摘要
目的探讨胸中段食管癌在三维适形放疗(3DCRT)中靶区移位的变化及放疗过程中复位对靶区剂量学、正常组织剂量学的影响,讨论3DCRT中复位的必要性及可行性。方法选择15例胸中段食管癌患者接受40Gy治疗后进行复位,利用图像融合观察肿瘤靶区移动范围。制定定位和复位两套放疗计划,对比复位后对靶区D100、D95及肺平均、心脏平均、脊髓最大剂量的影响。结果胸中段食管癌患者在放疗40Gy后,肿瘤计划靶体积(PTV)边缘头脚方向平均移位0.5cm(0.41～0.45),前后方向平均移位0.2cm(-0.3～0.6cm),左右方向平均移位0.2cm(-0.7～0.5cm),差异均无统计学意义(P<0.05),头脚方向回缩最明显。肿瘤靶区D100及D95两个指标比较具有统计学意义。肺平均、心脏平均、脊髓最大剂量指标变化无统计学意义,但其数值上比较,复位计划(plan 2)中正常组织受照剂量均比定位计划(plan 1)小。结论胸中段食管癌患者在三维适形放疗中进行复位可减少靶区移位影响,同时更改放疗计划可减少正常组织的受照剂量,有必要进行复位。
Objective To observe the target shift changes and the impact on the target dosimetry and normal tissue dosimetry after carrying out the second simulation,in the three-dimensional conformal radiotherapy（3DCRT）of the middle thoracic esophageal cancer,and to explore the necessity and feasibility of the second simulation for the middle thoracic esophageal cancer in the three-dimensional conformal radiotherapy（3DCRT）.Methods 15 patients with middle thoracic esophageal cancer patients to accept 40Gy before the second simulation.The use of image fusion observed tumor target range of movement.Make another radiation treatment planning after second simulation,to compare the D100,D95 and pulmonary average,the heart of the average,spinal cord maximum dose changes with the first planning.Results The PTV edge change after radiotherapy 40Gy for the patients with middle thoracic esophageal tumor,with average shift 0.5cm（0.41~0.45）in the head and foot direction,with average shift 0.2cm（-0.3~0.6cm）in the front and back direction,with average shift 0.2cm（-0.7~0.5cm）in the left and right direction,respectively,but no statistically significant difference for all of them,and retraction most obvious in the head and foot direction.The D100 and D95 for tumor target are statistically significant.There is no statisticale significance for the lung average,heart average,spinal cord maximum dose,but their value,the second planning（plan2）is smaller than first planning（plan1）for the normal tissue dose.Conclusions Second simulation for the middle thoracic esophageal cancer patients in the three-dimensional conformal radiotherapy can reduce the target shift influence,and change the radiation treatment planning can reduce normal tissue exposure doses.It is necessary to make a second simulation in the process of 3DCRT for the middle thoracic esophageal cancer patients.
出处
《中国肿瘤临床与康复》
2013年第1期9-13,共5页
Chinese Journal of Clinical Oncology and Rehabilitation
基金
山东省自然基金项目(ZR2009CM131)
