【作者】 樊伶俐；

【导师】 王捷；

【作者基本信息】 广西医科大学 ， 肿瘤学， 2012， 硕士

【摘要】 目的：探讨用64排螺旋CT行冠状动脉血管成像(CTA)方法对左乳癌保乳术后患者心脏亚结构的显示和勾画的可行性；比较俯卧位和仰卧位两种体位下乳腺癌调强放射治疗(IMRT)的靶区和正常组织剂量学的差异。方法：2011年1月至12月10例左乳癌保乳术后患者进入本研究。用CTA方法对每例病人分别做俯卧位和仰卧位的定位扫描。每个体位同时做两个序列扫描,一个是常规序列,另一个是特殊序列(CTA)。将两个序列的CT图像传输到Master Plan放疗计划系统进行融合。在常规序列上勾画出全乳的临床靶体积(CTV)、计划靶体积(PTV)、双侧肺(L-Lung、R-Lung)、脊髓(Spinal Cord)、对侧乳腺(R-Breast)、心脏(Heart);在特殊序列上勾画出左心室(LV)、冠状动脉左前降支(LAD)及LAD-计划的危及器官体积(LAD-PRV)(LAD外扩1cm形成)。每例病人制定仰卧位和俯卧位两种IMRT计划,共20个计划。在DVH图上比较以下指标：PTV:Dmean、D95；同侧肺(L-Lung):Dmean、 V5、V20; Heart及其亚结构(LAD-PRV、 LV):Dmean、V10、V20、V25、V30、V40;对侧肺(R-Lung):Dmean、 V5; R-breast:Dmax、Dmean。结果：CTA勾画心脏亚结构的方法非常直观,易于勾画,且经济可行,值得推广。仰卧位和俯卧位PTV的剂量都达到了放疗计划的要求,分布可,差异无统计学意义。俯卧位计划明显降低了LAD-PRV、LV、心脏和同侧肺的受照剂量。LAD-PRV的Dmean降低了445.83cGy(P=0.043),V25降低了8.57%(P=0.042)；LV的Dmean降低了575.00cGy(P=0.003),V20降低了15.21%(P=0.026),V25降低了12.54%(P=0.042)；Heart的Dmean降低了402.00cGy(P=0.039),V10降低了28.31%(P=0.029),V20降低了12.59%(P=0.011),V25降低了8.70%(P=0.019),V30降低了5.54%(P=0.034)；L-Lung的Dmean降低了553.33.00cGy(P=0.004),V05降低了27.86%(P=0.031),V20降低了10.62%(P=0.006)。结论：1.利用64排CT冠状动脉血管成像勾画心脏亚结构的方法非常直观,易于勾画,且经济可行,值得推广。2.对乳腺大小适中的大多数保乳术后的亚洲女性,俯卧位较仰卧位IMRT放疗能减少同侧肺、心脏及其亚结构的受照剂量,从而可能降低放疗后心血管事件的发生率。3.对于心脏亚结构如LV、LAD的剂量-体积限制的具体值,需要进一步探讨。更多还原

【Abstract】 Objective:To evaluate the feasibility that64-slice spiral CT coronary angiography(CTA) method display and outline sub-structure of the heart in patients of left breast-conserving surgery; and compare the dosimetry differences between target and organs at risk under the prone and supine two kinds of position in breast intensity-modulated radiation therapy.Methods:From January to December in2011,20patients of left breast-conserving surgery were enrolled. The CTA method was used separately for each patient prone and supine position scanning. Two sets of sequence scanning were done at the same time. One is a conventional sequence, the other is a special sequence (CTA). CT images of the two sequences were transmitted to the Master Plan radiation planning system for integrated. On the conventional sequence, the clinical target volume (CTV) of the whole breast, planning target volume (PTV), bilateral lung (L-Lung, R-Lung), spinal cord, the contralateral breast (R-Breast) and Heart were outlined; On the special sequence, left ventricular (LV), left anterior descending coronary artery (LAD) and LAD’s planning risk volume (LAD-PRV)(LAD1cm outside the expanded form) were outlined. For each patient, two kinds of IMRT plans were developed under supine and prone position, a total of20plans. In the dose-volume histogram, the following indicatorswas compared:PTV:Dmean, D95; the ipsilateral lung(L-Lung):Dmean, V5, V20; heart and its sub-structures(LAD-PRV、LV): Dmea、V10、V20、V30、V40; the contralateral lung(R-Lung):Dmean> V5; R-breast:Dmax、Dmean.Results:CTA method outline sub-structure of the heart is very intuitive, easy to sketch, economic and worthy of promotion. PTV’s dose has reached the radiation treatment planning requirements both in the supine and prone position.The dose distribution of the two positions is recognized. PTV’s dose of the two positions has no significant.The plans of prone position significantly reduced the exposure doses of LAD, LV, heart and the ipsilateral lung. LAD-PRV’s Dmean reduced445.83cGy (P=0.043),V25reduced8.57%(P=0.042); LV’s Dmean reduced575.00cGy (P=0.003), V20reduced15.21%(P=0.026), V25reduced12.54%(P=0.042);Heart’s Dmean reduced402.00cGy (P=0.039),V10reduced28.31%(P=0.029), V20reduced12.59%(P=0.011), V25reduced8.70%(P=0.019), V30reduced5.54%(P=0.034);L-Lung’s Dmean reduced553.33.00cGy (P=0.004),V05reduced27.86%(P=0.031),V20reduced10.62%(P=0.006)Conclusion:1. The method that CTA outlines sub-structure of the heart is very intuitive, easy to sketch, economic and worthy of promotion.2.For most Asian women with medium size of breast after BCT, comparing with supine position, prone position IMRT radiation can reduce the ipsilateral lung’s, heart’s, and its sub-structure’s exposure doses, which may reduce the incidence of cardiovascular events after radiotherapy.3.The dose-volume limit value of the sub-structure of the heart such as LV、LAD need to be further explored.更多还原