心电门控双源CT心脏运动范围的测量及其在降低左侧乳腺癌IMRT中心脏照射剂量的策略

发布时间：2018-05-02 03:02

本文选题：心脏 + 冠状动脉　；参考：《武汉大学》2012年博士论文

【摘要】：第一部分心电门控双源CT心脏及冠状动脉三维运动范围测量目的在放射治疗计划制定中,目标器官移动的定性与定量信息对内脏边界范围的确定非常重要。在左侧乳腺癌的放射治疗中,心脏前壁区域(anterior myocardial territory, AMT),左心室(left ventricle, LV)和冠状动脉不可避免地部分被照射。但是,目前的文献很少描述心脏和动脉的搏动。我们采用心电门控多层螺旋CT测量心脏(包括心脏、心脏前壁区域、左心室)及冠状动脉(包括左右冠状动脉主干、左前降支、左旋支及右缘支)在上下、前后及左右方向上的活动范围,为胸部肿瘤调强放射治疗(intensity-modulated radiotherapy, IMRT)中心脏和冠状动脉等危及器官(organ at risk, OAR)的计划危险体积(planning risk volume, PRV)的勾画提供信息。资料与方法将17例行回顾性心电门控冠脉双源CT检查的正常检查者的图像资料进行分析。分别测量舒张末期和收缩末期两个不同心动周期中心脏、心脏前壁区域、左心室、左右冠脉主干及其主要分支在前后、左右及上下方向上的移动范围。将所得数据应用SPSS16.0软件包进行分析,得出心脏不同部位,左右冠脉主干及主要分支的三维运动范围的均值。结果对于心脏,心脏前壁区域和左心室前界、右界的运动范围约3-5mm,左界和后界的运动范围约5-8mm,上界和下届的运动范围约5-6mm,其中心脏前壁区域和左心室的左界、后界和下届的运动范围最大,大部分方向上的运动范围约4-7mm。对于冠状动脉,前后方向的运动范围4mm,左右方向的运动范围约4-7mm,上下方向的运动范围约4-6mm。结论心脏和冠状动脉各部分在心动周期中的运动范围不一致,心脏前壁区域和左心室的左界、后界和下届的运动范围最大,左冠状动脉比右冠状动脉的活动范围大。心脏、心脏前壁区域和冠状动脉在各个方向上多有4-7mm的运动范围。第二部分心脏和冠状动脉运动补偿降低左侧乳腺癌调强放射治疗中心脏及冠脉照射剂量的策略目的探讨将心脏、心脏前壁区域、左心室和左右冠脉主干及其主要分支作为危及器官并将第一部分测得的心脏及冠状动脉三维运动范围的数据应用于制订左乳腺癌调强放射治疗中危及器官和计划危险体积PRV的勾画中,能否有效降低左侧乳腺癌IMRT计划中心脏前壁区域及冠脉的照射剂量。资料与方法在放射治疗计划数据库挡案中随机选择早期乳腺癌行保乳手术治疗后的21例患者的计划CT图像,定位CT扫描体位与治疗体位相同(仰卧位,双手置于头顶),扫描范围由下颈部至上腹部,层厚2.5mm。由同一放疗医师勾画靶区和危及器官OAR。靶区包括临床靶区(clinical target volume, CTV)和计划靶区(planning target volume, PTV)。CTV为整个左侧乳腺组织,其前界位于皮下0.5cm；PTV为CTV外放0.8cm。为了计算所有危及器官的照射剂量,将左冠状动脉主干(left coronary artery, LCA)、右冠状动脉主干(right coronary artery, RCA)及左前降支(left anterior descending,LAD)、左旋支(left circumflex artery, LcxA)、右缘支(right marginal artery, RMA)增加为OARs。将第一部分测得的心脏、心脏前壁区域、左心室、左右冠脉主干及其主要分支在心动周期中的活动范围作为这些危及器官PRV外放边缘的依据。选择两种不同的治疗计划IMRT(H)和IMRT (AMT), IMRT (H)是将心脏作为危及器官,IMRT (AMT)是将心脏前壁区域代替心脏作为危及器官。由TPS获得剂量体积参数Dmean和D2%,Dmean指平均剂量,D2%指危及器官2%体积接受最大剂量照射时的剂量。所有统计学处理均采用SPSS16.0统计学软件包,各个危及器官的参数采用配对t检验,以P0.05为有统计学意义。结果根据第一部分所测得的危及器官(包括心脏、心脏前壁区域、左心室、左冠状动脉、右冠状动脉、左前降支、左旋支和右缘支)的活动范围,确定相应危及器官计划危险体积的外放边缘,这些外放边缘具体数值如表2.1所示。与危及器官的体积相比,心脏、心脏前壁区域和左心室的PRV分别增加了50.6%±7.9%(95%CI:33%-61%),194.9%±36.4%(95%CI:149.0%-290.0%),76.7%±9.8%(95%CI:56%-91%),而左冠状动脉、右冠状动脉、左前降支、左旋支和右缘支的PRV增加了18.7-42.6倍,如表2.2所示。IMRT(H)和IMRT(AMT)中所有危及器官的Dmean和D2%均在表2.2中。比较心脏作为危及器官的PRV的Dmean, IMRT(H和IMRT(AMT)计划中分别增加了5.52%(P0.05)和5.81%(P0.05)；将AMT作为危及器官时,其PRV的Dmean减少了8.35%(P0.05),如图2.1A、2.1C所示。同样地,比较危及器官的D2%,IMRT(H)计划中LV, LCA, RCA, LAD, LcxA和RMA等大约增加了10%-21%(all the P0.05),如图2.1B所示；IMRT(AMT)计划中心脏、心脏前壁区域、左心室和左前降支的D2%增加了22-43%(P0.05),如图2.1D。 IMRT(AMT)计划中的平均剂量Dmean和D2%和IMRT(H)计划比较,心脏、心脏前壁区域、左心室和它们的PRV的平均剂量分别下降了14-16%,26-33%,19-23%(所有P0.05)；左前降支LAD和PRV的Dmean分别下降了15%,14%(P0.05),如图2.1E、2.1G所示。同样地,心脏、心脏前壁区域、左心室、左前降支和其PRV的D2%分别大约下降了13%-26%,18%-23%18%-31%,3%-15%(所有P0.05),如图1F、1H所示。并且左旋支PRV的Dmean下降了13.7%(P0.05)。如图2.1G所示。与将心脏和AMT作为危及器官的乳腺IMRT计划相比,将心脏、AMT、LV、 LAD作为危及器官的IMRT计划的Dmean和D2%分别降低了15-33%、13-31%,两种计划方法间的差别具有统计学意义(所有P0.05)。结论第一部分测得的心脏,AMT, LV, LCA, RCA, LAD, LcxA和RMA的运动范围可以为这些危及器官的PRV外放边缘作为参考,从而更准确的勾画危及器官的计划危险体积。心脏和冠状动脉运动补偿以及将AMT、LV、LAD、RCA等作为危及器官的乳腺IMRT计划比常规IMRT计划能更进一步降低心脏和冠脉的照射剂量。
[Abstract]:Part 3 measurement of three-dimensional motion range of cardiac and coronary arteries by dual gated ECG gated CT
Objective in the formulation of radiotherapy planning, the qualitative and quantitative information of target organ movement is very important for determining the visceral boundaries. In the radiotherapy of left breast cancer, the anterior myocardial territory (AMT), the left ventricle (left ventricle, LV) and the coronary arteries are inevitably partially irradiated. The previous literature rarely describes the pulsation of the heart and arteries. We use ECG gated multislice CT to measure the heart (including the heart, the anterior wall area, the left ventricle) and the coronary artery (including the left and right coronary arteries, the left anterior descending branch, the left circumflex, and right margin) in the upper and lower, the back and right direction, and to strengthen the chest tumor. Information is provided for the planned risk volume (planning risk volume, PRV) of endanger organs (organ at risk, OAR), such as the central organs of intensity-modulated radiotherapy (IMRT) and the coronary artery, and the coronary artery (organ at risk, OAR).
Materials and methods the image data of 17 normal examiners of a retrospective ECG gated coronary dual source CT examination were analyzed. The heart, the anterior wall region of the heart, the left ventricle, the left and right main arteries and their main branches were measured in the two different cardiac cycles at the end of diastolic and late systolic stage. The data were analyzed by SPSS16.0 software package, and the mean values of three dimensional motion range of different parts of the heart, left and right coronary arteries and main branches were obtained.
Results for the heart, the region of the anterior wall of the heart and the front of the left ventricle, the movement range of the right boundary is about 3-5mm, the movement range of the left and the posterior boundaries is about 5-8mm, and the upper and next movement ranges about 5-6mm, of which the anterior and left ventricle, the left and the left ventricles of the heart are the largest, and the range of movement in most directions is about 4-7mm. for the crown. The movement range of the artery is 4mm, the motion range of the left and right directions is about 4-7mm, and the range of motion is about 4-6mm.
Conclusions the range of movement of the cardiac and coronary arteries in the cardiac cycle is not consistent. The anterior and left ventricle, the left and the left ventricles of the heart are the largest, and the left coronary artery is more active than the right coronary artery. The heart, the anterior wall area and the coronary arteries have more 4-7mm range in each direction.
The second part is cardiac and coronary artery motion compensation to reduce the dose of central and coronary artery in intensity-modulated radiation therapy for left breast cancer.
Objective to investigate whether the heart, the anterior wall of the heart, the left ventricle and the main branches of the left and right coronary arteries and their main branches are used as endanger organs and the data of the three-dimensional motion of the heart and coronary arteries measured in the first part should be used to draw up the delineation of the risk of organs and the planned risk volume of PRV in the intensity modulated radiation therapy of left breast cancer, and can be effectively reduced. The radiation dose of the anterior wall area and the coronary artery in the IMRT center of the left breast cancer.
Materials and methods the planned CT images of 21 patients with early breast cancer after breast conserving surgery were randomly selected in the radiation therapy program database. The position of the CT scanning body was the same as that of the treatment position (supine position, hands on the top of the head), the scan range from the lower neck to the upper abdomen, and the thickness of 2.5mm. by the same radiation therapist to delineate the target area and danger. The target area of OAR., including the clinical target area (clinical target volume, CTV) and the planned target area (planning target volume, PTV).CTV is the whole left mammary gland, and its front is located in the subcutaneous 0.5cm. The right coronary artery (RCA) and the left anterior descending branch (left anterior descending, LAD), the left lateral branch (left circumflex artery, LcxA) and the right marginal branch were added to the heart, the anterior wall region of the heart, the left ventricle, the left and right trunk of the coronary artery and its main branches in the cardiac cycle. The dynamic range is the basis for the endanger of the outer edge of the organ PRV. Two different treatment plans, IMRT (H) and IMRT (AMT), IMRT (H), are used to replace the heart as a endanger organ. IMRT (AMT) is the replacement of the heart of the heart as a endanger organ. The dose volume parameter Dmean and D2% are obtained by TPS. All the statistical treatments were carried out by SPSS16.0 statistics package, and the parameters of each organ were measured by paired t test, and P0.05 was statistically significant.
Results the range of activity of endanger organs (including the heart, the region of the anterior wall of the heart, the left ventricle, the left coronary artery, the right coronary artery, the left anterior descending branch, the left circumflex, and the right marginal branch) was determined to determine the outer edge of the corresponding risk volume of the organ that endanger the organ, as shown in Table 2.1, as shown in Table 2.1. The PRV of the heart, the anterior wall area and the left ventricle increased by 50.6% + 7.9% (95%CI:33%-61%), 194.9% + 36.4% (95%CI:149.0%-290.0%), 76.7% + 9.8% (95%CI:56%-91%), while the left coronary artery, the right coronary artery, the left anterior descending branch, the left and right branch PRV increased 18.7-42.6 times, as shown in table 2.2,.IMRT (H) and IMRT (AMT) all Dmean and D2%, which endanger organs, are in table 2. 2. Compared to the Dmean of PRV that endanger organs, IMRT (H and IMRT (AMT) plan increased by 5.52% (P0.05) and 5.81% (P0.05), respectively, while AMT as an organ endangering the organ, the PRV is reduced by 8.35%. LCA, RCA, LAD, LcxA, and RMA have increased approximately 10%-21% (all the P0.05), as shown in figure 2.1B; the IMRT (AMT) planning center, the anterior wall area of the heart, the left ventricle and the left anterior descending branch increased.
In the IMRT (AMT) plan, the average dose of Dmean and D2% and IMRT (H) plan were compared. The average dose of the heart, the anterior wall area, the left ventricle and their PRV decreased respectively 14-16%, 26-33%, 19-23% (P0.05), and the left anterior descending LAD and D2%, respectively, decreased by 15%, respectively, as shown in the heart and the anterior wall area. The left ventricle, the left anterior descending branch and the D2% of its PRV decreased by about 13%-26%, 18%-23%18%-31%, 3%-15% (all P0.05), as shown in Fig. 1F, 1H, and Dmean of the left-handed PRV decreased by 13.7% (P0.05). As shown in picture 2.1G.
Comparing heart, AMT, LV, and LAD as the IMRT plan for organ threatening IMRT, Dmean and D2% reduced 15-33% and 13-31%, respectively, compared with the heart and AMT as an organ - threatening mammary gland plan. The difference between the two planning methods was statistically significant (all P0.05).
Conclusion the first part of the heart, AMT, LV, LCA, RCA, LAD, LcxA, and RMA can be used as a reference for the peripheral PRV that endanger the organs as a reference, and thus more accurately delineates the planned dangerous volume of organs that endanger the organs, cardiac and coronary artery motion compensation, and AMT, LV, LAD, RCA, and so on as the mammary gland plan for endanger organs. The conventional IMRT plan can further reduce the radiation dose of the heart and coronary arteries.

【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R737.9;R730.44

【参考文献】