CAJ | 학술논문

目的：应用千伏级锥形束CT （kV级CBCT）图像引导放疗技术评估肝癌患者分次放疗间位置的变化。方法15例肝癌患者，每例患者在放疗前行CBCT扫描，每周1～3次，共获取121幅 CBCT图像。离线下以肝脏、椎体外轮廓分别为参照物完成CBCT图像与计划CT的配准，将配准结果定义为分次放疗间肝脏及椎体位置的变化，将两者配准结果的差值定义为肝脏相对于椎体位置的变化，分别予以评估。结果分次放疗间在三维方向，肝脏位移的绝对值以上下方向最大6.3 mm （0～19.3 mm）、左右方向次之2.3 mm（0～16.0 mm）、前后方向最小1.5 mm （0～7.6 mm）（P＜0.001）；椎体位移的绝对值以上下方向最大6.0 mm （0～18.0 mm）、左右方向次之3.0 mm （0～16.0 mm）、前后方向最小2.0 mm （0～10.0 mm）（P＜0.05）；肝脏相对于椎体位移的绝对值以上下方向最大4.8 mm （0.1～19.3 mm）、左右方向次之2.0 mm （0～8.6 mm）、上下方向最小1.4 mm （0～10.3 mm）（P＜0.001）。若通过配准椎体校正患者位置，放疗时左右、上下、前后方向肝脏位移的绝对值可能增大，可能性分别为39.7％、42.1％、43.0％。结论椎体不适于作为肝癌图像引导放疗的参照物。
목적：응용천복급추형속CT （kV급CBCT）도상인도방료기술평고간암환자분차방료간위치적변화。방법15례간암환자，매례환자재방료전행CBCT소묘，매주1～3차，공획취121폭 CBCT도상。리선하이간장、추체외륜곽분별위삼조물완성CBCT도상여계화CT적배준，장배준결과정의위분차방료간간장급추체위치적변화，장량자배준결과적차치정의위간장상대우추체위치적변화，분별여이평고。결과분차방료간재삼유방향，간장위이적절대치이상하방향최대6.3 mm （0～19.3 mm）、좌우방향차지2.3 mm（0～16.0 mm）、전후방향최소1.5 mm （0～7.6 mm）（P＜0.001）；추체위이적절대치이상하방향최대6.0 mm （0～18.0 mm）、좌우방향차지3.0 mm （0～16.0 mm）、전후방향최소2.0 mm （0～10.0 mm）（P＜0.05）；간장상대우추체위이적절대치이상하방향최대4.8 mm （0.1～19.3 mm）、좌우방향차지2.0 mm （0～8.6 mm）、상하방향최소1.4 mm （0～10.3 mm）（P＜0.001）。약통과배준추체교정환자위치，방료시좌우、상하、전후방향간장위이적절대치가능증대，가능성분별위39.7％、42.1％、43.0％。결론추체불괄우작위간암도상인도방료적삼조물。
Objective To investigate the interfraction variability of position for liver cancer patients in radiotherapy by kilovoltage cone-beam computed tomography (kV CBCT).Methods 15 case with liver cancer were studied.For each patient,CBCT scan was processed in the treatment position once to three times per week immediately before radiotherapy,and 121 CBCT scans were obtainded in all.In the offline study,each CBCT liver and vertebral body were alinged with planned CT scan,and the results were de-fined as interfraction variability of liver position and vertebral body position,respectively.The difference between results was defined as variability of liver position related to vertebral body.while spatial variabili-ties were evaluated.Results The superior-inferior amplitude of liver motion was the largest,followed by left-right amplitude,and the smallest was anterior-posterior amplitude with data of 6.3 mm (0~19.3), 2.3 mm (0~16.0)and 1.5 mm (0~7.6),respectively (P<0.001).The superior-inferior amplitude of vertebral body motion was the largest, followed by left-right amplitude, and the smallest was anterior-posterior amplitude,with data of 6.0 mm (0~18.0),3.0 mm (0~16.0)and 2.0 mm (0~10.0),re-spectively (P<0.05).The superior-inferior amplitude of liver related to vertebral body motion was the largest,followed by left-right amplitude,and the smallest was anterior-posterior amplitude,with data of 4.8 mm (0.1~19.3),2.0 mm (0~8.6)and 1.4 mm (0~10.3),respectively (P<0.001).After pa-tients position alignment using vertebral body,the amplitude of liver motion was increased,and possibili-ties in left-right,superior-inferior and anterior-posterior directions were 39.7%,42.1% and 43.0% re-spectively.Conclusions Using vertebral body as surrogate is not suitable for liver cancer IGRT.