Comparison of the patient-specific internal gross tumor volume for primary esophageal cancer based separately on three-dimensional and four-dimensional CT simulation images
WANG Wei*, LI Jian-bin, ZHANG Ying-jie, XU Min, FAN Ting-yong, SHAO Qian, SHANG Dong-ping
*Department of Radiation Oncology, Shandong Cancer Hospital& Institute;Shandong Provincial Key Laboratory of Radiation Oncology;Shandong Academy of Medical Sciences;Jinan 250117, China
Abstract：Objective To compare the position, volume and matching index (MI) of patient-specific internal gross tumor volume (IGTV) delineated by 4 different approaches based on three-dimensional and four-dimensional CT (3DCT and 4DCT) image for primary esophageal cancers. MethodsThirteen patients with primary esophageal cancer underwent 3DCT and 4DCT simulation scans during free breathing, and the patient were divided into group A (tumor located in the proximal thoracic esophagus) and B (tumor located in the mid-and distal thoracic esophagus). IGTV were delineated using four approaches:The gross tumor volume (GTV) contours from 10 respiratory phases were combined into IGTV10;IGTV2 was acquired by combining the GTV from 0% and 50% phases;IGTVMIP was the GTV contour delineated from the maximum intensity projection (MIP);IGTV3D was acquired from the enlargement of 3DCT-based GTV by each spatial direction on the motion amplitude measured in the 4DCT. Results Target movement in lateral (LR),anterio-posterior (AP),superio-inferior (SI) directions showed no statistically significant difference (0.11 cm, 0.09 cm, 0.18 cm, respectively;χ2=1.06,P=0.589),and there was no statistically significant difference in centroid positions between IGTV10 and IGTV2 orIGTV3Din group A (t=－2.24,－0.00,P=0.089,－1.000), MI between IGTV10 and IGTV2,IGTV10 andIGTV3D were 0.88,0.54, respectively.For group B, target movement amplitude in SI direction was bigger than in LR, AP (0.47 cm,0.15 cm,0.12 cm,χ2=12.00,P=0.002).There was no significant difference between IGTV10 and IGTV3D in LR, AP, SI (t=－0.80,－0.82,－1.16,P=0.450,0.438,0.285), MI was 0.59;but the target center coordinates was demonstrated significant difference in SI between IGTV10 and IGTV2 for group B (t=2.97,P=0.021), MI was 0.86. The volume of IGTVMIP was smaller than IGTV10(t=－2.84,P=0.025), but the position of IGTV10 and IGTVMIP were with no statistically significant difference in the LR, AP, SI (t=－0.25,0.84,－1.22,P=0.809,0.429,0.263), MI between IGTV10 and IGTVMIP was 0.78. Conclusions Patient-specific IGTV can be acquired from 4DCT with correct target coverage while avoiding a geographic miss for the thoracic esophageal cancer,but IGTV2 and IGTVMIP can not contain all the information about primary tumor position, shape, and size at different phases of the respiratory cycle.
WANG Wei*,LI Jian-bin,ZHANG Ying-jie et al. Comparison of the patient-specific internal gross tumor volume for primary esophageal cancer based separately on three-dimensional and four-dimensional CT simulation images[J]. Chinese Journal of Radiation Oncology, 2012, 21(1): 42-46.
[1] Vedam SS, Keall PJ, Kini VR, et al. Acquiring a four-dimensional computed tomography dataset using an external respiratory signal. Phys Med Biol,2003,48:45-62. [2] Keal P. 4-dimensional computed tomography imaging and treatment planning. Semin Radiat Oncol,2004,14:81-90. [3] 张书旭,周凌宏,陈光杰,等.4D-CT重建及其在肺癌放疗中的应用研究进展.中国辐射卫生,2008,17:375-377. [4] 孙宗文,陈明,邓小武. 四维CT在肺癌个体化放疗中的应用. 中华放射肿瘤学杂志,2008,17:71-74. [5] Ezhil M, Vedam S, Balter P, et al. Determination of patient-specific internal gross tumor volumes for lung cancer using four-dimensional computed tomography. Radiat Oncol,2009,4:1-14. [6] Harris EJ, Donovan EM, Yarnold JR, et al. Characterization of target volume changes during breast radiotherapy using implanted fiducial markers and portal imaging. Int J Radiat Oncol Biol Phys,2009,73:958-966. [7] Hashimoto T, Shirato H, Kato M, et al. Real-time monitoring of a digestive tract marker to reduce adverse effects of moving organs at risk (OAR) in radiotherapy for thoracic and abdominal tumors. Int J Radiat Oncol Biol Phys,2005,61:1559-1564. [8] Patel AA, Wolfgang JA, Niemierko A, et al. Implications ofrespiratory motion as measured by four-dimensional computedtomography for radiation treatment planning of esophagealcancer. Med Phys,2009,36:1610-1617. [9] 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. [10] 朱广迎,石安辉,吴昊.肺癌调强放疗中靶区规划新概念—IGTV和ICTV. 中华放射肿瘤学杂志,2006,15:72. [11] Kang Y, Zhang X, Chang JY， et al.4D Proton treatment planning strategy for mobile lung tumors. Int J Radiat Oncol Biol Phys,2007,67:906-914. [12] Rietzel E, Liu AK, Chen GT, et al. Maximum-intensity vulumes for fast contouring of lung tumors including respiratory motion in 4DCT planning. Int J Radiat Oncol Biol Phys,2008,71:1245-1252. [13] Underberg RW, Lagerwaard FJ, Slotman BJ, et al. Use of maximum intensity projections (MIP) for target volume generation in 4DCT scans for lung cancer. Int J Radiat Oncol Biol Phys,2005,63:253-260. [14] Muirhead R, McNee SG, Featherstone C, et al. Use of maximum intensity projections (MIPs) for target outlining in 4DCT radiotherapy planning. J Thorac Oncol,2008,3:1433-1438. [15] Seppenwoolde Y, Shirato H, Kitamura K, et al. Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy. Int J Radiat Oncol Biol Phys,2002,53:822-834. [16] Boldea V, Sarrut D, Sharp G, et al. Study of motion in a 4D-CT using deformable registration. Int J Radiat Oncol Biol Phys,2005,63:499-500. [17] Dieleman EM, Senan S, Vincent A, et al. Four-dimensional computed tomographic analysis of esophageal mobility during normal respiration. Int J Radiat Oncol Biol Phys,2007,67:775-780.
2012, Vol. 21 
