肺癌不同放射治疗技术剂量学比较研究  

Comparison of three radiotherapy technics in three-dimensional dosimetric planning for non-small cell lung cancer

作　　者：吴开良[1] 蒋国梁[1] 廖源[1] 周莉均[1] 

机构地区：[1]复旦大学附属肿瘤医院放射治疗科,上海200032

出　　处：《中华放射肿瘤学杂志》2002年第4期231-234,共4页Chinese Journal of Radiation Oncology

摘　　要：目的　应用三维治疗计划系统评价肺癌不同的照射方法 ,以明确肺癌三维适形放射治疗的优势。方法　选用 1 3例ⅢA、ⅢB期非小细胞肺癌病例 ,采用Cadplan 6 .0 .8三维治疗计划系统设计放射治疗计划 ,每例均做 3个计划 ,分别为常规、常规加适形和适形放射治疗计划 ,计划的总剂量均为 66Gy。用剂量体积直方图 (DVH)比较靶区剂量和正常组织的受照射剂量的差异。结果　 3种治疗计划均能满足靶区剂量要求 ,剂量变化差异无显著性意义。常规、常规加适形和适形放射治疗计划的照射适形指数分别为 0 .1 3、0 .2 4和 0 .35 ;全肺接受≥ 2 0Gy照射的体积百分比的均数分别为 32 %、2 6 %和 2 5 % ;脊髓的最大剂量分别为 42、49和 33Gy ;食管照射≥ 50Gy的体积百分比的均数分别为32 %、34 %和 2 2 % ;心脏平均剂量的均数分别为 1 8、1 5和 1 2Gy。结论　肺癌常规放射治疗设野方法基本能满足靶区的剂量学要求 ,然而正常组织的受照剂量明显高于其他 2种治疗计划。三维适形放射治疗的主要优势在于减少正常组织的受照剂量。Objective To assess and delineate the dosimetric shortcomings of conventional radiotherapy planning,as compared with the three dimensional treatment planning system, and to obtain a better technique in the treatment of lung cancers.Methods Thirteen patients with stage ⅢA ⅢB non small cell lung cancer were chosen in the present study. Using the Cadplan 6.0.8 treatment planning system , three different methods of radiotherapy planning: conventional planning, conventional and conformal planning, and conformal planning were designed for each patient. The total radiation dose was 66 ?Gy and DVHs were used to assess the dosimetric distribution in the gross tumor volume and the surrounding organs at risk. Results No significant dosimetric disparity in the target volume was found among the three designs, according to anticipated therapeatic requirements. The conformity indices were 0.13,0.24 and 0.35 for these three radiotherapy designs. The mean lung volumes which received radiation dose of≥20?Gy were 32%,26% and 25%.The mean maximum dose at the spinal cord were 42?Gy,49?Gy and 33?Gy.The mean esophageal volume which received radiation of ≥50?Gy were 32%,34% and 22%, and the mean radiation dose to the heart were 18?Gy,15?Gy and 12?Gy,respectively. Conclusions Conventional radiotherapy planning is able to meet the demands of dosimetric requirements for radiation treatment of lung cancers. The three dimensional conformal radiation therapy planning system is able to provide superior delivery of high dose to the target volume without inflicting too high a risk to the surrounding normal tissues and organs.

关 键 词：肺癌 剂量学 比较研究 放射疗法 三维治疗计划系统 剂量体积直方图 

分 类 号：R734.2[医药卫生—肿瘤] R730.[医药卫生—临床医学]