左侧乳腺癌改良根治术后逆向调强放射治疗的摆位误差分析  

Set-up Error Analysis for The Inverse IMRT Plan in Left Breast Cancer After Modified Radical Surgery

作　　者：徐金济[1] 成俊[1] 李伟[1] 王明伟[1] 

机构地区：[1]南通大学附属南通第三人民医院放疗科,江苏南通226006

出　　处：《中国医学物理学杂志》2013年第5期4358-4359,4386,共3页Chinese Journal of Medical Physics

摘　　要：目的:利用电子射野影像系统(EPID)分析左侧乳腺癌改良根治术后行逆向调强放射治疗的摆位误差,为临床靶区和计划设定提供参考。方法:选择30例左侧乳腺癌改良根治术后需要行放疗的患者,利用EPID进行摆位误差的测定。每周两次将治疗过程中的电子射野影像系统所拍摄的正位和侧位片,与数字化重建图像(DRR)的验证片进行对比分析,计算误差。结果:经过292幅图像对比发现,患者在平日的摆位误差中,主要为身体前后方向(z轴)的误差,平均为(2.44±2.17)mm;其次为头脚方向(y轴),平均为(2.01±1.32)mm;左右方向(x轴)误差最小,平均(1.27±0.88)mm。结论 :使用电子射野影像系统能够有效地测定摆位误差,提高质量控制水平,乳腺癌改良根治术后采用调强放疗的摆位误差在可接受范围。Objective： To explore the setup errors use electronic portal imaging system in inverse intensity modulated radio- therapy （IMRT） for left breast cancer after modified radical surgery, and to provide evidence for clinical planning target volume and treat plans. Methods： Thirty patients with left breast cancer after modified radical surgery were treated with radiotherapy. Electronic portal imaging was performed for twice each week before each treatment at the position AP （gantry angle 0°） and LT （gantry angle 90°）,the set-up errors were analyzed by comparing the films of digitally reconstructed radiographs （DRR） with electronic portal imaging device （EPID）. Results： By compared with 292 films ,we found that patients in the daily set-up errors were mainly before and after position（z axis）, the average of （2.44±2.17） mm; followed by the head and feet position（y axis）, with the average of （2.01±1.32） mm; the smallest error was left and fight position（x axis）, with the average of （ 1.27± 0.88） mm. Conclusions：The use of electronic portal imaging system can effectively measured set-up errors and improve the quality of control level, the set-up errors in the inverse IMRT plan in left breast cancer after modified radical surgery were acceptable.

关 键 词：乳腺癌 改良根治 调强放疗 摆位误差 

分 类 号：R739.9[医药卫生—肿瘤] R815.6[医药卫生—临床医学]