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Comparative study of overall and stratified measurement of internal margin expansion of esophageal cancer based on four-dimensional computed tomography
ZHANG Ying-jie, LI Jian-bin, WANG Wei, TIAN Shi-yu, MA Zhi-fang, SHANG Dong-ping
Department of Radiation Oncology, Shandong Tumor Hospital and Institute;Shandong Province Key Laboratory of Radiation Oncology;Jinan 250117,China Corresponding author:LI Jian-bin, Email:lijianbin@msn.com
Abstract Objective To evaluate the difference of esophageal cancer internal margin expansion measured by contouring the overall or stratified GTVs parallel to the top, bottom and center level of adjacent vertebra based on 4DCT. Methods Based on T1 phase of 4DCT scanned for 13 patients with esophageal cancer, an radiation oncologist contoured the gross tumor volumes of 10 respiratory phases in treatment planning system, the center coordinates of target volumes were recorded. Then according to the top,bottom and center level of adjacent vertebra,target volumes on multiple CT slices of 10 respiratory phases were contoured, the center coordinates (x, y) and maximum diameters of GTVs were recorded. Internal margins of multiple esophageal cancer layers contoured according to the adjacent vertebra were calculated by the formula:IM=x(y)T1-T10－x(y)T1±(d T1-T10－d T1),then the maximum IM of the same direction were filtered. The relationship of three dimensional movement of esophageal cancer and the difference ofinternal margin expansion measured by the whole or layers of esophageal cancer were analyzed. Results The motion range of the whole esophageal cancer was 1.32 mm in left-right (x-axis) direction,1.09 mm in anterior-posterior (y-axis) direction, and 2.92 mm in cranial-caudal (z-axis) direction. It was similar in x and y directions (t=1.21,P=0.251), but different in x and z directions (t=－3.38,P=0.005), and different in y and z directions (t=－4.02,P=0.002).There were significant relationship between motion range in x and y directions (r=0.597,P=0.040), in x and z directions (r=0.662, P=0.019) and in y and z directions (r=0.723, P=0.008). The mean movement of whole esophageal cancer in left, right, anterior and posterior was －0.38,0.94,－0.62 and 0.47 mm, respectively;the mean maximum movementof esophageal cancer layers according to adjacent vertebra level was －1.83,2.21,－1.85 and 2.02 mm, respectively. There were significant differences of internal margin expansion by overall or stratified measurement of esophageal cancer in left, right, anterior and posterior dimensions (t=5.15,－4.58,3.50,－7.56,P=0.000,0.001,0.004,0.000). Conclusions There was significant relationship between motion range in thee dimensions, internal margin expansion measured by the overall esophageal cancer was less than that by stratified measurement.
ZHANG Ying-jie,LI Jian-bin,WANG Wei et al. Comparative study of overall and stratified measurement of internal margin expansion of esophageal cancer based on four-dimensional computed tomography[J]. Chinese Journal of Radiation Oncology, 2012, 21(2): 144-146.
ZHANG Ying-jie,LI Jian-bin,WANG Wei et al. Comparative study of overall and stratified measurement of internal margin expansion of esophageal cancer based on four-dimensional computed tomography[J]. Chinese Journal of Radiation Oncology, 2012, 21(2): 144-146.
[1] Udagawa H. Chemoradiotherapy:its effectiveness, toxicity, and perspective in the treatment of esophageal cancer. Ann Thorac Cardiovascurg,2009,15:359-361. [2] Pan CC, Kashani R, Hayman JA, et al. Intra-and inter-fraction esophagus motion in 3D-conformal radiotherapy:Implications for ICRU 62 definitions of internal target volume and planning organ at risk volume. Int J Radiat Oncol Biol Phys,2004,60:580-581. [3] Yamashita H, Kida S, Sakumi A, et al. Four-dimensional measurement of the displacement of internal fiducial markers during 320-multislice computed tomography scanning of thoracic esophageal cancer. Int J Radiat Oncol Biol Phys,2011,79:588-595. [4] Yaremko BP, Guerrero TM, McAleer MF, et al. Determination of respiratory motion for distal esophagus cancer using four-dimensional computed tomography. Int J Radiat Oncol Biol Phys,2008,70:145-153. [5] Zhao KL, Liao Z, Bucci MK, et al. Evaluation of respiratory-induced target motion for esophageal tumors at the gastroesophageal junction. Radiother Oncol,2007,84:283-289.
2012, Vol. 21 
