食管癌不同部位病灶的3D-CRT及IMRT治疗计划比较

目的比较调强放疗(IMRT)与三维适形放疗(3D-CRT)在食管癌放疗剂量学的差异。方法应用IMRT治疗计划系统治疗食管颈段与胸上、胸中段及胸下段癌患者各10例,分别采用3D-CRT及IMRT,比较2种计划PTV靶区各项参数及各项正常组织受照射体积、剂量、平均肺受量(MLD)及正常组织并发症概率(NTCP)。结果颈段及胸上段组,靶区适形度指数(CI)及靶区计划体积(PTV)剂量学比较,差异有统计学意义。胸中段组,IMRT较3D-CRT在CI、靶区剂量不均匀指数(HI)、肺组织保护方面的优势明显,差异有统计学意义。胸下段组,靶区CI、PTV剂量学及HI的比较,差异有统计学意义。结论 3种不同部位的食管癌中,IMRT的靶区CI明显优于3D-CRT;胸中、下段癌的HI,IMRT明显优于3D-CRT;食管颈段及胸上段癌、胸下段癌在肺及脊髓保护方面,IMRT未见明显优于3D-CRT;食管胸中段癌,IMRT的肺组织保护明显优于3D-CRT,但在脊髓及心脏保护方面无明显优势。

Comparison of 3D-CRT and IMRT on different locations of esophageal carcinoma

Objective To compare the differences between IMRT and 3D-CRT on radiation dosimetry of esophageal carcinoma.Methods Patients with cervical oesophagus,upper,middle and lower thoracic portion(10 cases each) received 3D-CRT and IMRT.The various parameters of PTV target area,normal tissue irradiated volume,dose,MLD and NTCP of the two methods were compared.Results There was statistical significance of target area CI and PTV dose in cervical oesophagus group.There was statistical significance of CI,PTV dose,HI and lung tissue protection in middle thoracic group.There was statistical significance of CI,PTV dose,HI in lower thoracic group.Conclusion In the different locations of esophageal carcinoma,the target area CI of IMRT is obviously superior to that of 3D-CRT.The HI of IMRT in middle-lower thoracic carcinoma is obviously superior to that of 3D-CRT.There is no obvious advantage in lung and spinal cord protection of cervical,upper and lower thoracic with IMRT than that with 3D-CRT.In middle thoracic esophageal carcinoma,the lung tissue protection with IMRT is superior to that with 3D-CRT,but there is no obvious advantage in spinal cord and heart protection.