CAJ | 학술논문

目的研究千伏级锥形束CT (CBCT)进行心脏勾画的可行性,并探讨计划CT上进行心脏勾画的外放标准.方法选取接受放疗的早期非小细胞肺癌患者15例,每次治疗前拍摄CBCT进行摆位误差纠正,利用每位患者前10次CBCT进行研究.在每次CBCT图像上按照统一标准进行心脏勾画,比较基于计划CT和CBCT心脏勾画的差异以及不同扫描时机CBCT勾画心脏的重复性,测量基于计划CT获得心脏各个轴向外放距离.结果 15例患者计划CT获得的心脏体积均小于CBCT的(平均值为588、717 cm3,P=0.000),不同次数CBCT勾画的心脏体积基本相当(P=0.999),相同解剖层面与首次CBCT图像心脏范围的重复性达0.985±0.020,各套间也相似(P =0.070).基于计划CT勾画心脏时外扩距离左、右方向分别为(10.5±2.8)、(5.9±2.8)mm,上、下方向分别为(2.2±1.6)、(3.3±2.2)mm,前、后方向分别为(6.7±1.1)、(4.5±2.5)mm.结论基于CBCT进行心脏勾画是可行的；未配备CBCT进行心脏勾画时建议在计划CT基础上对心脏左、右侧外放11、6mm,上、下方向外放3、4 mm,前、后方向外放7、5 mm.
목적 연구천복급추형속CT (CBCT)진행심장구화적가행성,병탐토계화CT상진행심장구화적외방표준.방법 선취접수방료적조기비소세포폐암환자15례,매차치료전박섭CBCT진행파위오차규정,이용매위환자전10차CBCT진행연구.재매차CBCT도상상안조통일표준진행심장구화,비교기우계화CT화CBCT심장구화적차이이급불동소묘시궤CBCT구화심장적중복성,측량기우계화CT획득심장각개축향외방거리.결과 15례환자계화CT획득적심장체적균소우CBCT적(평균치위588、717 cm3,P=0.000),불동차수CBCT구화적심장체적기본상당(P=0.999),상동해부층면여수차CBCT도상심장범위적중복성체0.985±0.020,각투간야상사(P =0.070).기우계화CT구화심장시외확거리좌、우방향분별위(10.5±2.8)、(5.9±2.8)mm,상、하방향분별위(2.2±1.6)、(3.3±2.2)mm,전、후방향분별위(6.7±1.1)、(4.5±2.5)mm.결론 기우CBCT진행심장구화시가행적；미배비CBCT진행심장구화시건의재계화CT기출상대심장좌、우측외방11、6mm,상、하방향외방3、4 mm,전、후방향외방7、5 mm.
Objective To study the feasibility of contouring heart planning organ at risk volume (PRV) on kilovolt cone-beam CT (CBCT) images,and measure the margins for the PRV of heart based on planning CT images.Methods 15 early stage non-small cell lung cancer (NSCLC) patients accepted radiotherapy in our hospital were selected.For every case,CBCT scan was achieved before every fraction to correct the setup error,and the first 10 serious CBCT images were selected in present research.After contouring the heart on CBCT images according to the same standard,compared the differences of heart between CT and CBCT,analyzed the reproducibility of contouring the heart on different serious CBCT images,measured the margins in different axial direction from heart on planning CT to CBCT.Results The heart volume of planning CT was smaller than CBCTs with statistical difference (588 cm3 vs.717 cm3,P =0.000).The volumes based on different serious CBCT images were similar for every patient (P =0.999)and the coincidence of the hearts region on the same anatomical section between the first serious CBCT and others serious could reach to 0.985-± 0.020 without statistical significant difference (P =0.070).The mean margins for heart from planning CT to CBCT was (10.5 ± 2.8) mm,(5.9 ± 2.8) mm,(2.2 ± 1.6)mm,(3.3-± 2.2) mm,(6.7 ± 1.1) mm and (4.5 ± 2.5) mm in the left,right,anterior and posterior direction;respectively.Conclusions The PRV of heart contouring based on CBCT was feasible.If there were no CBCT,11 mm in left direction,6 mm in right direction,3 mm in head-foot direction,7 mm in the anterior direction,and 5 mm in posterior direction should be applied to obtain the PRV of heart.