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基于自主呼吸控制三维CT分析周围型肺癌四维CT各时相大体肿瘤体积伪影
戚焕鹏, 李建彬, 张英杰, 邵倩, 范廷勇, 徐敏, 梁超前, 尚东平
250117 济南,山东省放射肿瘤学重点实验室山东省肿瘤医院放疗科
Analysis of GTV artifacts in each phase of four dimensional CT for peripheral lung cancer based on three dimensional CT assisted with active breathing control
QI Huan-peng, LI Jian-bin, ZHANG Ying-jie, SHAO Qian, FAN Ting-yong, XU Min, LIANG Chao-qian, SHANG Dong-ping
Department of Radiation Oncology, Shandong Tumor Hospital ;Shandong Province Key Laboratory of Radiation Oncology;Ji′nan 250117,China Corresponding author:LI Jian-bin, Email:lijianbin@msn.com
Abstract：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 (CTFB) 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 Devmax 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 GTV30 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 Devmax 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.
QI Huan-peng,LI Jian-bin,ZHANG Ying-jie et al. Analysis of GTV artifacts in each phase of four dimensional CT for peripheral lung cancer based on three dimensional CT assisted with active breathing control[J]. Chinese Journal of Radiation Oncology, 2012, 21(6): 508-511.
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