe RP and they should be limited to ≤20 Gy and ≤ 35% in order to reduce severe RP.