体质量指数对图像引导宫颈癌放射治疗摆位误差的影响  

Effect of body mass index on setup errors in cervical cancer treated with imageguided radiotherapy

作　　者：刘云[1] 余娴[1] 肖何[1] 胡南[1] 王阁[1] 

机构地区：[1]第三军医大学大坪医院野战外科研究所肿瘤中心,重庆400042

出　　处：《第三军医大学学报》2016年第4期419-421,共3页Journal of Third Military Medical University

摘　　要：目的观察体质量指数(body mass index,BMI)对图像引导放射治疗(image guided radiotherapy,IGRT)宫颈癌患者摆位误差的影响,探讨IGRT宫颈癌患者的最佳体位。方法收集IGRT宫颈癌患者30例,按BMI分为2组:BMI≥24 kg/m^2组,9例;BMI<24 kg/m2组,21例。锥形束CT扫描,俯卧位68次,仰卧位73次,CT图像进行灰度自动配准计算出X、Y、Z轴方向的校正前摆位误差,分析宫颈癌患者IGRT最佳治疗体位,并根据扩边公式2.5Σ+0.7δ计算出最佳体位扩边值。结果未考虑BMI的情况下,俯卧与仰卧位摆位误差均无统计学差异(P>0.05);BMI<24 kg/m2组,仰卧位与俯卧位在X、Y轴摆位误差无统计学差异(P>0.05),而在Z轴上仰卧位误差为(-0.112±0.041)cm,俯卧位误差为(0.028±0.024)cm,二者有统计学差异(t=-3.186,P=0.002),俯卧位扩边值0.668、1.206、0.335 cm;BMI≥24 kg/m2组,仰卧位与俯卧位在X、Y轴摆位误差无统计学差异(P>0.05),在Z轴仰卧位摆位误差为(0.061±0.045)cm,俯卧位摆位误差为(-0.26±0.031)cm,二者有统计学差异(t=5.832,P<0.001),仰卧位扩边值0.313、1.663、0.501 cm。结论 BMI<24 kg/m2组,俯卧位Z轴方向误差显著小于仰卧位,BMI≥24 kg/m2组,仰卧位的Z轴方向误差显著小于俯卧位,2组在X、Y轴方向的摆位误差无统计学差异。Objective To investigate the best position in image-guided radiotherapy （IGRT） for uterine cervix cancer（UCC）. Methods Based on body mass index （BM]）, all the patients were divided into BMII〉24 group （9 patients） and BMI 〈 24 group （21 patients）. All the patients were scanned by cone beam computerized tomography（CBCT） , including 68 scans in prone position and 73 scans in supine position. The scanned images were analyzed by grayscale color automatic registration to get the setup errors before correction in X, Y and Z directions. The best position in IGRT for UCC was studied, and the margins of the best position were calculated by formula 2.5E ＋ O. 78. Results Without the disturbance of BMI, the setup errors had no significant difference between supine position and prone position （ P 〉 0. 05 ）. In the group of BMI 〈 24, the setup errors in X and Y directions had no significant difference between supine position and prone position（ P 〉 0. 05 ） , but the supine position error was - 0.112±0. 041 cm and the prone position error was O. 028 _＋ 0. 024 cm in Z direction, with significant differences （t = -3. 186, P = 0. 002）, and the margins of prone position were 0. 668, 1. 206, and 0. 335 cm. In the group of BMI≥24, the setup errors in X and Y directions had no significant difference between supine position and prone position （P 〉 0. 05 ） , but the supine position error was 0. 061 ±0. 045 cm and prone position was -0.26±0. 031 cm in Z direction, with significant difference （t = 5. 832, P 〈 0. 001 ） , and the margins of supine position were 0. 313 cm, 1. 663 cm, and 0. 501 cm. Conclusion The group of BMI 〈 24, the setup errors of prone position are significantly less than those of supine position in Z direction, while in the group of BMI ≥24, the setup errors of supine position are significantly less than those of prone positionin Z direction. Between the 2 group the setup errors have no statistical difference in X, Y directions.

关 键 词：宫颈癌 图像引导放射治疗 摆位误差 体质量指数 

分 类 号：R730.55[医药卫生—肿瘤] R737.33[医药卫生—临床医学]