左侧乳腺癌调强放疗中心跳对左心室肌及左前降支剂量评估的影响  

The impact of heartbeat on the left ventricular myocardial and the left anterior descending coronary arterial dosimetry following intensity modulated radiotherapy for left-sided breast cancer

作　　者：李倩 尹勇 佟颖 魏鸿 程品晶[1] 巩贯忠 Li Qian;Yin Yong;Tong Ying;Wei Hong;Cheng Pinfing;Gong Guanzhong(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China;Department of Radiation Physics,Shandong Cancer Hospital Affiliated to Shandong University,Jinan 250117,China)

机构地区：[1]南华大学核科学技术学院,衡阳421001 [2]山东大学附属山东省肿瘤医院放射物理技术科,济南250117

出　　处：《中华放射医学与防护杂志》2018年第10期747-750,共4页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金（81301936）;山东省重点研发计划（2018GSF118048）

摘　　要：目的 研究左侧乳腺癌调强放射治疗（IMRT）中，心跳对左心室肌（mLV）及左前降支（LAD）剂量评估的影响。方法 选取15例女性患者平静吸气屏气下的心电门控（ECG-gated）4D-CT图像，参照心动周期以5%间隔进行图像重建，重建0~95%共20个时相的图像。分别勾画mLV及LAD。基于0%时相的图像进行左侧乳腺癌IMRT计划设计。统计各时相mLV的体积并计算相似性指数（dice similarity coefficient，DSC）；计算LAD及mLV剂量-体积指标的变化范围。结果 mLV的DSC变化率最大可达472.07%，其平均变化率约为体积变化率的8倍。mLV的体积与DSC在最大、最小值之间差异均具有统计学意义（t=-6.585、-28.870，P〈0.05）。mLV的平均剂量（Dmean）变化率最高可达41.95%。mLV的Dmean、V10、V20、V30、V40在最大、最小值之间差异均有统计学意义（t=-5.260、-4.084、-3.592、-3.273、-2.566，P〈0.05）。LAD的Dmean平均变化率最高可达130.14%。LAD的Dmean、V10、V20、V30、V40在最大、最小值之间差异均有统计学意义（t=-9.758、-8.810、-8.682、-7.853、-6.205，P〈0.05）。结论 左侧乳腺癌放疗中，心跳对mLV和LAD的剂量评估影响不容忽视。Objective To study the impact of heartbeat on the left ventricular myocardial （mLV） and the left anterior descending （LAD） coronary arterial dosimetry following intensity modulated radiotherapy （IMRT） for left-sided breast carcinoma. Methods A total of 15 female patients who received electrocardiography gated 4D-CT scan in inspiratory breathing-holding were enrolled. According to cardiac cycle, 20 time-phase images were reconstructed from 0 to 95% at 5% interval. Then, the mLV and the LAD were delineated respectively and the IMRT plans of the left breast carcinoma were generated based on 0% phase CT images. The volume and dice similarity coefficient （DSC） of the mLV were calculated, and the variation range of the mLV and the LAD dose-volume indexes were compared among different phases. Results The average rate of DSC variation of mLV was eightfold of volume, which reached to 472.07%,and the average change rate of mLV （Dmean） was up to 41.95%. The difference of the mLV＇s volume and DSC was statistically significant between the maximum and minimum（t=-6.585, -28.870, P〈0.05）, as well as the Dmean, V10, V20, V30 and V40（t=-5.260, -4.084, -3.592, -3.273, -2.566, P〈0.05）. The average change rate of the LAD＇s Dmean was up to 130.14%. The difference of Dmean, V10, V20, V30 and V40 of LAD was statistically significant between the maximum and minimum（t=-9.758, -8.810, -8.682, -7.853, -6.205,P〈0.05）. Conclusions The dosimetry impact of heartbeat on mLV and LAD should not be ignored.

关 键 词：乳腺癌 调强放疗 左心室肌 左前降支 剂量评估 

分 类 号：R737.9[医药卫生—肿瘤] R730.55[医药卫生—临床医学]