摘要目的 探讨PET-CT对左侧乳腺癌术后放疗患者左心室(LV)显示和心脏亚结构[LV及左侧冠状动脉前降支(LAD)]勾画,以及心脏、心脏亚结构放疗剂量体积间关系.方法 2008-2009年间14例左侧乳腺癌患者进入本研究,放疗前接受氟脱氧葡萄糖PET-CT LV心肌显像扫描,继而用ADAC Pinnacle37.6c计划系统与增强定位CT融合.LV在PET-CT图像上勾画,LAD的勾画参考前室间隔解剖及增强CT图像.放疗计划采用6个野简化调强放疗(sIMRT)技术,并用Pearson法分析sIMRT下心脏与亚结构接受≥50%处方剂量(25 Gy)的体积占总体积百分比(V25)间关系.结果 14例患者PET-CT图像勾画的LV体积(LV-PET)均值为112.931 cm3.心脏V25与LV-PET V25间呈正相关(R=0.869,P=0.000),心脏V25与LAD-CTVV间无关(R=0.220,P=0.440).结论 对左侧乳腺癌患者以PET-CT LV代谢显像为基础能有效勾画LV解剖结构,sIMRT计划显示了心脏与其亚结构的剂量体积间关系,为进一步分析这些正常组织的放射损伤提供了量化的基础和可能.

abstractsObjective To evaluate the volume of left ventricle (LV) based on PET-CT in left-sided breast cancer patients treated with adjuvant radiotherapy. To assess the impact of dose and volume in interrelations for heart and cardiac sub-structures using dose-volume histograms. Methods From October 2008 to February 2009, 14 patients with post-operatively confirmed left-sided breast cancer were enrolled in this study. Patients were scanned using contrast enhanced CT for simulation and FDG PET-CT have been applied to display the structure of left ventricle in each patient before radiotherapy (RT). The LV has been delineated based on PET-CT. Other critical sub-structures, such as left anterior descending coronary artery (LAD) have been contoured in each patient. The six-field simple intensity modulated radiotherapy (slMRT)technique has been created in all patients. Results The mean volumes of left ventricle based on PET-CT (LV-PET) were 112. 931 cm3. The volume of LV receiving ≥50% prescription dose highly correlated with the volume of heart receiving ≥50% prescription dose (R = 0. 869, P = 0. 000). There was less correlation between the volume of LAD and the volume of heart receiving ≥ 50% prescription dose ( R = 0. 220, P =0. 440). Conclusions The left ventricle could be delineated efficiently based on imaging of PET-CT. The volume of LV receiving higher dose in RT has high correlation with the volume of heart using sIMRT technique. It may pave the way for further exploring radiation induced cardiac injury in patients with breast cancer.