Abstract：Objective To investigate the difference between conventional and contrast-enhanced four-dimensional computed tomography (4DCT) scans in delineating the gross tumor volume (GTV) in different phases and constructing the internal gross tumor volume (IGTV) in primary thoracic esophageal cancer. Methods Twenty-five patients with thoracic esophageal cancer, including 8 upper-thoracic, 9 middle-thoracic, and 8 lower-thoracic, sequentially underwent conventional and contrast-enhanced 4DCT scans during normal breathing. The GTVs were delineated by a physician under the same standard using conventional plain 4DCT images, and the IGTVs were constructed accordingly. After one month, the GTVs were delineated by contrast-enhanced 4DCT images and IGTVs were constructed by the same physician. Results The coefficient of variation for the target volume based on the contrast-enhanced 4DCT images was smaller than that based on the plain 4DCT images. There were no significant differences in the length of the z axis of GTV, GTV, and IGTV between contrast-enhanced and plain 4DCT images in patients with upper-and lower-thoracic esophageal cancer (P=0.529 and 0.110;P=0.158 and 0.416;P=0.147 and 0.615). However, in patients with middle-thoracic esophageal cancer, the length of the z axis of GTV, GTV, and IGTV were significantly different between contrast-enhanced and plain 4DCT images (P=0.005, 0.035, and 0.021, respectively). Conclusions Contrast-enhanced 4DCT scan can reduce the error in delineating the target volume and construct a more accurate IGTV for patients with middle-thoracic esophageal cancer. However, it has no significant benefit in patients with upper-and lower-thoracic esophageal cancer.
Wang Jinzhi,Li Jianbin,Qi Huanpeng et al. Impact of contrast-enhanced 4DCT scan on delineating GTV and constructing IGTV in thoracic esophageal cancer[J]. Chinese Journal of Radiation Oncology, 2015, 24(2): 116-120.
[1]Wang W, Li J, Zhang Y, et al. Comparison of patient-specific internal gross tumor volume for radiation treatment of primary esophageal cancer based separately on three-dimensional and four-dimensional computed tomography images[J]. Dis Esophagus,2014,27(4):348-354.DOI:10.1111/dote.12089. [2]Zhao KL, Liao Z, Bucci MK, et al. Evaluation of respiratory induced target motion for esophageal tumors at the gastroesophageal junction[J]. Radiother Oncol,2007,84(3):283-289. [3]李奉祥,李建彬,张英杰,等.四维影像在肿瘤放射治疗中的应用[J].中华肿瘤杂志,2011,33(10):721-725.DOI:10.3760/cma.j.issn.0253-3766.2011.10.001. [4]Muijs CT, Beukema JC, Pruim J, et al. A systematic review on the role of FDG-PET/CT in tumour delineation and radiotherapy planning in patients with esophageal cancer[J]. Radiother Oncol,2010,97(2):165-171.DOI:10.1016/j.radonc.2010.04.024. [5]侯栋梁,方彤,刘辉,等.CT/MR图像融合在食管癌精确放疗大体肿瘤靶区勾画中的应用价值[J].中华放射医学与防护杂志,2014,34(2):129-132.DOI:10.3760/cma.j.issn.0254-5098.2014.02.013 [6]张惠茅,杨海山.螺旋CT在食管癌检查中的临床应用[J].临床放射学杂志,2001,20(6):433-435. [7]Lorchel F, Dumas Jl, Noel A, et al. Esophageal cancer:Determination of internal target volume for conformal radiotherapy[J].Radiother Oncol,2006,80(3):327-332. [8]Yaremko BP, Guerrero TM, McAleer MF, et al. Determination of respiratory motion for distal esophagus cancer using four-dimensional computed tomography[J].Int J Radiat Oncol Biol Phys,2008,70(1):145-153. [9]Patel AA, Wolfgang JA, Niemierko A, et al. Implications of respiratory motion as measured by four-dimensional computed tomography for radiation treatment planning of esophageal cancer[J]. Int J Radiat Oncol Biol Phys,2009,74(1):290-296.DOI:10.1016/j.ijrobp.2008.12.06. [10]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[J]. Int J Radiat Oncol Biol Phys,2011,79(2):588-595.DOI:10.1016/j.ijrobp.2010.03.045 [11]Cattaneo GM, Passoni P, Sangalli G, et al. Internal target volume defined by contrast-enhanced 4D-CT scan in unresectable pancreatic tumour:evaluation and reproducibility[J]. Radiother Oncol,2010,97(3):525-529.DOI:10.1016/j.radonc.2010.08.007 [12]杨焕军,蒋国梁,傅小龙,等.胸部增强CT扫描对肺癌大体肿瘤体积勾画的影响[J].中华放射肿瘤学杂志,2005,15(4):123－125. [13]吴开良,蒋国梁,王鹏,等.肺癌三维适形放射治疗靶体积确定的影响因素[J].中华放射肿瘤学杂志,2003,12(3):46-49. [14]Zhou SM, Bentel GC, Lee CG, et a1. Differences in gross target volumes on contrast VS.Noncontrast CT scans utilized for conformal radiation therapy treatment planning for prostate carcinoma[J]. Int J Radiat Oncol Biol Phys,1998,42(1):73-78. [15]Shibamoto Y, Naruse A, Fukuma H, et a1. Influence of contrast materials on dose calculation in radiotherapy planning sing computed tomography for tumors at various anatomical regions:a prospective study[J]. Radiother Oncol,2007,84(1):52-55.
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