乳腺癌保乳术后容积旋转调强和切线野调强放疗的剂量学比较  

Dosimetric analysis of volumetric modulated arc therapy and intensity modulated radiotherapy for patients undergone breast-conserving operation

作　　者：孙海涛[1] 杨瑞杰[1] 江萍[1] 姜伟娟[1] 李金娜[1] 孟娜[1] 王俊杰[1] SUN Hai-tao;YANG Rui-jieA;JIANG Ping;JIANG Wei-juan;LI Jin-na;MENG Na;WANG Jun-jie(Department of Cancer Radiation, Peking University Third Hospital, Beijing 100191 , China)

机构地区：[1]北京大学第三医院肿瘤放疗科,北京100191

出　　处：《北京大学学报（医学版）》2018年第1期188-192,共5页Journal of Peking University:Health Sciences

基　　金：国家自然科学基金(81071237)资助~~

摘　　要：目的:比较左侧乳腺癌保乳术后容积旋转调强和切线野调强的剂量学差异。方法:选择接受放射治疗的左侧乳腺癌保乳术后患者10例,采用Eclipse计划系统分别设计容积旋转调强(2F-Rapid Arc)与切线野调强(2FIMRT)计划,2F-Rapid Arc采用机架角287°~293°至152°~162°的两个部分弧,中间0°~90°避免照射,2F-IMRT采用机架角301°~311°和125°~135°的切线野照射,处方剂量均为46 Gy/23次,所有计划要求95%靶区体积达到处方剂量。比较2种计划靶区、危及器官剂量分布、机器跳数(MU)和治疗时间。结果:2F-Rapid Arc和2F-IMRT计划均匀性指数分别是1.12±0.02和1.11±0.03(P=0.282),适形度指数分别是0.80±0.03和0.65±0.04(P<0.001),计划靶区(PTV)V110分别是20.98%±14.47%和10.43%±10.49%(P=0.030)。与2F-IMRT计划相比,2F-Rapid Arc计划增加了左侧肺的V5(48.06%±17.32%vs.24.23%±6.56%,P=0.001)、V10(28.89%±9.28%vs.17.07%±4.78%,P=0.004)、D_(mean)[(9.70±2.14)Gy vs.(6.86±1.77)Gy,P=0.002],增加了双肺的V5(22.85%±7.55%vs.11.01%±2.95%,P=0.001]、V10(13.16%±4.33%vs.7.76%±2.16%,P=0.006)、D_(mean)[(4.66±0.95)Gy vs.(3.17±0.82)Gy,P=0.001),但降低了左侧肺的V40(3.58%±1.46%vs.6.19%±3.04%,P=0.006),同时降低了双肺的V40(1.61%±0.64%vs.2.81%±1.39%,P=0.005)。增加了心脏的V5(39.3%±17.19%vs.8.79%±4.24%,P<0.001)、V10(21.31%±13.8%vs.5.73%±3.42%,P=0.002)、V20(7.80%±6.08%vs.4.05%±2.85%,P=0.018)、D_(mean)[(0.64±0.25)Gy vs.(0.29±1.39)Gy,P<0.001],降低了心脏的V40(0.50%±0.40%vs.1.86%±1.94%,P=0.037)。增加了对侧乳腺的D_(mean)[(1.63±1.26)Gy vs.(0.09±0.05)Gy,P=0.004]。与2F-IMRT计划相比,2F-Rapid Arc治疗时间略有增加[(132.9±7.2)s vs.(140.3±11.6)s,P=0.030],两者的机器跳数相当[(467.0±30.4)MU vs.(494.7±44.9)MU,P=0.094]。结论:2F-Rapid Arc和2F-IMRT计划皆能满足临床需要,2F-Rapid Arc计划比2F-IMRT计划有更好的适形度,更低的高剂量区,但是增加了患侧肺、双肺、心脏的低剂量区及对侧乳腺的平Objective： To compare the dosimetric differences between volumetric modulated arc therapy and intensity modulated radiotherapy for breast cancer patients after breast-conserving surgery. Methods ：Ten patients who received radiotherapy after breast-conserving surgery were selected. Eclipse planning system was used to design volumetric rotating intensity-modulated （2F-RapidArc） and two field intensity- modulated radiation therapy （2F-IMRT） planning for each patient. 2F-RapidArc plans were made using two partial arcs with gantry rotation from 287° -293° to 152° - 162°, and 0° to 90° was avoidance sec-tor. The gantry angle of 2F-IMRT were 301o - 311° and 125.- 1 3 5 .. The prescription dose was 46 Gy/23 fractions. All plans required 95% of the target volume receiving the prescription dose. The dose dis-tribution of the target, organs at risk, machine unit （MU） and treatment time were compared. Results ： 2F-RapidArc and 2F-IMRT plans’ uniformity index was 1. 12 ±0. 02 and 1. 11 ±0. 03 （P =0？ 282）,re- spectively; conformal index was 0. 80 ±0. 03 and 0.65 ±0.04 （P 〈0.001）, respectively. V110 of plan target voiume was 20. 98% ±14.47% and 10.43% ±10.49% （_P= 0.030）, respectively. Comparedwith the 2F-IMRT,2F-RapidArc plans had a higher dosimetric parameters for left lung： V5（48.06% 士 17.32% 仍？ 24.23% ±6. 56%,P =0.001） , V10 （28. 89 ±9.28 低 17. 07 ± 4 .7 8 %, P = 0 ？ 0 0 4 ） , Dmean[ （9. 70 ±2. 14） Gy vs. （6. 86 ± 1. 77 ） Gy, P = 0. 002 ] , increased the double lung; V5 （22.85% ±7.55% 仍？ 11.01% ±2.95%,P =0.001）, V10（ 13.16% ±4.33% 仍？ 7 .7 6% ± 2 .1 6% , P=0.006）, Dmean[（4.66±0.95） Gy vs. （3 . 17 ± 0 . 82） Gy,P = 0 . 001 ] , reduced the left lung; V40 （3.58% ±1.46% vs. 6.19% ±3.04% ,P =0. 006） , reduced the double lung; V40（1 .6 1% ± 0 .6 4% vs. 2.81%±1.39%,P=0. 005） , increased cardiac ： V5 （39. 3% ± 17. 19% vs. 8 .79% ± 4 . 24% ,P 〈 0.001）

关 键 词：乳腺癌 调强放疗 容积旋转调强放疗 剂量学 

分 类 号：R730.55[医药卫生—肿瘤]