摘要
目的探讨应用四维CT(4D-CT)在左侧乳腺癌保乳术后调强放疗(IMRT)的剂量优势。方法选择左侧乳腺癌保乳手术后IMRT患者18例,在自由呼吸状态下进行常规三维CT(3D-CT)和4D-CT扫描并采集图像,分别勾画靶区和危及器官(OAR),观察左肺及心脏的受量。在3D-CT图像上制定逆向IMRT计划,将3D-CT图像的IMRT计划复制到4D-CT的CT0%(吸气末)和CT50%(呼气末)时相上,比较3D-CT与4D-CT的CT0%(吸气末)、CT50%(呼气末)计划靶区及保护器官的剂量学差异。结果3D-CT时计划靶区(PTV)的D95、D90、Dmean与4D-CT0%时PTV的D95、D90、Dmean比较,差异均无统计学意义(Z=-0.92,P=0.36;Z=-0.26,P=0.79;t=0.04,P=0.97);3D-CT时PTV的D95、D90、Dmean与4D-CT50%时PTV的D95、D90、Dmean比较,差异均无统计学意义(Z=-1.50,P=0.13;Z=-0.43,P=0.67;t=2.02,P=0.06)。3D-CT时的左肺及心脏的V5、V10、V20、Dmean均高于4D-CT0%时的左肺及心脏V5、V10、V20、Dmean,且差异均有统计学意义(P<0.05)。结论4D-CT在吸气末时相更能降低左肺及心脏的受量。
Objective To investigate the dosimetric advantages of four-dimensional CT(4D-CT)in intensity modulated radiation therapy(IMRT)after breast conserving surgery for left breast cancer.Methods Eighteen patients with IMRT after breast-conserving surgery for left breast cancer underwent conventional three-dimensional CT(3D-CT)and 4D-CT scans under free breathing,and the images were collected.The target area and organs at risk(OAR)were delineated respectively.The left lung and heart were observed.Inverse IMRT plans were made on 3D-CT images,and the IMRT plans of 3D-CT images were copied to the phases of CT0%(end of inspiration)and CT50%(end of expiration).The dosimetric differences between 3D-CT and 4D-CT in target area and protective tube were compared.Results There were no significant difference in D95,D90,Dmean of PTV between 3D-CT and 4D-CT0%in D95,D90 and Dmean of PTV(Z=-0.92,P=0.36;Z=-0.26,P=0.79;t=0.04,P=0.97);there were no significant difference in D95,D90,Dmean of PTV between 3D-CT and 4D-CT50%in D95,D90 and Dmean of PTV(Z=-1.50,P=0.13;Z=-0.43,P=0.67;t=2.02,P=0.06).The V5,V10,V20 and Dmean of left lung and heart in 3D-CT were higher than those in 4D-CT0%,V5,V10,V20 and Dmean of left lung and heart in 3D-CT were higher than those in 4D-CT0%,and the difference was statistically significant(P<0.05).Conclusion 4D-CT can reduce the dose of left lung and heart at the end of inspiratory phase.
作者
唐成琼
陈春丽
刘浩
曹耀峰
刘江平
艾秀清
TANG Chengqiong;CHEN Chunli;LIU Hao;CAO Yaofeng;LIU Jiangping;AI Xiuqing(Department of Radiophysics,Oncology Hospital,Third Clinical Medical College of Xinjiang Medical University,Urumqi,Xinjiang 830011,China;Department of Breast Radiotherapy,Oncology Hospital,Third Clinical Medical College of Xinjiang Medical University,Urumqi,Xinjiang 830011,China)
出处
《重庆医学》
CAS
2020年第19期3248-3251,共4页
Chongqing medicine
基金
新疆维吾尔自治区科技支疆项目(2017E0260)。
关键词
4D-CT
乳腺癌
保乳术后
调强放疗
剂量学
吸气末
呼气末
4D-CT
breast cancer
breast conserving surgery
intensity-modulated radiotherapy
dosimetry
end-inspiratory
end-expiratory
