激光定位坐标尺提高乳腺癌保乳术后放疗摆位精度的研究

Study of precise positioning of post-breast conservative surgery radiotherapy placement using laser positioning coordination system in breast cancer patients

目的验证保乳术后放疗患者应用激光定位坐标尺描画体表标志线的摆位误差及其临床应用价值。方法前瞻性收集2022年1月至2023年9月在内蒙古医科大学附属医院放疗科进行放疗的乳腺癌保乳术后患者45例,2个试验组各15例患者,分别使用初始版(初始坐标尺组)和升级版(升级坐标尺组)激光定位坐标尺描画体表标志线试验,另15例患者应用常规方法描画体表标志线(常规组)作为对照。所有患者均采用螺旋断层放疗,并记录患者每次放疗前左右方向(X)、头脚方向(Y)、腹背方向(Z)及旋转角度的误差值。用t检验分析两个坐标尺组和常规组患者摆位误差的差异。结果45例患者共获取675套摆位误差数据(共2700个数值),初始坐标尺组的X、Y、Z方向和旋转角度的摆位误差分别为(3.10±2.43)mm、(4.36±3.45)mm、(2.29±2.49)mm、0.95°±0.88°;升级坐标尺组相应的摆位误差分别为(2.88±2.28)mm、(3.58±2.95)mm、(2.40±2.54)mm、0.70°±0.70°;常规组相应的摆位误差分别为(4.32±3.48)mm、(5.49±4.74)mm、(2.61±3.38)mm、1.22°±1.16°。初始坐标尺组与常规组比较,摆位误差在X、Y方向和旋转角度的差异有统计学意义(t=4.32、2.89、2.78,P<0.001、=0.004、=0.006);升级坐标尺组与常规组比较,摆位误差在X、Y方向和旋转角度的差异有统计学意义(t=5.20、5.14、5.82,P值均<0.001);初始坐标尺组与升级坐标尺组比较,摆位误差在Y方向及旋转角度的差异有统计学意义(t=2.58、3.41,P=0.010、0.001)。结论激光定位坐标尺辅助描画体表标志线能够明显减少X、Y方向和旋转角度的摆位误差,升级版激光定位坐标尺较初始版能够进一步减少Y方向及旋转角度的摆位误差,有临床应用价值。

Objective To compare the positioning errors in tracing the body surface markers between radiotherapy placement with or without using the laser positioning coordination system in post-breast conservative surgery patients,and to verify the clinical value of the laser positioning coordination system.Methods A total of 45 post-breast-conservative surgery patients who underwent radiotherapy in Department of Radiation Oncology of the Affiliated Hospital of Inner Mongolia Medical University from January 2022 to September 2023 were prospectively collected.In the experimental group 1(n=15),the initial version of the laser positioning coordination system was employed to trace the body surface markers.In the experimental group 2(n=15),the upgraded version of the laser positioning coordination system was adopted to draw the body surface markers.In the control group(n=15),the body surface markers were traced with conventional approach.All patients were treated with spiral tomotherapy(TOMO),and the error values in the left and right directions(X),head and foot directions(Y),ventral and dorsal directions(Z),and rotation angles(ROLL)before each radiotherapy were recorded.The differences in the positioning errors among the three groups were analyzed by t-test.Results The positioning errors in the X,Y,Z directions and ROLL in the experimental group 1 were(3.10±2.43)mm,(4.36±3.45)mm,(2.29±2.49)mm and 0.95°±0.88°,and(2.88±2.28)mm,(3.58±2.95)mm,(2.40±2.54)mm,and 0.70°±0.70°in the experimental group 2,and(4.32±3.48)mm,(5.49±4.74)mm,(2.61±3.38)mm and 1.22°±1.16°in the control group,respectively.Statistical significance was observed in the differences of positioning errors in the X,Y directions and ROLL between the experimental group 1 and control group(t=4.32,2.89,2.78,P<0.001,=0.004,=0.006),respectively.Statistical significance was detected in the differences of positioning errors in the X,Y directions and ROLL between the experimental group 2 and control group(t=5.20,5.14,5.82,all P<0.001).Statistical significance was noted in the differences of positioning errors in the Y direction and ROLL between the experimental group 1 and 2(t=2.58,3.41,P=0.010,0.001).Conclusion The laser positioning coordination system-assisted tracing the body surface marking line can significantly reduce the positioning errors in the X and Y directions and ROLL,and the upgraded version of the laser positioning coordination system can further reduce the positioning errors in the Y direction and ROLL compared with the initial version,which is of high clinical application value.