中晚期非小细胞肺癌放射治疗剂量学研究

Comparison of dosiology in conventional radiotherapy,three-dimensional conformal radiation therapy and intensity-modulated radiation therapy in the treatment of non-small cell lung cancer

目的探讨应用常规放疗、三维适形放疗(3DCRT)和调强适形放疗(IMRT)治疗中晚期非小细胞肺癌(NSCLC),靶区适形度和危及器官的受量情况。方法对经病理证实的10例中晚期NSCLC(Ⅲ～Ⅳ期)患者行回顾性研究,计划靶区处方剂量66Gy,利用TPS对每个患者分别设计常规、3DCRT、IMRT三种放疗计划,通过剂量体积直方图,比较三种计划对肿瘤靶区和正常组织器官的剂量分布。结果IMRT与3DCRT、常规放疗比较:肿瘤靶区有更好的剂量分布;明显减少了肺V30、V40值;心脏V35及食管V45亦减少;肺V5值提高;脊髓受量较3DCRT有所加大。结论IM-RT在靶区剂量分布上明显优于常规放疗和3DCRT,同时能更好的保护正常组织。

Objective To evaluate systematically conventional radiotherapy（RT） , three-dimensional conformal radiation therapy（3DCRT） and intensity-modulated radiation therapy（IMRT） used to treat non-small-cell lung cancer, investigate the conformity and the dose to organs at risk. Methods A retrospective treatment planning study was performed for 10 pathologically proven patients with Stage m to IV NSCLC, one target volume was predefined：PTV which was given 66 Gy. Three plans were designed for each patient ：RT,3DCRT and IMRT plans. Dose volume histogram were used to compared doses distributions for tumor and normal tissue in three plans. Results Target volume dosimetric distribution of IMRT was better than RT and 3DCRT ;the volume of lung V20 ,lung V30 ,esophageal V45 and heart V35 of IMRT were lower than RT and 3DCRT ;the volume of lung V5 of IMRT was higher than RT and 3DCRT ;the dose at the spinal cord of IMRT was higer than 3DCRT. Conclusion Target volume dosimetric distribution of IMRT is more precise as compared with RT and 3DCRT, and the IMRT planning decrease the surrounding normal tissues and organs radiation injury.