射线能量选择对逆向调强放疗计划影响的研究  

The effect of energy selection to the dose distribution of inverse planning intensity-modulated radiation therapy

作　　者：冯丽娜[1] 白彦灵[1] 陈林[1] 云惟康[1] 谷安鑫[1] 刘莉莉[1] 

机构地区：[1]哈尔滨医科大学附属第三医院(黑龙江省肿瘤医院)放射物理科,150081

出　　处：《中华放射肿瘤学杂志》2011年第5期428-431,共4页Chinese Journal of Radiation Oncology

摘　　要：目的研究X线能量对逆向调强放疗计划的影响，为临床实施常规调强放疗和容积调强弧形治疗（VMAT）提供能量选择参考。方法选取8个不同病种病例，每个病例采用单弧（1Arc=360°）VMAT、等角度9个野、等角度5个野调强方式进行逆向治疗计划设计，在每种计划方式中又分别选用4、6、8、15MVX线能量。靶区选取适形指数、均匀指数、靶外体积指数，串型危及器官选取平均剂量Dmean、2％体积对应的最大剂量D2，并型危及器官选取平均剂量Dmean、某一剂量水平的体积Vx，评估治疗计划结果，分析能量对逆向计划的影响。结果统计分析显示：在3种计划方式下，靶K适形指数的F=0．07、0．08、0．06，P=0．976、0．971、0．981，均匀指数的F=0．13、0．51、0．09，P=0．939、0．679、0．965，靶外体积指数的F=0．15、0．31、0．15，P=0．930、0．818、0．931；每一病例在3种计划方式下危及器官的F〈0．20，P〉0．05。结论用逆向治疗计划系统进行调强放疗、VMAT计划设计时中低能量x线（6、8MV）完全满足需要，而高能x线（15MV）并不具有明显的剂量分布优势。Objective To study the dose distribution of the intensity modulated radiation therapy （IMRT） and volumetric modulated arc therapy （VMAT） inverse plans with different energy X-ray, to provide a reference of energy options for radiation therapy. Methods Eight cases with different disease were chosen, the plan for each case were finished with 1Arc （360°） VMAT, 9 fields IMRT and 5 fields IMRT. For each plan project, the energy selections were 4 MV, 6 MV, 8 MV and 15 MV. In the evaluation, homogeneity index （ HI ） , conformity index （ CI ） and external volume index （ EVI ） of target, the average dose （D ） and 2% volume in dose volume histogram （D2 ） of serial organs at risk （OARs） , the average dose （ D ） and a dose level volume （ Vx ） of parallel OARs were chosen and compared . Results Statistical analysis showed that： For the target, the result of HI were F = 0. 13,0. 51,0. 09, P = 0. 939, 0. 679,0. 965 ,CI were F = 0. 13,0. 51,0. 09,P = 0. 939,0. 679,0. 965, EVI were F = 0. 15,0. 31,0. 15, P =0. 930,0. 818,0. 931, respectively; For the OARs of each patient, F 〈 0. 20, P 〉 0. 05. All results indicated there was little difference in option of energy for the same field pSroject. Conclusions The resuhs indicate that the middle and low energy X-ray （6 MV or 8 MV） can satisfy the needs of IMRT and VMAT radiotherapy. Compared with middle and low energy, the high energy X-ray （15 MV ） showed little advantage in dose distribution.

关 键 词：逆向治疗计划 X线能量 调强放疗 容积调强弧形治疗 

分 类 号：R730.55[医药卫生—肿瘤]