晚期肺癌非共面和共面IMRT剂量学比较研究

Comparative study of coplanar and non-coplanar intensity-modulated radiotherapy in advanced lung cancer

目的 比较研究晚期肺癌非共面IMRT计划剂量学分布特点,并观察计划执行安全性.方法 对14例晚期肺癌患者优化设计共面和非共面5、7个野IMRT计划,对比共面、非共面各组内及组间计划优化结果.观察4例患者非共面7个野计划的执行过程.结果 随射野数目增加共面及非共面靶区CI均改善（P值均为0.000）,非共面野靶区Dmean、Dmax、V95％、HI亦有改善（P=0.001、0.001、0.009、0.000）;共面野全肺、患、健肺V5增加（P =0.000、0.002、0.000）及全肺Dmean增加（P=0.000）,相反非共面野全肺、健肺V5降低（P =0.001、0.005）.组间非共面7个野较共面5个野计划靶区各指标均改善（P值均为0.000）;各肺V20均降低（P值均为0.000）且全肺Dmean、V30及健肺V5降低（P=0.000、0.001、0.000）,脊髓Dmax亦有减少（P=0.033）;但患肺V5及心脏Dmean增加（P =0.000、0.003）.较共面7个野计划患肺V5及心脏Dmean亦增加（P =0.000、0.048）,但全肺及健肺V5均降低（所有P =0.000）.4例患者均顺利完成非共面IMRT,全程未发生碰撞风险.结论 非共面7个野IMRT计划改善了靶区剂量分布,降低肺V20、Dmean也控制了低剂量肺体积增加趋势且临床实施安全有效,值得推荐.

Objective To study the dosimetry and safety of the non-coplanar IMRT plan for advanced lung cancer.Methods The two groups IMRT plans were designed with coplanar （5,7F） and non-coplanar field （5,7F-n） for patients.To compare the dosimetry of two groups and perform 4 patients F7-n IMRT plan.Results With the increase of the fields in each group PTV＇s CI were improved （all P =0.000）,especially the 7F-n plan PTV＇s Dmean,Dmax,V95％ and HI also were improved （P=0.001,0.001,0.009,0.000） ; in the coplanar group each lung＇ s V5 increased （P =0.000,0.002,0.000） and whole lung＇s Dmean increased （P =0.000）,but non-coplanar group whole lung＇s and contralateral lung＇s V5 reduce （P =0.001,0.005）.Between the groups,7F-n plan PTV＇s indicators were all improved to compared with 5F plan （all P =0.000）,and each lung＇s V20 reduced （all P =0.000）,and whole lung＇s Dmean,V30,contralateral lung＇ s V5 reduced （P =0.000,0.001,0.000）,and spinal cord＇ s Dmax also reduced （P =0.033）,but ipsilateral lung＇s V5 and heart＇s Dmean increased （P =0.000,0.003）;with compared to 7F plan,the 7F-n＇s ipsilateral lung＇s V5 and heart＇s Dmean also increased （P =0.000,0.048）,but whole lung＇ s and contralateral lung＇s V5 decreased （all P =0.000）.Four patients were performed successfully non-coplanar IMRT treatment,no collision occurred.Conclusions 7 fields non-coplanar IMRT plan not only improve the dose distribution of PTV,but also effectively control the volume of low dose lung increase,lung V20 and Dmean reduce too.Thus recommended to use this design in patients with advanced lung cancer for radiotherapy