摘要
目的比较早期乳腺癌保乳术后动态调强放疗(intensity modulated radiotherapy,IMRT)与常规放疗(conventional radiotherapy,CRT)的剂量学分布,为IMRT在乳腺癌保乳术后放疗中的应用提供依据。方法选取12例保乳术后乳腺癌患者,针对每个患者分别设计IMRT计划和CRT计划,处方剂量均为50 Gy/25次,利用剂量体积直方图(DVH图)比较两种计划的靶区和危及器官的剂量学差异。结果两种计划中95%等剂量曲线包绕计划靶区的体积相似,分别为98.22%和98.76%(P>0.05);IMRT计划计划靶区的V105%、V110%分别为12.86%、1.02%低于CRT计划的44.56%、6.37%(P<0.05);IMRT计划计划靶区的CI值由0.55提高至0.68,HI值由1.15降至1.09(P<0.05)。与CRT计划相比,IMRT计划患侧肺V30、V20分别降低了3.68%和5.75%,同时肺平均剂量(MLD)由9.24 Gy下降至7.12 Gy(P<0.05);IMRT计划将左侧乳腺癌患者心脏V30、V40和V50分别降低了5.99%、5.68%和1.68%(P<0.05)。结论 IMRT相比CRT在保证靶区覆盖率的同时,减少了高剂量的照射,改善了靶区剂量分布的均匀性,同时降低了周围正常器官的照射剂量。
Objective To compare the dosimetry distribution between conventional radiotherapy （CRT） and intensity modu- lated radiation therapy （IMRT） after breast - conserving surgery in early - stage breast cancer , and provide evidence for the application of IMRT in patients. Methods Twelve patients with early - stage breast cancer, who received breast conserving surgery, were selected in this study. CRT and IMRT plans with prescribed dose of 50 Gy/25 f were designed for each patient. The Dose volume histograms （DVHs） were used to evaluate the dosimetric distribution of the plan target volume （PTV） and the organs at risk （ OARs ） between the two plans. Results The Vg95% of PTV was similar in the two plans （ 98.22% vs 98.76% ） ; The V105% ,V110% of PTV in IMRT plans was 12.86% ,1.02% versus 44.56% ,6.37% in CRT plans（P 〈 0.05 ） ; The conformity .index（CI） in IMRT plans was increased from 0.55 to 0.68, while the homogeneity index（HI） was decreased from 1.15 to 1.09 （P 〈 0.05 ）. Compared to CRT plans, the V30 and V20 of the ipsilateral lung in IMRT plans was reduced by 3.68% and 5.75%, the mean lung dose（MLD） was decreased from 9.24 Gy to 7.12 Gy（P 〈 0.05 ） ; In the left side pa- tients, the V30 ,V40 and V50 of the heart in IMRT plans was reduced by 5.99% ,5.68% and 1.68% , respeetivly（P 〈0.05）. Conclusion Compared to CRT, IMRT decreased the high dose volume and improved the dose homogeneity with a satisfactory target coverage and effectively reduced the radiation dose for normal organs such as the heart and lungs.
出处
《中国辐射卫生》
2014年第1期57-59,63,共4页
Chinese Journal of Radiological Health
基金
吉林省自然科学基金项目(20110473)
关键词
乳腺癌
保乳治疗
常规放射治疗
调强放射治疗
Breast Cancer
Breast - Conserving Surgery
Conventional Radiotherapy
Intensity Modulated Eadiation Thera-PY
