乳腺癌亚临床肿瘤剂量分割优化的实验研究  

Experimental study on optimized fractionated radiation schedule for subclinical breast cancer

作　　者：万爱英[1] 许新[1] 杨伟志[1] 

机构地区：[1]北京协和医学院中国医学科学院肿瘤医院放疗科,100021

出　　处：《中华放射肿瘤学杂志》2014年第6期540-543,共4页Chinese Journal of Radiation Oncology

基　　金：首都临床特色应用研究基金资助（D101100050010062）.志谢 照射所需物理参数由张红志教授实测、规划

摘　　要：目的 筛选乳腺癌亚临床肿瘤相对优化剂量分割方案.方法 采用人乳腺癌裸小鼠移植瘤亚临床肿瘤为实验模型,细胞接种后72 h进行常规分割（200 cGy/次、1次/d、5次/周）,超分割（160 cGy/次、2次/d、间隔6h、10次/周）,大分割（300 cGy/次、1次/d、5次/周,400 cGy/次、隔天1次、3次/周）照射,总剂量为40、60 Gy.观察指标成瘤率、近期肿瘤控制率、远期肿瘤控制率等.对各实验组测量数据差异行Х^2检验.结果 总剂量40 Gy时（接种细胞数1.5 ×10^5,空白对照组成瘤率为2/8）,超分割方案是相对优化方案.总剂量60 Gy时（接种细胞数3.1 ×10^5,空白对照组成瘤率为11/11）,大分割300 cGy 5次/周最优（P =0.001）,其中常规分割组近、远期肿瘤控制率均为0（成瘤率均为8/8）,超分割组近、远期肿瘤控制率分别为50％、25％（成瘤比率分别为4/8、6/8）,大分割400cGy 3次/周组近、远期肿瘤控制率均为25％（成瘤率均为6/8）,大分割300 cGy 5次/周组近、远期肿瘤控制率均为67％（成瘤率均为4/12）.结论 接种细胞数不同,控制亚临床肿瘤所需分割方案及总剂量不同.当成瘤率为100％时,就远期控制而言,300 cGy 5次/周是相对优化方案.Objective To determine the optimized fractionated radiation schedule by comparing the dose-response relationship between different fractionated radiation schedules with a total dose of 40 Gy or 60 Gy in subclinical breast tumor.Methods Balb/c nude mice bearing subclinical human breast cancer （injected subcutaneously into the hind legs with 1.5 × 10^5 or 3.1 × 10^5 exponentially growing MCF-7 cells） were assigned randomly to blank control group （without radiation）,conventionally fractionated radiation group （200 cGy,once daily,10 times/week）,hyperfractionated radiation group （160 cGy,twice daily with an interval of 6 h,5 times/week）,first hypofractionated radiation group （300 cGy,once daily,5 times/ week）,and second hypofractionated radiation group （400 cGy,once every other day,3 times/week） ;the total dose was 40 Gy or 60 Gy.The measurement indices were tumor formation rate,short-term tumor control rate,long-term tumor control rate,the time of tumor recurrence,and the maximum diameter of the bottom of tumor.The observation lasted 24 weeks.Data were compared between these groups by chi-square test.Results With a total dose of 40 Gy （the number of injected cells was 1.5 × 10^5,the tumor formation rate of the blank control group was 2/8）,hyperfractionated radiation was the optimized schedule.With a total dose of 60 Gy （the number of injected cells was 3.1 × 10^5,the tumor formation rate of the blank control group was 11/11）,the first hypofractionated radiation （300 cGy,once daily,5 times/week） was the optimized schedule （P =0.001）;the short-term and long-term tumor control rates of the conventionally fractionated radiation group,hyperfractionated radiation group,second hypofractionated radiation group,and first hypofractionated radiation group were 0/0 （tumor formation rates：8/8 and 8/8）,50%/25% （tumor formation rates：4/8 and 6/8）,25 %/25 % （tumor formation rates：6/8 and 6/8））,and 67 %/67 % （tumor formation rates：4/12 and 4/12）,respectively.Conclu

关 键 词：剂量分割方案优化 乳腺癌亚临床肿瘤 裸小鼠移植瘤 

分 类 号：R737.9[医药卫生—肿瘤]