中晚期食管癌三维适形放疗剂量学及五年生存率影响因素分析

摘要

Objective To explore the optimal dosage for patients with application of three dimensional conformal radiation,and to study the influential factors for 5 year survival rate in patients with middle and terminal esophageal cancer. Methods A total of 70 patients with middle and terminal esophageal cancer were allocated in this study and four kinds of light planes including two fields plus two oblique field(SD1)and one field plus two former oblique fields(SD2)and Maeno plus two posterior oblique fields(SD3)and two fields plus two posterior oblique fields were formulated. The optimal dosage for patients applied with three dimensional conformal planes and the best way of radiation had been studied. Then patients were followed up for five years and influencing factors for five year survival rate in patients were analyzed. Results ①SD3 way in spinal cord by volume was significantly lower than other three kinds of splitting planes in four kinds of splitting planes( P 0. 05).②SD3 was recommended for meeting the maximum tolerated dosage in spinal cord,at the same time it satis-fied V20 = 25%,whole lung Dmean = 13 Gy and spinal cord Dmean = 45 Gy,and the excessive dosage was significantly higher than that of other three kinds of cutting planes( P 0. 05).③The maximum diameter of esophagus and application of SD3 rec- n ommended for cutting flat irradiation were independent factors affecting five-year survival rate of patients. Conclusion Maeno plus two posterior oblique planes were the optimal ways for irradiation and maximum dosage could attain the radical cure. The maximum diameter of esophagus and whether or not applicating SD3 is recommended for cutting flat exposure affects the treatment effect of patients,thus it can be used as an important index for clinically individualized treatment.%目的：探讨中晚期食管癌患者应用三维适形放疗最佳剂量及照射方式，分析中晚期食管癌患者五年生存率的影响因素。方法选取中晚期食管癌患者70例，制定前后两野+两前斜野（ SD1）、两前斜野+一后野（ SD2）、一前野+两后斜野（ SD3）、前后两野+两后斜野（ SD4）四种照射平面，探讨最优照射平面及最佳照射剂量；对患者进行五年随访，分析影响患者五年生存率的因素。结果①四种分割平面中，SD3方式中脊髓受量明显低于其它三种分割平面（ P 0.05）；②四种切割平面中，SD3在脊髓满足最大耐受剂量以及同时满足V20=25％、全肺Dmean=13Gy、脊髓Dmean=45Gy时，最大处方剂量明显高于其它三种切割平面（ P 0.05）；③食管癌最大径及是否应用SD3切割平面照射是影响患者五年生存率的独立因素。结论一前野+两后斜野是最优的照射方式，并且最大照射剂量已经达到根治剂量；食管癌最大径及是否应用SD3切割平面照射影响患者治疗效果，可以作为临床上个体化治疗的重要指标。