局部晚期非小细胞肺癌调强放疗与三维适形放疗的剂量学及临床疗效分析

An Analysis of Dosimetric and Clinical Effect of Intensity Modulated Radiotherapy and Three-dimensional Conformal Radiotherapy for Locally Advanced Non-small Cell Lung Cancer

[目的]分析比较局部晚期非小细胞肺癌（NSCLC）调强放疗（IMRT）与三维适形放疗（3D-CRT）的临床疗效及对靶区和危及器官的剂量学差异。[方法]回顾性分析局部晚期非小细胞肺癌102例,其中52例采用3D-CRT,50例采用IMRT治疗,处方剂量PTV：56~64Gy/28~33次,比较两组的临床疗效和不良反应。选择其中10例患者的CT定位图像,分别设计IMRT和3D-CRT计划,给予DT：64Gy/32f照射,用剂量体积直方图（DVH）评价2种治疗计划的靶区和危及器官的剂量参数。[结果]10例IMRT计划中肺的V20、V30及肺平均剂量低于3D-CRT,而V5高于3D-CRT计划（P〈0.05）,V10无差异（P〉0.05）。IMRT的靶区适形指数（CI）和靶区均匀指数（HI）均优于3D-CRT（P〈0.05）,IMRT计划中脊髓的最大剂量（Dmax）较3D-CRT低（P〈0.05）。IMRT组与3DCRT组的1、2、3年生存率分别为82.0%、46.0%、28.0%和76.9%、36.5%、19.2%,中位生存期分别为22个月和18个月（P〉0.05）,1、2、3年无进展生存率分别为70.0%、34.0%、16.0%和63.5%、25.0%、9.6%,中位PFS分别为18个月和16个月（P〉0.05）。同步放化疗患者1、2、3年总生存率、无进展生存率分别为90.5%、71.4%、47.6%和85.7%、52.3%、33.3%,与序贯化放疗相比有显著性差异（P〈0.05）。IMRT组与3D-CRT组的近期疗效分别为76.0%、55.8%（P〈0.05）,急性放疗反应发生率两组无显著性差异。[结论]调强放射治疗可提高非小细胞肺癌近期疗效,调强放射治疗的计划可以提高靶区的适形度和均匀性,同时降低危及器官的剂量。

[Purpose] To investigate the clinical efficacy of intensity modulated radiotherapy（IMRT）and three-dimensional conformal radiotherapy（3D-CRT） for locally advanced non-small cell lung cancer（NSCLC）,and to compare the dosimetric difference in planning target volume（PTV） and organ at risk（OAR） between IMRT and 3D-CRT.[Methods] Patients with locally advanced NSCLC（n=102）were retrospectively analyzed. Among the patients,52 cases were treated by 3D-CRT and 50 cases were treated by IMRT.The plans were designed to deliver 56~64 Gy in 28~33 fractions.The therapeutic efficacy and adverse events were compared between the two groups. Ten of the patients were enrolled for the further analysis：IMRT and 3D-CRT plans were designed for each patient.The total radiation dose was 64Gy/32 f.The dose distributions of PTV and OAR were analyzed by the dose volume histogram（DVH）.[Results] IMRT plans of 10 patients decrease the lungs V20,V30,the mean dose and increase the lungs V5（P〈0.05）.The lungs V10 under both modes have no statistical significance（P〉0.05）.The conformal indices（CI） and homogeneity indices（HI） of PTV in IMRT were better than those in 3D-CRT（P〈0.05）.The cord max dose in IMRT was low in 3D-CRT（P〈0.05）.The 1-,2-,3-year survival（OS） of the IMRT group and 3D-CRT group were 82.0%,46.0%,28.0% and 76.9%,36.5%,19.2%,respectively. The median survival periods of two groups were 22 and 18 months（P〉0.05）.The 1-,2-,3-year progression-free survival（PFS） of two groups were 70.0%,34.0%,16.0% and63.5%,25.0%,9.6% respectively. The median PFS periods of two groups were 18 and 16 months（P〉0.05）. The 1-,2-,3-year OS and PFS of subgroup arms with concurrent chemoradiotherapy were90.5%,71.4%,47.6% and 85.7%,52.3%,33.3% respectively. There were significant difference in concurrent chemoradiotherapy group and sequential chemoradiotherapy group（P〈0.05）. The short term response of two groups were 76.0% and 55.8% respectively（P〈0.05）. There was no significant difference in acute radiotoxicity reaction between the two groups. [Conclusions] IMRT for patients with NSCLC can improve the shot-term response. And it could improve CI and HI of PTV,with decreased dose of OAR.