三维适形在中段食管癌放疗中的应用

目的:通过两种三维适形方案与常规方案的对比,明确三维适形技术在中段食管癌放疗中对脊髓及肺保护的优势。方法:对40例中段食管癌患者进行三种放疗方案的比较,A:常规方案(一前野两后斜野),B:在A方案的基础上加三维适形C:在B方案的基础上调整机架角度,实施一后斜野两前斜野。经CT模拟定位后每个病例均用三种方案在3D-TPS计划系统上模拟计算,以60Gy为处方剂量,100%剂量线包绕食管肿瘤,剂量分布评价指标为:18cm长度脊髓平均剂量,左肺平均剂量,左肺V20。结果:一后斜两前斜野的三维适形方案具有明显的优势,脊髓平均受量为11.89Gy,远低于常规方案的22.01Gy(P<0.01);左肺平均受量为16.09Gy,亦低于常规方案的18.01Gy,左肺V20平均值为28.67%,低于常规方案的33.87%。结论:中段食管癌的三维适形方案优于传统的常规方案。

Three dimension conformal radiation therapy for mid -thoracic esophagus

Objective:To evaluate the advantage in the treatment of mid-thoracic esophagus with three dimension conformal radiation therapy.Methods: To compare the difference of 40 patients with three treating plans.A: conventional plan(A-P,PL-AR,PR-AL), B:3D-CRT plan(A-P,PL-AR,PR-AL),C:3D-CRT plan(AL-PR,AR-PL,PL-AR),after CT simulation,all patients were caculated in 3D-TPS with three plans,prescribe dose was 60Gy,100%IDL involved the tumor,the evaluating parameters were average dose of 18cm cord,average dose of left lung and V20 of the left lung.Results: The plan with 3D-CRT(AL-PR,AR-PL,PL-AR)was better than others,average dose of cord was 11.89Gy,far lower than 22.01Gy of the conventional plan(P<0.01),average dose of left lung was 16.09Gy,lower than 18.01Gy of conventional plan,V20 of left lung was 28.67%,lower than 33.87% of the conventional plan.Conclusion: Three dimension conformal radiation therapy of mid-thoracec esophagus is better than the conventional therapy.