头颈肩面罩在鼻咽癌调强放疗中的固定效果与精度比较

The Fix Effects and Accuracy of the Head,Neck and Shoulder Mask in Intensity-modulated Radiotherapy of Nasopharyngeal Carcinoma

目的探讨头颈肩面罩在鼻咽癌调强放疗中的固定效果及前后期的固定精度的比较,为合理使用头颈肩面罩提供参考。方法选取鼻咽癌调强放疗的患者18例,头颈肩面罩固定,分别在放疗的第2周末、第4周末和第6周末在模拟定位机房拍摄验证片,采用验证片上的骨性标志与治疗计划系统输出的DRR图进行比较,记录其摆位误差。结果 18例患者在各个方向上的总体摆位误差分别为X轴左右方向(1.03±0.69)mm,Y轴头脚方向(1.09±0.65)mm,Z轴前后方向(0.81±0.54)mm,第6周与第2周相比差异有统计学意义(P<0.05)。结论头颈肩面罩有很好的体位固定效果,放疗的第6周末精度有所下降。

Objective To study the fix effects and accuracy of the head, neck and shoulder mask in intensity-modulated ra- diotherapy of nasopharyngeal carcinoma in order to provide reference for reasonably using the head, neck and shoulder mask. Methods Head, neck and shoulder mask was applied in 18 cases of nasopharyngeal carcinoma in the intensity-modulated radio- therapy, the DRR diagram output from treatment planning system with symbol of osteoarthritis of simulation validation film in the second weekend,fourth and sixth weekend were compared. Results The overall set-up error in 18 patients in three directions were （ 1.03 ~ 0.69） mm in the left and right （X） direction, （ 1.09 ~ 0.65 ） mm in the head and foot （Y） direction, （0.81 ~ 0.54） mm in the anterior and posterior（Z） direction. The difference between the sixth week and the second week was statistically signif- icant （ P 〈 0.05 ）. Conclusion The head, neck and shoulder mask may improve the precision of set-up, but the accuracy of the sixth week was down regulated.