改良式体位固定技术在胸腹部肿瘤放疗中的应用

目的:探讨两种不同体位固定技术对胸腹部肿瘤放疗重复摆位精度的影响。方法:60例需行放疗的胸腹部肿瘤患者按随机数字法分为对照组:翼形板+真空垫固定体位(30 例)；观察组:改良式体位固定技术即热塑体膜联合体板+真空垫组(30 例)。所有患者首次放疗前行CBCT扫描，以后每周扫描一次，比较两组X轴(左右)、Y轴(头脚)和Z轴(腹背)方向的摆位误差值。结果:对照组X轴、Y轴和Z 轴方向上摆位误差分别为(4.03±0.15)mm、(3.62±0.23)mm和(3.74±0.31)mm。观察组X 轴、Y 轴和Z轴方向上摆位误差分别为(3.91±0.29)mm、(3.54±0.34)mm 和(2.86±0.20)mm。两组在Z轴方向的摆位误差比较差异具有统计学意义(P<0.05)。结论:改良式体位固定技术可以改善胸腹部肿瘤患者放疗时摆位的舒适度，利于体位的固定，提高患者治疗时摆位的重复性和精度。

Application of improved posture fixation technique in radiotherapy of thoracic and abdominal tumors

Objective:To investigate the effect of two different position fixing techniques on the accuracy of radiotherapy and radiotherapy for thoracic and abdominal tumors.Methods:Sixty patients with thoracic and abdominal tumors requiring radiotherapy were randomly divided into control group (30 cases) and observation group (30 cases) according to random number method.CBCT scans were performed before the first radiotherapy and once a week after the first radiotherapy.The X-axis (left and right)，Y-axis (head and foot) and Z-axis (abdominal and dorsal) alignment errors were compared between the two groups.Results:In the control group，the positioning errors of X axis，Y axis and Z axis were (4.03±0.15)mm，(3.62±0.23)mm and (3.74±0.31)mm，respectively.The position errors of X axis，Y axis and Z axis in observation group were (3.91±0.29)mm，(3.54±0.34)mm and (2.86±0.20)mm respectively.The difference of set-up errors between the two groups in Z axis was statistically significant (P<0.05).Conclusion:Modified posture fixation technique can improve the comfort of patients with thoracic and abdominal tumors during radiotherapy，which is conducive to posture fixation and improve the reproducibility and accuracy of the fixed position.