乳腺癌保乳术后切线野照射与瘤床同步整合补量调强放射治疗的剂量学区别  

Dosimetric Differences between Conventional Tangential Irradiation and SIB-IMRT after Breast-conserving Surgery of Breast Cancer

作　　者：李楠[1] 李光[1] 赵欣宇[2] 张硕[1] 夏兵[1] 王志宇[1] 

机构地区：[1]中国医科大学附属第一医院放疗科,沈阳110001 [2]中国医科大学94期七年制临床医学专业,沈阳110001

出　　处：《中国医科大学学报》2011年第7期635-638,共4页Journal of China Medical University

摘　　要：目的评价瘤床同步整合补量调强放射治疗(SIB-IMRT)在乳腺癌保乳术后放射治疗中的剂量学优势。方法选择45例保乳术后的乳腺癌患者,利用三维治疗计划系统为每例患者分别设计切线野照射计划与SIB-IMRT计划2种放射治疗计划。在剂量体积直方图(DVH)上比较靶区覆盖率、靶区内剂量分布均匀性,计划靶体积(PTV)和危及器官(OARs)在2种计划中的剂量学差异,进行统计学分析。结果 SIB-IMRT技术的瘤床区和全乳靶区覆盖率,与切线野照射技术相似,分别为99.5%和99.2%,99.1%和98.6%。与切线野技术相比较,SIB-IMRT计划中左侧乳腺癌患者心脏的平均剂量(Dmean)从769.12cGy减少到425.12Gy;患侧肺的Dmean、至少接受20Gy照射的体积百分比(V20)分别从1586.67cGy减少到1125.77cGy、从27.3%到21.4%;对侧乳腺的Dmean从73.5cGy减少到21.2cGy。结论与切线野照射技术相比,SIB-IMRT技术的剂量学优势在于:在保证靶区覆盖率的前提下,降低了OARs的受照射剂量与容积,减少了总的治疗时间。Objective To evaluate the dosimetric benefits of the simultaneous integrated boost intensity-modulated radiation therapy （SIB-IMRT） after breast-conserving surgery of breast cancer.Methods 45 patients who had received breast-conserving surgery were selected.Each patient was given two plans by three dimensional treatment planning system：SIB-IMRT plan and conventional tangential irradiation plan.Dosimetric comparisons of PTV and OARs between the two plans were performed on each patient by DVH.The data were analyzed statistically.Results The PTV1 and PTV2 coverages in SIB-IMRT plan were similar to those of the conventional plan （99.5% vs.99.2% and 99.1% vs.98.6%）.Compared to the conventional plan,obvious reduction in the doses of OARs was achieved in SIB-IMRT plan：the mean dose （Dmean） of heart decreased from 769.12 cGy to 425.12 cGy;the Dmean of ipsilateral lung decreased from 1586.67 cGy to 1 125.77 cGy,while percentage of volume receiving more than 20 Gy （V20） decreased from 27.3% to 21.4%;the Dmean of contralateral breast decreased from 73.5 cGy to 21.2 cGy.Conclusion SIB-IMRT maintains a good coverage of PTV,and reduces the exposure dose and volume of OARs as well as the overall therapeutic time.

关 键 词：乳腺癌 保乳治疗 瘤床同步整合补量调强放射治疗 

分 类 号：R737.9[医药卫生—肿瘤]