摘要
目的基于自主呼吸控制（ABC）辅助三维cT（3DCT）探讨周围型肺癌四维cT（4DCT）各时相大体肿瘤体积（GTV）伪影大小及相关因素。方法19例周围型肺癌患者依次行胸部自由呼吸3DCT（CTFB）和4DCT及ABC辅助平静吸气末屏气（cTEIH）和呼气末屏气（cTEEH）3DCT，分别计算基于cTFB勾画所得GTV（GTVFB）和基于4DCT各时相勾画所得GTV与参照GTV（GTVtef）间相对变异（Devref）。用Spearman法分析GTVref与GTV的Devmax相关性，多元回归分析肿瘤头脚方向运动与Devmax间相关性。结果GTVFB的Devref最大，中位数为17．83％；4DCT中GTV30的Devref最大，中位数为17．20％。GTVEIH与Devmax呈负相关（r=-0．691，P=0．001）。GTVFB及4DCT各时相GTV的Devref与肿瘤头脚方向运动幅度均呈正相关（r=0．323—0．617，P=0．005～0．150）。GTVref大小和肿瘤头脚方向运动幅度对Devmax影响的偏回归系数分别为-0．500和0．583，P=0．002、0．001。结论基于4DCT扫描所得周围型肺癌各时相GTV伪影大小存在差异，且位移对伪影的影响大于体积的影响，可通过控制呼吸运动来减小靶区位移继而减小伪影。
Objective To analyze artifacts of gross tumor volume （GTV） and correlated factors in each phase images of four dimensional CT （4DCT） for peripheral lung cancer based on three dimensional CT （3DCT） assisted with active breathing control. Methods Nineteen patients with peripheral lung cancer underwent 3DCT （ CTFs ） and 4DCT simulation scans during free breathing and then underwent 3DCT simulation scans in end inspiration hold （ CTEIH ） and end expiration hold （ CTEEH ） assisted with active breathing control. The relative deviations （Devref ） between the reference GTV （GTVref） and the GTVs delineated based on CTFB （ GTVFB ） and all phases of 4DCT were calculated respectively. Correlations between GTVref and Dev and between the tumor motion in the cranio-caudal （CC） direction and Devref were analyzed. Results The maximum median Devref of GTV was GTVFB with 17.83%, and the maximum median Devref of the GTV in all phases of 4DCT was GTY30 with 17.20%. A significant negative correlation was found between GTVEIH and Devmax （r = -0. 691, P = 0. 001 ）. The Devref was correlated with the tumor motion amplitude in the CC direction （ r = 0. 323 - 0. 617, P = 0. 005 - 0. 150 ）. The partial regression coefficient of influence of GTVref size and motion amplitude in the CC direction to the tumor Dev were - 0. 500 and 0. 583, P = 0. 002 and 0. 001, respectively. Conclusions The GTV artifacts in different phase of 4DCT for the peripheral lung cancer were different to each other, and the influence of target displacement to artifacts was larger than that of target volume, so artifacts could be reduced by controlling breathing to reduce target displacement.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2012年第6期508-512,共5页
Chinese Journal of Radiation Oncology
基金
山东省自然科学基金项目（ZR2011HM004）
山东省科技发展计划项目（2012GSF11839）
