晚期肺癌常规放射治疗的剂量评估  

Conventional and Two-dimensional Conformal Radiotherapy for Advanced Lung Cancer

作　　者：李智华[1] 王伟[1] 王军[1] 孙健[1] 

机构地区：[1]天津市肿瘤防治重点实验室天津医科大学附属肿瘤医院放疗科,天津市300060

出　　处：《中国肿瘤临床》2007年第23期1347-1350,共4页Chinese Journal of Clinical Oncology

摘　　要：目的:对于晚期中心型非小细胞肺癌的放射治疗,常规放射治疗通常采用前后两野对穿照射,肿瘤量达到4000cGy后,改为斜野或侧野水平照射,使肿瘤剂量达到6000cGy。本文通过比较常规放疗和两维适形放疗对肺部肿瘤患者的剂量分布的不同,定性和定量地对常规放射治疗进行评估。方法:选择经病理学或细胞学确诊的肺部恶性肿瘤,肿瘤局部晚期,位置居中无法手术的患者。为每位患者设计两种治疗计划,常规治疗计划和两维适形治疗计划。结果:通过近20例患者的比较,以其中1例患者为例进行量化分析。常规放射照射的照射野均比两维适形放射治疗的照射野大,但是常规放射治疗的前野和后野并没有将整个肿瘤靶区包括。约有2cm×3cm的肿瘤在照射野以外。对于同一位患者,对于两维适形放射治疗中,100%的等剂量线包绕了PTV的98.8%;68%的等剂量线则完全地包绕了PTV。而常规野治疗计划,100%的等剂量线包绕了PTV的98.5%,42%的等剂量线才能100%地将PTV包绕。两维适形放射治疗使脊髓接受4000cGy剂量的体积由80%下降到6.8%;两肺接受2000cGy剂量的体积均下降5%左右。结论:对于晚期中心型非小细胞肺癌的放射治疗,与常规放射治疗相比,适形放射治疗可以大幅度地降低周围危及器官所接受的剂量,但危及器官的受照射体积和剂量仍然较高。要避免放射性肺炎的发生可以通过缩野加量或逆向调强照射技术来达到。Object： To compare conventional radiation treatment with two-dimensional conformal radiation treatment （2DCRT） for advanced lung cancer. Methods： Twenty patients with advanced lung cancer in the middle part of the lung were included in this study. Both of the two treatment methods were prescribed. The total dose of conventional radiotherapy was 6000 cGy. In 2DCRT, the gross tumor volume （GTV） and the planning target volume （PFV） were outlined based on CT images of the patient. Precise Plan 2.03 from the Elekta Company was employed to compute isodoses and DVH. Results： The radiation field of conventional radiotherapy was larger than that of 2DCRT. The PTV was 98.5% and 98.8% in conventional radiotherapy and 2DCRT, respectively. The spinal cord V20 was 6.8% in convenlional radiotherapy and 80.0% in 2DCRT. Conclusion： 2DCRT has advantages over conventional radiotherapy, but it fails to make the lung V20 less than 30%.

关 键 词：晚期肺癌 常规放射治疗 剂量评估 

分 类 号：R734.2[医药卫生—肿瘤]