宫颈癌患者膀胱充盈度一致性对模拟机位置验证的影响

Effect of bladder filling consistency on position verification of simulators in patients with cervical cancer

目的利用模拟机验证膀胱充盈与否对于宫颈癌患者体位验证的影响。方法选择经病理证实的宫颈癌患者50例,年龄38~60岁,平均年龄46岁。在其定位时提前40 min喝水憋尿,待到模拟验证时采集3组数据,分别为膀胱排空1次和膀胱充盈2次时X轴(Lat,即左右方向)、Y轴(Lng,即头脚方向)、Z轴(Vrt,即高度方向)三个方向上的位移值,并对3组数据进行统计分析。结果试验共获得150组数据,膀胱充盈后两次比较左右(Lat)、头脚(Lng)、高度(Vrt)三个方向上,差异无统计学意义(P均>0.05);比较膀胱排空和充盈的两组数据得出,左右(Lat)和头脚(Lng)方向上差异均有统计学意义(0.168 cm±0.021 cm vs 0.026 cm±0.010 cm,0.464 cm±0.024 cm vs 0.066 cm±0.012 cm;t=5.965、14.51,P<0.05),高度(Vrt)方向上差异无统计学意义(P>0.05)。结论宫颈癌患者放射治疗前模拟机位置验证时膀胱需要充盈。利用模拟机能够准确分析宫颈癌患者膀胱充盈对于调强放射治疗中射野中心的移位影响,减少定位、摆位中误差,是一种可靠的、便捷的位置验证方法。

Objective To study the effect of bladder filling on position verification of cervical cancer patients by using simulator.Methods Fifty patients with cervical cancer confirmed by pathology were enrolled,which aged 38-60 years old with mean age of 46 years old.All of the patients were asked to drink and hold urine 40 minutes before positioning.Three sets of data were collected during simulation verification,which were displacement in 3 directions at X-axis(Lat,left-right direction),Yaxis(Lng,head-foot direction)and Z-axis(Vrt,height direction)for bladder emptying 1 time and bladder filling 2 times.Statistical analysis was performed.Results A total of 150 sets of data were obtained.There were no significant differences in 3 directions of Lat,Lng and Vrt after bladder filling(P>0.05).Compared the data of bladder emptying and filling,the differences in Lat and Lng direction were statistically significant(0.168 cm±0.021 cm vs 0.026 cm±0.010 cm,0.464 cm±0.024 cm vs 0.066 cm±0.012 cm;t=5.965,14.51,P<0.05),while there was no statistically significant difference in Vrt direction(P>0.05).Conclusion It is demonstrated that bladder needs to be filled in position verification of simulator before radiotherapy in cervical cancer patient.The simulator can accurately analyze the effect of bladder filling in patients with cervical cancer on displacement of field center in intensity modulated radiation therapy,and simulator verification is a reliable and convenient method to reduce errors in positioning.