射线能量对应用RapidArc进行肝脏多发性肿瘤放疗的剂量学影响  

Dosimetric difference in RapidArc planning for radiotherapy of multiple hepatic malignancy using different photon energy

作　　者：巩贯忠[1] 尹勇[1] 翟德胤[1] 刘同海[1] 宋金龙[2] 卢洁[1] 陈进琥[1] 王若峥[1] 

机构地区：[1]山东省放射肿瘤学重点实验室山东省医学科学院山东省肿瘤医院物理室,济南250117 [2]山东省放射肿瘤学重点实验室山东省医学科学院山东省肿瘤医院介入科,济南250117

出　　处：《国际肿瘤学杂志》2012年第5期391-395,共5页Journal of International Oncology

基　　金：基金项目：山东省自然科学基金资助项目（ZR2010HM071）;山东省科技攻关项目（2011GGX10119）

摘　　要：目的探讨应用6MV和15MVX射线容积调强放疗（RapidArc）进行肝脏多发性恶性肿瘤放射治疗的剂量学差异。方法选取12例多发的肝脏恶性肿瘤（原发5例，继发7例）患者进行自由呼吸下的三维计算机断层成像（3D—CT）模拟定位。针对同一患者分别应用6MV和15MVX射线设计单个和两个358。全弧的RapidArc计划，处方量为2Gy/次×25次。比较不同RapidArc计划间剂量学差异。结果4种RapidArc计划均能满足临床要求。4种RapidArc计划的适形指数（cI）、均匀性指数（HI）、靶区最大剂量和最小剂量间的差异均无统计学意义（P〉0．05），CI均可达0．91，HI均达0．88。双弧RapidArc计划中正常肝脏V5、V10、V15略高于单弧计划，V20、V25、V30、V35、V40低于单弧计划。正常肝脏的V5至V40、胃、十二指肠、脊髓受量在不同RapidArc计划之间的差异均无统计学意义（P〉0．05），6MVX射线RapidArc计划的机器跳数较15MV的平均增加12％。结论应用全弧RapidArc技术进行肝脏多发恶性肿瘤放疗时，6MVX射线可作为首选。Objective To investigate the dosimetric difference in the application of RapidArc using 6 and 15 MV X-rays for radiotherapy of multiple hepatic malignancy. Methods A total of 12 cases with multiple hepatic tumors （ primary 5 cases and secondary 7 cases） were selected. All patients underwent the three dimensional CT simulation in free breathing. For each patient, RapidArc plans with single or two 358° arcs using 6 or 15 MV X-rays were designed respectively, the prescription dose was 2Gy per fraction × 25 fractions. The dosimetric differences were compared among RapidArc plans. Results All of RapidArc plans could meet the clinical requirement. There were no significant differences in the conformity index （CI）, homogeneity index （HI）, the maximum dose and the minimum dose of PTV among RapidArc plans （P 〉 0.05 ）. All the CI could get to 0.91 and HI could get to 0.88. In the RapidArc plans with two 358° arcs, the V5, V10, V15 of normal liver were higher than with single arc, while V20, V25, V30, V35, V40 were lower than with single arc. There were no significant differences in the different radiation dose of normal liver, stomach, duodenum and spinal cord among different plans （P 〉 0.05）. The monitor units of RapidAre plans using 6 MV X-rays increased 12% compared to 15 MV averagely. Conclusion The 6 MV X-ray would be selected chiefly in the radiotherapy of multiple haptic tumor using RapidAre with whole arc （s）.

关 键 词：肝肿瘤 辐射剂量 放射疗法 

分 类 号：R730.55[医药卫生—肿瘤]