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.
作者
李倩
尹勇
佟颖
魏鸿
程品晶
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)
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
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）
关键词
乳腺癌
调强放疗
左心室肌
左前降支
剂量评估
Breast carcinoma
Intensity modulated radiotherapy
Left ventricular myocardial
Left anterior descending
Dose evaluation
