锥形束CT在头颈部和腹盆部肿瘤放疗摆位误差中的应用  

Analysis of setup error for head and neck tumors and for abdominal and pelvic tumors in radiotherapy with cone-beam computed tomography

作　　者：张大伟[1] 覃文[1] 苏世达[1] 梁杰 王仁生[1] 

机构地区：[1]广西医科大学第一附属医院放疗科,南宁530021

出　　处：《广西医科大学学报》2017年第12期1731-1734,共4页Journal of Guangxi Medical University

基　　金：广西壮族自治区卫生厅自筹经费课题资助项目(No.Z2017559)

摘　　要：目的:探讨锥形束CT(CBCT)在头颈部和腹盆部肿瘤放疗摆位误差中的应用,为计划靶区(PTV)的外放提供依据。方法:选取2016年3月至2016年11月广西医科大学第一附属医院收治的44例头颈部和36例腹盆部肿瘤患者,分别采用热塑头颈肩面罩和真空负压袋固定,首次以及每周第一次放疗均行CBCT,将CBCT图像与计划CT图像配准得到摆位误差;对于任意方向摆位误差,头颈部>3 mm、腹盆部>5 mm在线移床后再行CBCT。结果:校位前头颈部摆位误差在前后、头脚、左右方向分别为(-0.32±0.84)mm、(0.49±1.19)mm、(-0.51±0.73)mm,校位后分别为(-0.14±0.51)mm、(0.19±0.75)mm、(-0.20±0.58)mm;校位前腹盆部摆位误差在3个方向分别为(0.89±2.56)mm、(-0.72±2.13)mm、(-0.83±2.17)mm,校位后分别为(0.34±1.61)mm、(-0.32±1.52)mm、(-0.28±1.75)mm,校位后头颈部和腹盆部摆位误差均变小,差异有统计学意义(P<0.05)。结论:腹盆部的摆位误差明显大于头颈部,采用CBCT可降低摆位误差,提高放疗摆位精度。Objective： To study setup error for head and neck tumors and for abdominal and pelvic tumors with CBCT in radiotherapy, and provide reference for the proper margins of PTV. Methods： From March 2016 to November 2016, 44 patients with head and neck tumors and 36 patients with abdominal and pelvic tumors who received radiotherapy in our hospital were selected and fixed by the head-neck-shoulder thermoplastic mask and negative pressure vacuum pad, respectively. CBCT was performed before every treatment. The scans were registered to the planning CT to get the setup error. CBCT was done again after online correction when the setup error was greater than 3 mm for head and neck tumors and were greater than 5 mm for abdominal and pelvic tumors. Results ： The setup error for head and neck tumors before correction in anterior-posterior, superior-inferior and left-right directions were （-0. 32±0. 84） mm, （0.49±1. 19） mm and （-0. 51 ±0. 73） mm. The setup error reduced to （-0. 14±0. 51） mm, （0. 19±0. 75） mm, and （-0. 20±0. 58） mm respectively after correction. The setup error for abdominal and pelvic tumors before correction were （0. 89 ±2. 56） mm, （-0. 72 ±2. 13 ） mm and （-0. 83±2. 17） mm, and reduced to （0. 34±1.61） mm, （-0. 32±1.52） mmand （-0. 28±1.75） mmin the three direction respectively after correction. Setup error after correction was significantly reduced （P〈0. 05）. Conclusion： The setup error for the head and neck tumors was significantly greater than that of abdominal and pelvic tumors. CBCT could reduce the setup error and improve the accuracy of radiotherapy.

关 键 词：锥形束CT 摆位误差 PTV 调强放疗 

分 类 号：R730.55[医药卫生—肿瘤]